Load History Parameters in RAM Concept

The following creep/shrinkage models are implemented in RAM Concept Version 8 Update 2 and later:

• ACI 209.2R-08/GL 2000
• AS 3600-2018
• Eurocode 2-2004
• ACI 209R-92 (ECR Values)

General Parameters

Initial Load Application

The Initial Load Application represents the time when loads are first applied to the structure and becomes the start time of the first load history step specified. The input initial loading time should be based on the construction and shoring schedule of your specific project. For example, it is common in the United States for formwork to be removed anywhere between 3-7 days, which represents the time of initial loading.

RAM Concept uses the input Initial Load Application to calculate adjustment factors for creep. This adjustment is calculated internally for all creep/shrinkage models implemented in the program, including ACI 209R-92 which uses the ultimate creep factor defined in the ECR box of the Calc Options dialog. See Table 1 below for more details about this adjustment for each creep/shrinkage model.

Table 1. Initial Load Application Adjustments for Implemented Creep/Shrinkage Models

Cure Duration

The Cure Duration represents the time when the moist cure period ends and when shrinkage period begins. For creep/shrinkage models that distinguish between autogenous and drying shrinkage (AS 3600-2018 and Eurocode 2-2004), the cure duration marks the time at which the drying shrinkage period begins. The input Cure Duration is also used to calculate an adjustment factor for shrinkage strain for the ACI 209.2R-92 (ECR values) creep/shrinkage model (see Clause 2.5.3).

Ageing Coefficient

Actual creep behavior is affected by the rate of load application and the variation of concrete strength over time. To account for these effects, RAM Concept adjusts the creep strains using an ageing coefficient and uses the resulting modified creep strain in the cross-section strain compatibility calculations (age-adjusted effective modulus method). See Section 5.2 in ACI 209R-92 for more discussion. While the rigorous calculation of the coefficient is rather involved, this value can normally be taken as 0.8 with little loss in accuracy. More about the ageing coefficient can be found in this article.

External Shrinkage Restraint

External restraint to shrinkage is a simple way to account for cracking due to the gradual buildup of tensile stress that can occur when stiff supports restrain shrinkage movements. In general, as the input percentage increases, the tensioning stiffening effect will be reduced, cracking will occur at earlier times and lower loading levels, and load history deflections will increase. This effect should be distinguished from internal restraint to shrinkage due to reinforcement, which is rigorously calculated separately from external restraint to shrinkage and always included in RAM Concept’s load history calculations. More about external and internal restraint to shrinkage can be found in this article.

Internal and external shrinkage restraint effects are often approximated in long-term deflection calculations using one of the following methods:

1. Reduced modulus of rupture. ACI 435R-95 recommends using a reduced effective modulus of rupture of 4*sqrt(f’c) psi or 0.33*sqrt(f’c) Mpa (approximately half of the ACI design value) for slab systems subject to significant restraint.
2. Reduced cracking moment. In ACI 318-19, Bischoff’s tension stiffening equation reduces Mcr by 1/3 (Mcr’ = 2/3Mcr). In Eurocode 2-2004, the use of b = 0.5 (Clause 7.4.3) effectively reduces the cracking moment by 30%¹.

RAM Concept does not use these approximate methods to account for shrinkage because:

1. RAM Concept rigorously calculates the internal shrinkage restraint effect for each section, but the methods listed above include that effect (together with external restraint) in the reduction. Using a reduced modulus of rupture or cracking moment, then, would double count an effect that is always accounted for in the RAM Concept calculations.
2. For severely restrained slabs, use of the reductions noted above may underestimate the external shrinkage restraint effect. Bischoff states this as follows: “using a reduced cracking moment less than the assumed value of 2/3Mcr may be merited in cases with increased restraint at the supports².”

In the Load History Calc Options dialog, the user has the option of entering a specific percentage for external shrinkage restraint or selecting one of the pre-set options. The pre-set options are mapped to assumed percentages as tabulated below.                                                                                                                                                                                                                                                            

Table 2. Pre-Set External Shrinkage Restraint Options

Prior to Version 8 Update 2, a default value of 20% was used in new RAM Concept models. In Version 8 Update 2 and after, the default selection is None, which results in a shrinkage restraint of 0%. This setting may be appropriate for a typical, intermediate floor in a multi-story structure. However, a larger percentage may be more appropriate for other conditions (podium slab, transfer plate, basement slab, etc.).

References

¹ Gilbert, R.I and Ranzi, G., “Time-Dependent Behavior of Concrete Structures”, CRC Press, 2019.

² Bischoff, P., “Comparison of Existing Approaches for Computing Deflection of Reinforced Concrete”, ACI Structural Journal, 117 (1), 2020, pp. 231-240.

Code-Specific Parameters

The basic creep coefficient and basic shrinkage strains represent the base code values under standard conditions without the adjustment for time and other environmental factors. In general, these values can be determined automatically by RAM Concept (select “Code” in entry field) or input directly by the user (enter value in entry field). Using the default “Code” selection for these parameters will work well in most cases and is the recommended approach.

The remaining code-specific parameters are used to calculate adjustment factors that are applied to the base code values. The selections used for these parameters can vary significantly from project to project and region to region. The defaults used for these parameters in RAM Concept should be viewed as selections that may be appropriate for a variety of projects/regions, but not as endorsed selections to be used for all models.

Code-specific parameters that do not apply to a given creep/shrinkage model are automatically disabled when that model is selected for use.

ACI209.2-08/GL 2000

The ACI 209.2R-08/GL 2000 creep/shrinkage model is the default creep model for new models that are created when any of the following design codes are selected for use: ACI 318, CAN/CSA A23.3, IS 456. The GL2000 model was developed by Gardner and Lockman and is outlined in ACI 209.2-08.

The active Calc Options parameters for the ACI 209.2R-08/GL 2000 model and the default settings are summarized in the image and table below. The table also defines what value or equation is used when “Code” is selected for the active parameter.

AS 3600-2018

The AS 3600-2018 creep/shrinkage model is the default creep model for new models that are created when any of the AS 3600 design codes are selected for use.

The active Calc Options parameters for the AS 3600-2018 model and the default settings are summarized in the image and table below. The table also defines what value or equation is used when “Code” is selected for the active parameter.

Eurocode 2-2004

The Eurocode 2-2004 creep/shrinkage model is the default creep model for new models that are created when any of the Eurocode 2 or BS 8100 design codes are selected for use.

The active Calc Options parameters for the Eurocode 2-2004 model and the default settings are summarized in the image and table below. The table also defines what value or equation is used when “Code” is selected for the active parameter.

ACI209R-92 (ECR Values)

The ACI 209R-92 (ECR values) model was the only creep and shrinkage model implemented in RAM Concept prior to Version 8 Update 2. This creep/shrinkage model will automatically be selected in models that were created in one of those prior versions and opened in a version later than Version 8 Update 2.

Unlike the other creep/shrinkage models, the ACI 209R-92 (ECR Values) model uses the creep factor and shrinkage strain that are input in the ECR box in the Calc Options box instead of the basic creep and shrinkage strain parameters. The creep factor is defined as the ratio of total strain (elastic strain + creep strain) to elastic strain. According to ACI 209R-92, an average value of creep strain:elastic strain is 2.35. As a result, RAM Concept adopts a default creep factor of 1 + 2.35 = 3.35. The creep factor that is input in RAM Concept should represent the final ultimate creep value including all adjustment factors except the adjustment for initial load application (γ_la ), which is calculated automatically by the program. Similarly, the input shrinkage strain should represent the ultimate shrinkage strain including all adjustment factors except the adjustment for moist cure duration (γ_la ), which is calculated automatically by the program.

The ACI 209R-92 model calculates creep strain based upon the modulus of the mean concrete strength at time of loading. Since RAM Concept calculates curvatures based upon the concrete modulus value at 28 days, an adjustment is needed to convert creep strains to the code model values. A similar adjustment is needed for the modulus of rupture, which is calculated using the 28-day design concrete strength and then used for the concrete flexural tension strength in the tension stiffening equation. These adjustments are automatically calculated by the program for the ACI 209R-92 model in RAM Concept Version 8 Update 2 and later. 

The applicable Calc Options parameters for the ACI 209R-92 (ECR Values) model and the default settings are summarized in the image and table below.

See Also

Load History Article

Ram Concept - Load History Convergence

RAM Concept Load History Deflections and ACI Deflection Limits

Structural Product TechNotes And FAQs

***Note - The AS 3600-2018 Creep and Shrinkage Models were added in RAM Concept Version 8 Update 2. The information and recommendations on this page do not apply to that implemented creep and shrinkage model. We recommend updating to that version (or later) and taking advantage of that enhancement for load history deflection calculations.***

Please visit this page for information on the AS 3600-2018 model.

This tech note discusses how to determine the Creep Factor and Initial Load Application for the AS 3600 design code. RAM Concept uses the ACI 209 model for creep and shrinkage. The creep and shrinkage parameters outlined in AS 3600 need to be modified to fit this model.

Creep Factor

In general, the final (30-year) creep value after being modified by all appropriate adjustment factors should be input as the creep factor.

AS 3600 references a creep coefficient, which is defined as the ratio of creep strain to elastic strain. The creep factor in RAM Concept is defined as the ratio of total strain (elastic strain + creep strain) to elastic strain, or 1 + creep strain/elastic strain. The creep factor in RAM Concept then is equal to 1 + creep coefficient.

For AS 3600, the input creep factor is determined as follows:

1. Find the basic creep coefficient from Table 3.1.8.2
2. Factor basic creep coefficient by correction factors k2, k4, and k5
3. Add 1 to convert the creep coefficient to a creep factor
4. Use a correction factor to convert the maturity coefficient k3 to the ACI 209 age coefficient

See “Creep Coefficient Correction Factors” for more discussion on Steps 2 and 4 above.

Creep Coefficient Correction Factors

AS 3600 uses the correction factors k2, k3, k4, and k5 to convert the basic creep coefficient to a design creep coefficient at any time. See Equation 3.1.8.3 in AS 3600-09.

Factor k2 should be based on a 30 year time after loading.

Factor k3 is a maturity coefficient that accounts for the initial load application. This parameter is analogous to the parameter in ACI 209, which is automatically accounted for by RAM Concept. A correction factor should be calculated based on the discussion in the Initial Load Application section below to calibrate the ACI 209 model used by RAM Concept to match the AS 3600 model.

Factor k4 accounts for environmental factors and will vary from project to project.

Factor k5 is a modification for high strength concrete and is a function of the concrete strength.

Initial Load Application

ACI 209 is based on a 7-day initial load application time, while AS 3600 is based on a 28-day initial load application time. The Initial Loading Application value that is input into RAM Concept should always match the actual initial loading time of the real structure. The initial loading time will be based on the construction and shoring schedule of your project and not the standard values specified in the design code. For example, it is common in the United States for formwork to be removed anywhere between 3-7 days and this is what should drive the input of the Initial Load Application value in RAM Concept.

ACI 209 uses a modification factor to account for initial load application times other than 7 days. This factor is automatically determined by the program and should not be incorporated into the input creep value. In AS 3600, the k3 correction factor accounts for the initial load time. A correction factor should be applied to the input creep factor to match the k3 factor to the age coefficient in the ACI 209 model.

In the plot below, the red line represents the equation for the maturity coefficient in ACI 209. The blue line represents the equation for the k3 factor in AS 3600. The green line is the ratio of the coefficient in AS 3600 to the coefficient in ACI 209 and represents the calibration factor that should be applied to the input creep factor to calibrate the ACI 209 model to the AS 3600 model.

For a single load application time, the calibration factor determined from the green line is easily determined. However, most real load histories are more complicated and include many loading/unloading times. For these more complex cases, the initial load application time is generally the most influential on creep deflection and the factor associated with this time from the green line plotted above should be used. For example, if the actual initial load application time is 7 days, then the correction factor is between 1.4 and 1.5.

It should be understood that this calibration factor does not correspond to a single given loading time, but rather will be used by RAM Concept to try to adjust the ACI 209 curve (represented by the red line in the image above) for all specified loading/unloading times. There is not a way to make it match exactly for many different loading/unloading times. Since the curve is reasonably flat, using the calibration factor for the initial loading time will give reasonable results.

Creep Example

Determine the creep factor for a 32 MPa, 200 mm concrete slab in a temperate inland factor environment. Initial loading time is 14 days.

The basic creep coefficient from Table 3.1.8.2 is 3.4.

k2 = 1.2 (see Figure 3.1.8.3(a) at 30 years after loading)

k4 = 0.6 (for temperate inland environment, see 3.1.8.3)

k5 = 1.0 (f’c < 50 MPa, see 3.1.8.3)

calibration factor for k3 = 1.35 (from green line in calibration plot above for time of 14 days)

Creep Factor = 3.4*1.2*0.6*1.0*1.35 + 1 = 4.31

The actual initial loading time is 14 days. The Initial Load Application should be defined as 14 days in the Load History/ECR tab of the Calc Options dialog.

Shrinkage Strain

In AS 3600, the final shrinkage strain is defined as the design shrinkage strain and consists of two parts: autogenous shrinkage and drying shrinkage. The shrinkage strain that is input in RAM Concept is the final shrinkage strain, or the sum of the autogenous and drying shrinkage strains.

All appropriate adjustment factors to account for environment conditions should be included in the final shrinkage strain. The time-dependent factor k1(Figure 3.1.7.2) is accounted for automatically by RAM Concept through the ACI 209 model.

For AS 3600, the input shrinkage strain is determined as follows:

1. Calculate the final autogenous shrinkage strain using Equation 3.1.7.2(3)
2. Determine the basic drying shrinkage strain using Equation 3.1.7.2(5)
3. Factor the basic drying shrinkage strain by factors k1 and k4
4. Calculate final shrinkage strain by adding strain in Step 1 and 3.

Moist Cure Duration

The ACI 209 shrinkage model used in RAM Concept assumes that no shrinkage occurs during the moist cure duration period. The standard moist cure duration period is 7 days and correction factors are applied for other durations (see ACI 209R-92 Table 2.5.3). RAM Concept automatically calculates this correction.

AS 3600 references a time “after the commencement of drying” with respect to the drying shrinkage and this is the equivalent of the moist duration period used in RAM Concept. The input moist duration period should be the time that has elapsed between concrete setting and the commencement of drying.

Note that moist cure duration correction will have the most significant effect on early age deflection. Because of the unpredictable nature and variability of early age shrinkage, early age deflections should be used with caution. Section 67.7 in the RAM Concept Manual has more discussion on this topic.

Shrinkage Example

Determine the shrinkage strain for a 32 Mpa, 200 mm concrete slab in a temperate inland environment. Assume a moist cure duration period of 7 days.

The final autogenous drying shrinkage strain from Equation 3.1.7.2(3) is:

[(0.06*32) – 1.0]*50*10^-6 = 0.000046

The final basic drying shrinkage is 1000 x 10-6.

The basic drying shrinkage strain from Equation 3.1.7.2(4) is:

[1.0 – (0.008*32)]*1000*10^-6 = 0.000744

k4 = 0.6 (for temperate inland environment)

k1 = 1.22 (see Figure 3.1.7.2)

The adjusted basic drying shrinkage is:

1.22*0.6*(0.000744) = 0.000545

Final shrinkage strain = 0.000545 + 0.000046 = 0.000591

See Also

Load History Article

RAM Concept Load History Calc Options

RAM Connection CONNECT Edition V13 Update 4 (v13.4.0) Release Notes – Updated December 2020

Enhancements:

1. Seismic enhancements for AISC 345-16 and AISC 358-16. Update AISC seismic provisions to latest code for all moment connections for moment frames and bracing connections for bracing frames..

2. New gusset to brace interface connections for AISC / CSA / AS / NZS.    

• Forked plates
• Forked tee
• Slotted with cover plates
• Tee with cover plates
• Flattened tubular
• Rods           

3. New joint dialog for joint type selection.

4. New circular base plate for AISC.

5. Horizontal braces connections to support vertical offset and only connected to one beam.

6. Chevron to support only one brace

Resolved Issues:

• AISC 360 gusset base plate had some incorrect orientation relative to braces. This was corrected and now columns show correct orientation for all cases.
  
  
• AISC 360 tapered beam members were showing an error when a Tee section was selected for haunch. This was fixed and now all I and Tee sections can be defined as haunch.
  
  
• Plate detailing info was missing for splice packing plates. Now both the DXF and the parts report show the packing plates information correctly.
  
  
• AISC 360 directly welded connections did not calculate the web panel shear correctly for SMF framing system. This is fixed now and the panel shear is calculated correctly for all framing systems.
  
  
• AISC 360 HSS truss connections were not calculating correctly the local yielding for branches with rotated sections. This was corrected and now all limit states are calculated properly regardless the members orientation.

RAM Elements CONNECT Edition v16.03.00.101 Release 
Notes – Updated December 2020 (Under construction)

Enhancements:

1. Direct Analysis Method.

2. Update Masonry TMS 402-16.

3. iTwin Services - Design review

Resolved Issues:

• Some intermediate results were incorrectly being reported for bending design in AISI S100-16. These have been corrected and now the intermediate results are reported accordingly.
  
  
• Incorrect reduction factor was being considered for bending in circular hollow sections in AISI S100-16. This is now fixed.
  
  
• Load combinations per ASCE 7-16 were missing. These has been added for LRFD, ASD and service.
  
  
• Scissors Howe truss template was assigning incorrect description to members. This has been fixed and the template works correctly.
  
  
• Some results differences between the AISC Design Guide 9 (Torsional design) were spotted for single angles between the AISC 360-10 and the AISC 360-16. These has been corrected.

Problem Description

When trying to access Connection Design within STAAD.pro CONNECT Edition, you may be stopped with an error, 
---------------------------
This workflow is licensed with the RAM Connection license.
Without this license only a few sample connections will be available.
To use all the capabilities in this workflow, the relevant Additional License option should be selected on the Start Page.

Similarly, when trying to access Connection design within STAAD.pro SELECT Series 6, you may be stopped with an error, No license for Ram Connection is available. Only simple Beam-Column connections available for usage."

Solution

STAAD.Pro needs to be configured to Enable Ram Connection License usage.

STAAD.Pro CONNECT Edition 

Once you start the software, you will find the following License Configuration set up in bottom right-hand corner. Note the color of the indicator for RAM Connection. 

You will get a warning messages noted above if the Ram Connection indicator is grey and you try to use the Connection Design Workflow. 

To change the configuration click on the License configuration link on the left and check the option for Ram Connection, then Accept

When making changes to the License Configuration in STAAD.Pro CE, the user will be prompted, "Changes to STAAD.Pro license configuration will take effect after application is restarted. Would you like to restart STAAD.Pro now?"

STAAD.Pro V8i SS6

From inside the start-up page of STAAD.Pro, on the License Configuration, check the box for RAM Connection as shown here. 

You will get a warning message about "Additional License Selected"; this informs you that if you do not own a license of RAM Connection, you will incur a over-usage bill later.

Select 'Yes' if you own a license for RAM Connection or you are okay with the charge.

Now, go to the Misc. Options tab, make sure the box for "Use Ram Connection Product License" is checked if you have selected 'yes' in the last warning message.

P.S. There have been few cases, where the license selection in License Configuration has not saved the selection. Try un-checking / re-checking it. Then go to the Misc. Options and check the box for 'Use RAM Connection License" and clicking Apply followed by Accept. If the information is not getting saved and it has remained checked ; uninstall STAAD.Pro and reinstall it with full administrative privileges (right-click on the installation file and select the option "Run as administrator", though you are logged in as the administrator). Now go to the configuration, uncheck the box, click on apply and then re-check it , click on apply, followed by accept. Now RAM Connection should work fine.

See Also

Error getting a RAM Connection License

Tips for Using RAM Connection within STAAD.Pro [TN].

[[How do I prevent access to the RAM Connection tab within STAAD.Pro?]]

What is the load combination "Type" for?

In RAM Elements (and Ram Connection), every load combination is given a type that determines when the load combination is utilized. The figure below illustrates how several different types of combos could be used in a single file.

When I analyze the model all the combinations are grayed out. Why?

On the Analysis tab of the Process – Analyze model dialog box, the user indicates if second order analysis will be considered. This is required when using tension-only members or compression-only springs, but may be turned on for any model.

Whenever a second order analysis is performed, the program individually analyzes each selected load case and combination that is checked on the Condition tab.

If second order analysis is NOT performed, then the program only analyzes the selected load cases. The results for all combinations are generated using the principal of superposition, so the user can no longer uncheck individual combos.

Furthermore, if the user opts not to analyze certain load cases, any combinations including those load cases will not have any results available.

When I try to optimize including deflections, I cannot select any load combos. Why?

The program uses "Service" or "Service-Steel" type load combinations for checking beam deflections. If a model has only "Design" or "Design-Steel" combinations and no service combinations, this feature will not be available. Add at least one service combo (e.g. 1.0 DL + 1.0 LL) to access this feature.

When I try to enter loads on members or nodes I can't because the spreadsheet is grayed out. Why?

In the lower right hand corner of the program window is the Current Load Condition selection. If the selection is a load case, then you can enter loads for that load case on members, nodes, shells etc. If that selection is a load combination then you can view, but not edit or add to the existing loads.

Change the condition to a valid load case in order to add loads. 

Load cases that are associated with dynamic response spectrum analysis should not have any static loads at all. 

Can I copy and paste load case or load combinations from one file to another?

Yes, you can literally copy the data (ctrl+C) from one file to paste (ctrl+V) into another. You can also copy the data and paste into Excel for future use in another file. Note, the list box data like "Type" will be converted into integers during this process.

You can also save your load conditions from a complete model and then recover those load conditions in a new file. Those options, as well as the option for generating load combinations, are all under the Home Ribbon Menu - Load Conditions group.

When I use Skip Loading in the Continuous Beam module, why does the program combine all the load patterns into one (and over design the beam)?

Do I need to include load combinations with negative factors on lateral loads?

Default program generated load combinations only include positive factors on lateral wind or seismic loads. If the model is subject to equal magnitude, opposite direction lateral loads, then additional combinations should be manually added using negative load factors on those load cases. Or a custom Load Combination generator (.rag file) can be created to generate the additional load combinations.

If the opposite direction lateral loads should be applied to different members, as is often the case with wind loads which vary from the windward to the leeward surface, or models with tension-only members, then an additional negative direction load case should be added instead.

This is contrary to the behavior in RAM Structural System - Ram Frame, where rigid diaphragms and linear-elastic braces are the norm and hence load combinations with negative terms are the default.

Can I customize the Load Combination Generation template files?

Yes, in the Load Combinations Generation Dialog, at the lower left is a folder selection which defaults to C:\Program Files\Bentley\Engineering\RAM Elements\ComboGenerators\. in the main module the program will list each file with a .rag extension for selection. These *.rag files are plain text files with simple code to express how load combinations should be generated using constants, Boolean operators (AND, OR), and load types.

For full details on the .rag file format refer to the program help, by pressing F1 while this dialog is open.

See Also

For information on load combinations for Connection Design see Ram Connection Capabilities and Modeling

[[Ram Elements - Tension Only Members]]

(UNDER CONSTRUCTION)

1.    What Does the iTwin Mean for Engineers?

Engineers invest significant time building data rich 3D models for analysis and design. While the level of detail put into these models varies based on project complexity and objectives, they are nonetheless useful beyond a single engineer’s computer. Unfortunately, though, they are often used only for analysis and then discarded, or visited again only when absolutely needed. What if each engineering analysis model you develop could be used for collaboration, review, and exchange during the entire course of the project and beyond? This is the spirit of Bentley iTwins.

In November 2020, Bentley’s Engineering Simulation software products (STAAD, SACS, AutoPIPE, RAM) started to be integrated with Bentley iTwin Services. This will allow users to do more with the models they build in these applications without any disruption to the way the software is currently used. Further, this value will grow significantly over time. The most visible and immediate change you will notice in the software applications is a new add-in called iTwin Services. This will be presented as an in-product sidebar and common to all Engineering Simulation products that interact with the iTwin. This add-in will ‘house’ all the iTwin-enabled capabilities these applications offer.

Figure 1 - iTwin Services, available as in-product sidebar within any Engineering Simulation products that interacts with iTwin Services.

The in-product sidebar can be launched via the iTwin Services button in the ribbon or file menu (see Table 1). All Engineering Simulation software products expose the launching of the in-product sidebar via iTwin Services button.

Table 1 - iTwin Services button in Engineering Simulation products

There will be multiple categories of functionality eventually offered under iTwins Services. The first is iTwin Design Review. This service allows a model created in an analytical desktop application to be converted into a point of collaboration hosted in the web that can be shared with any team member or stakeholder on a project. Details on this service now follow.

Figure 2 - iTwin Design Review, select the highlighted option (Design Review) within the sidebar to get started

2.    iTwin Design Review

Bentley iTwin Design Review is a collaborative service hosted on the web that allows two or more interested parties to communicate with one another in the context of a 3D model or, more accurately, an iTwin.

The iTwin Services Add-in within the desktop application publishes the analysis model to an iTwin Design Review session, and therefore into an intuitive point of collaboration that facilitates review of design work in progress (see Figure 3).

Figure 3 - A model as presented in-product (STAAD) and corresponding iTwin Design Review session in the browser with coordination discussion.

The web-based interface (accessible with a web browser) of Design Review offers a set of commands for navigating, viewing from different perspectives, isolating key elements, and clipping views.

Several review tools are included with the service:

• Measurements, including distance, area, location, radius, and angle
• Querying elements for physical information, such as dimensions, construction materials, and coordinates
• Querying analytical information, such as member fixities, applied loads, and reactions

Figure 4 - Commands in Design Review for measurement and view control

Practical Applications of iTwin Design Review

Many aspects of iTwin Design Review are particularly relevant to engineering analysis workflows. Project managers or other stakeholders in a project may not be skilled in, or have access to, the analytical software used by engineers to analyze and design a structure. These individuals may instead have a practice of reviewing a set of 2D drawings or a BIM model that is disconnected from the engineering analysis models. In this case, the reviewer may not have a complete understanding of the assumptions used by the designers. iTwin Design Review can therefore help project managers catch incorrect assumptions or errors during the design phase before it becomes a construction problem.

Some of the practical applications of this technology to the traditional engineering review and collaboration process include:

• Have a conversation with participants via chat in the context of a 3D model, annotating and marking up objects, and leaving questions, comments, and markups for specific stakeholders.
• Include stakeholders, such as project managers and other engineering disciplines, that are not users of Engineering Simulation software, in this review process. All that is needed is a web browser and anyone invited can contribute to the review.
• Resolve issues raised by team members directly in the desktop application.
• Save a record of conversations (chats) in the review so that reasons for key decisions can be revisited at a later point if needed.
• Create specific views of the structure, with objects of interest isolated and zoomed to, that collaborators and reviewers can see immediately without needing to recreate the view themselves.

Getting Started with iTwin Design Review

Coming soon.

iTwin for Engineering Analysis and Design

1.    Introducing the iTwin for Engineering Analysis and Design

Engineers invest significant time building data rich 3D models for analysis and design. While the level of detail put into these models varies based on project complexity and objectives, they are nonetheless useful beyond a single engineer’s computer. Unfortunately, though, they are often used only for analysis and then discarded, or visited again only when absolutely needed. What if each engineering analysis model you develop could be used for collaboration, review, and exchange during the entire course of the project and beyond? This is the spirit of Bentley iTwins.

In November 2020, Bentley’s Engineering Simulation software products (STAAD, SACS, AutoPIPE, RAM) started to be integrated with Bentley iTwin Services. This will allow users to do more with the models they build in these applications without any disruption to the way the software is currently used. Further, this value will grow significantly over time. The most visible and immediate change you will notice in the software applications is a new add-in called iTwin Services. This will be presented as an in-product sidebar and common to all Engineering Simulation products that interact with the iTwin. This add-in will ‘house’ all the iTwin-enabled capabilities these applications offer.

Figure 1 - iTwin Services, available as in-product sidebar within any Engineering Simulation products that interacts with iTwin Services.

The in-product sidebar can be launched via the iTwin Services button in the ribbon or file menu (see Table 1). All Engineering Simulation software products expose the launching of the in-product sidebar via iTwin Services button.

Table 1 - iTwin Services button in Engineering Simulation products

Product	iTwin Services
STAAD.Pro Physical Modeler
RAM Structural System
RAM Elements
AutoPipe
SACs

There will be multiple categories of functionality eventually offered under iTwins Services. The first is iTwin Design Review. This service allows a model created in an analytical desktop application to be converted into a point of collaboration hosted in the web that can be shared with any team member or stakeholder on a project. Details on this service now follow.

Figure 2 - iTwin Design Review, select the highlighted option (Design Review) within the sidebar to get started

2.    iTwin Design Review

Bentley iTwin Design Review is a collaborative service hosted on the web that allows two or more interested parties to communicate with one another in the context of a 3D model or, more accurately, an iTwin.

The iTwin Services Add-in within the desktop application publishes the analysis model to an iTwin Design Review session, and therefore into an intuitive point of collaboration that facilitates review of design work in progress (see Figure 3).

Figure 3 - A model as presented in-product (STAAD) and corresponding iTwin Design Review session in the browser with coordination discussion.

The web-based interface (accessible with a web browser) of Design Review offers a set of commands for navigating, viewing from different perspectives, isolating key elements, and clipping views.

Several review tools are included with the service:

• Measurements, including distance, area, location, radius, and angle
• Querying elements for physical information, such as dimensions, construction materials, and coordinates
• Querying analytical information, such as member fixities, applied loads, and reactions

Figure 4 - Commands in Design Review for measurement and view control

In addition to review tools, iTwin Design Review crucially offers the ability to review and comment with your participants at points of interest in the model. Comment threads can be assigned statuses (Resolved, Open etc.) and Disciplines. Discussions can be directed specifically at a participant using @mentions. Just type @ before their name and select from the menu that appears. They receive a notification with a link, which they can go directly to the point in the conversation where they were mentioned.

2.1       Application of iTwin Design Review to Engineering Analysis and Design

Many aspects of iTwin Design Review are particularly relevant to engineering analysis workflows. Project managers or other stakeholders in a project may not be skilled in, or have access to, the analytical software used by engineers to analyze and design a structure. These individuals may instead have a practice of reviewing a set of 2D drawings or a BIM model that is disconnected from the engineering analysis models. In this case, the reviewer may not have a complete understanding of the assumptions used by the designers. iTwin Design Review can therefore help project managers catch incorrect assumptions or errors during the design phase before it becomes a construction problem.

Some of the practical applications of this technology to the traditional engineering review and collaboration process include:

• Have a conversation with participants via chat in the context of a 3D model, annotating and marking up objects, and leaving questions, comments, and markups for specific stakeholders.
• Include stakeholders, such as project managers and other engineering disciplines, that are not users of Engineering Simulation software, in this review process. All that is needed is a web browser and anyone invited can contribute to the review.
• Resolve issues raised by team members directly in the desktop application.
• Save a record of conversations (chats) in the review so that reasons for key decisions can be revisited at a later point if needed.
• Create specific views of the structure, with objects of interest isolated and zoomed to, that collaborators and reviewers can see immediately without needing to recreate the view themselves.

2.2       Getting Started with iTwin Design Review

2.2.1    Access iTwin Design Review in-product

1. Click the iTwin Services button in your product. See Table 1 for its relative location in your product.

2. After which the iTwin Services sidebar would present itself (see Figure 1). Select Design Review within the services offered under iTwin Services (as presented in the sidebar).

Figure 5 - Select Design Review under iTwin Services

3. The default web browser may appear and you will be prompted to sign-in using your CONNECT credentials and grant the necessary rights. Once acknowledged, the access token is saved on your machine for 30 days (eliminating the need to sign in again during this time).

Figure 6 - Application requests access. Click Allow to grant the necessary rights to proceed.

Figure 7 - iTwin Design Review authentication splash screen and subsequent loading page. Click Home to return to iTwin Services page.

2.2.2    iTwin Design Review Main User Interface Overview

Once the access token is granted and completed loading, the main iTwin Design Review page is shown and is divided into 4 sections as shown below.

Figure 8 – iTwin Design Review Main User Interface Overview

Header: Displays currently logged in user as well as the iTwin Design Review logo (clicking the logo would take you back to the initial splash screen).

New Session: Click on New Session to launch New Session form. This is the first step to prepare the conversion of your model to an iTwin Design Review Session (see 2.2.3          Creating a New Session).

Previous Session: Displays a thumbnail of the last iTwin Design Review Session that you have accessed in the web browser. Click Open Last session to view iTwin Design Review Session in your default browser. Note that this is provided for information but may be related to a completely different model or project.

Sessions List: Displays a flat list of your iTwin Design Review sessions. The Session List view can be searched and filtered by tags. Tags are added during iTwin Design Review session creation process. The sessions list would initially be prefiltered to your current file Tag (usually the currently opened file name). This is so that the sessions list would be most relevant to your currently opened file. Remove the session Tag by clicking the “x” next to the filtered tags to view all you design review sessions.

Click to access sessions filter dropdown – this allows you to further filter on currently active file tag or to toggle between filtering on Open vs Closed Sessions. Sessions that you create are by default Open, so that it can be interacted on. Sessions that are no longer relevant can be optionally “Closed” to not clutter your sessions list.

Each iTwin Design Review Session (see Figure 9) is shown as a list item in the Sessions List.

Figure 9 - A iTwin Design Review session list item with legend key

A: Displays the iTwin Design Review Session Name along with the status of the session. Click on the Session Name to open the session in the default browser. Chrome, Firefox or the new Edge browser (based on Chromium) is recommended for the best design review experience.

          Indicates that the session is currently being converted online.

          Indicates the session is ready to be accessed.

          Indicates there was an error in the session creation process.

B: Supplementary information regarding the session.

         Indicates the number of comments for this session. A mouse hover over this icon would show the comment subject titles in this session.

         Indicates the creation date of this session. Hovering of this icon would reveal a more detailed timestamp.

        Shows the assigned Tag(s) to this session. Clicking any of the Tag(s) would filter all sessions to the selected Tag.

C: Displays the user initials of participants of this session. Hovering over each initial would reveal the full name of participants.  Clicking the “+” icon allows you to Add or Remove participants (see Figure 10). Auto suggested list of participants (from your organization) would display as you type into the Add Participants field. You can also add external participants to your design review session.

Figure 10 - Edit Session Participants Dialogue

D: Displays when the session was last modified (relative to the current date/time).

E: Thumbnail of the session. When you first create a session, this would be a blank placeholder. The thumbnail of the design review session is automatically retrieved from the view extracted from the first comment entered in the iTwin Design Review session.

F: More Actions. (see Figure 11)

Figure 11 - Session List Item- More Actions.

Launch Session: Will navigate to the iTwin Design Review session with your default browser. This is an alternative method to access to the iTwin Design Review session to directly clicking the underlined session name.

Edit Tags: Present you with the opportunity to edit the tags assign to the session

Export Comments: Exports all comments from the design review session to a temporary XLS file. Your default XLS viewer would then automatically open this downloaded file (usually Microsoft Excel). To keep a local copy for your reference, perform a “Save-As” action within Microsoft Excel.

Close Session: Click Close to Close the Session. A Closed Session can no longer be commented on and won’t appear in the sessions list unless Close Session visibility is toggled on.

2.2.3    Creating a New Session

Click “Create Session” in New Session block (Figure 8) to launch Create New Session form.

For below steps Refer to Figure 12 for the elements on Create New Session form.

Figure 12 - Create new session form

Step 1: Session Name - The name of the session will be suggested based on the name of the model. However, note that this should be unique (amongst All Open Sessions) and as such if a session has been initiated with the name of the model already, then an alternative name should be provided.

Step 2: Define any tags. (Optional)The name of the model is provided as a suggested tag, but any others can be added to help in getting collections of sessions at a later stage.

Step 3: Session Participants - (Optional) Define additional participants. Clearly the power and benefit of a design review session comes from the collaborative effort of working with colleagues. They can be identified at this time or any time later once the session has been initiated.

Step 4: Session Settings – (Optional) Product specific settings on HOW a session is to be created (e.g include loads, rebars, etc..).

Step 5: Next – Clicking ‘Next’ will then start the process of building the Design Review model from your model and push it into the iTwin Design Review service. The desktop conversion process may take a few minute to process, once the desktop conversion has completed you will be informed of this via an info message (Figure 13). At this stage, the process is purely online, therefore you can continue to work in your product while the conversion takes place online. Your session is “ready” when you see an info message per (Figure 14) or a green tick  next to your session list item

Figure 13 - Successful upload message

Figure 14 - Successfully created session message - with hyperlink to the created review session

Once completed, the Session is marked with a tick and by clicking on the session, the iTwin Design Review session would launch in your default web browser where discussions and feedback can be solicited from your Session Participants (i.e Design Team/Project Members). The session is now ready to add one or more comments which can become discussion threads with others in the design team that can be used to assist in progressing the project.  

Figure 15 - A Successfully created session with a ready status green check mark next to session name. Click directly on the Session Name to launch Design Review in the default web browser.

Additionally, note that notification that the design review session is ready will be reported in Connection Client and/or Email.

Figure 16 - Connection Client Notification

Figure 17 - Design Review Session is Ready email message as presented in Microsoft Outlook

Your invited participants would similarly be notified through Connection Client and email message (Figure 18).

Figure 18 - Collaboration request email automatically sent by iTwin Design Review to all Session Participants.

Figure 19 - iTwin Design Review session in the web browser

Figure 20 –Comment and markup of proposed solution in an iTwin Design Review session in the web browser.

Figure 21 - Comment reflected within Product itself (info tip when hovered over comment icon)

For a general guide on the iTwin Design Review service, see:- https://communities.bentley.com/products/digital-twin-cloud-services/itwin-services/w/itwin-design-review-wiki

Using RAM Connection from within STAAD.Pro CONNECT Edition:

Help Documentation related to the Connection Design is available within the STAAD.Pro CE Help as shown below

Ensure that STEEL material is assigned to all members for which connection design is required. Any vertical braces should be assigned with the TRUSS attribute from the Bean Tools ribbon tab.

Analyze the STAAD.Pro model.

Launch RAM Connection using the Connection Design workflow as shown next

Click on the Load Envelope icon shown next to select the load cases or combinations for connection design

The Design Load Envelope dialog box would pop up.

Check the appropriate load cases or combinations

Click on OK

As outlined in the picture below, from the ribbon menu choose “Select Joints” and choose a specific joint type type, for example you may use Select Joints – “Select all beam-column flange joints” to select all the intersecting beam to column flange connections in the model.

Alternatively, you may use the beams cursor to select a single beam and supporting column, or you may select multiple nodes where you intend to apply the same type of connection.

Once the required entities are selected (beams or nodes), choose the Smart Connection menu option as shown next

“Smart Connections” are those where the most variables are selected by the program. Basic connections are those where more of the data is specified by the user (via the basic connection templates) and the program only selects a few aspects of the design. Gusset connections are smart connections involving a vertical brace. They are valid for a connection of a beam and a brace to a column, or a pair of braces to a beam (i.e. a chevron connection) for example.

The following dialog box will appear

Select the design code for connection design at the top; this must be consistent with the load envelopes previously selected to get the correct design.

Then, select the type of connection from the drop down list in the middle. The descriptions are pretty clear, but refer back to the RAM Connection documentation when a connection type or abbreviation is unknown.

Pick one or more specific connections from the left box and click the arrow to the right and then OK to assign the best connection to the selected joints. The Connection will now be applied and a Validation window will appear confirming that connection has been assigned.

When no selected connection works or fits for the selected joint there will be a warning. Otherwise a new connection will appear on screen (as a grey triangle typically) and also in the table of connections in the upper right.

You can review the specifics of a connection by double clicking the triangle while using the Select Joints Cursor, or by double clicking in the table on the row for the specific connection you want to review.

The window that pops up is identical to the Connection Pad seen in Ram Connection Standalone.

Here is where you can alter parameters of the connection like the weld sizes, bolt types etc. Changes to the member sizes, orientation or loads can also be made in this view for investigation, but those changes cannot be saved since they are always read in from the Main STAAD.Pro file. Changes to the materials, section sizes, geometry etc. should always be made in the main STAAD.pro file.

Use the Results button in the picture above to review the design report. Use the DXF View in the picture above to see the connection as a flat line drawing (this is also where a dxf file of the connection can be exported).

Alternately the tab labeled “Results” in the picture below can also be used to review the dxf drawings and design reports for the tabulated connections.

If you need to make changes and reanalyze the model, the connection design can be re-checked later without losing any of the connections or any customizations made to those (so long as the model changes to not invalidate the original connection).

Using RAM Connection from within STAAD.Pro v8i :

The documentation from within STAAD.Pro is available under Help – Contents as shown below

Be aware that this includes the original documentation from STAAD.pro 2006 and some things have been improved or streamlined since then.

We recommend that you start with a simple model that includes at least a pair of columns and a beam, or one of the completed steel examples, like Examp01.std.

Be sure to assign a STEEL material to all of the members you plan to design connections for. Furthermore, any vertical braces should be assigned as TRUSS member types.

Analyze the model and launch RAM Connection design using the tab along the top as shown next

From the Connection Design menu, select “Load Envelope for Connection” (or the first square button in the middle of the screen):

Check one or more loads cases or combinations that you want the connections to be designed for.

From the Connection Design menu now select the “Assign Ram Material” command (or use the 6^th square button in the middle of the screen):

To avoid getting warnings, assign a value for Fu, Ry and Rt for all materials in the STAAD.pro file and Click OK. This needs to be done once for each STAAD file.

Now use the Select menu to “Select Joints” of a specific type, for example use Select Joints – “Select all beam-column flange joints” to select all the intersecting beam to column strong axis locations in the model. Conversely, you can use the beams cursor to select a single beam and supporting column, or you can select the entire model, all joints, but this can be slower when assigning connections.

Next Assign the desired type of connection. To summarize,“Smart Connections” are those where the most variables are selected by the program. Basic connections are those where more of the data is specified by the user (via the basic connection templates) and the program only selects a few aspects of the design. Using Basic connections effectively generally requires some up-front work to customize the connection templates. Additional information
about that is available upon request. Gusset connections are smart connections involving a vertical brace. They are valid for a connection of a beam and a brace to a column, or a pair of braces to a beam (i.e. a chevron connection),
for example.

To assign a Smart Connection use the Connection design menu – “Assign Smart Connections" or the “S” button in the middle:

In the window that appears, select the design code for connection design at the top; this must be consistent with the load envelopes previously selected to get the correct design.

Then, select the type of connection from the drop down list in the middle. The descriptions are pretty clear, but refer back to the RAM Connection documentation when a connection type or abbreviation is unknown.

Pick one or more specific connections from the left box and click the arrow to the right and then OK to assign the best connection to the selected joints. When no selected connection works or fits for the selected joint there will be a warning. Otherwise a new connection will appear on screen (as a grey triangle typically) and also in the table of connections in the upper right. You can review the specifics of a connection by double clicking the triangle while using the Select Joints Cursor, or by double clicking in the table on the row for the specific connection you want to review.

The window that pops up is identical to the Connection Pad seen in Ram Connection Standalone.

Here is where you can alter parameters of the connection like the weld sizes, bolt types etc. Changes to the member sizes, orientation, or loads can also be made in this view for investigation, but those changes cannot be saved since they are always read in from the Main STAAD.pro file. Changes to the materials, section sizes, geometry or forces should always be made in the main STAAD.pro file.

Use the Results button to review the design report. Use the DXF View to see the connection as a flat line drawing (this is also where a dxf file of the connection can be exported). The left hand tab labeled “Drawing & Result” can also be used to review the dxf drawings and design reports for the tabulated connections.

Once you have the connection design the way you like it, click Save and Close. If you need to make changes and reanalyze the model, the connection design can be re-checked later without losing those changes (so long as the model changes to not invalidate the original connection).

See Also

RAM Connection Capabilities and Modeling FAQ

How to Customize a RAM Connection Template in STAAD.Pro

Structural Product TechNotes And FAQs

Problem Description

For a wide flange section having top and/or bottom cover plates, the elastic section
moduli Sy & Sz about Y & Z axes respectively, are calculated incorrectly when used with the AISC ASD (9th Edition) code. The effect of this is an overestimation of the section bending capacities which may result in an unconservative design.

The issue will be observed when all of the following conditions exist:
1) The member is designed to the AISC ASD (9th Edition)
2) The member is assigned with a wide flange profile that has additional cover plate(s)
3) The member is subject to forces that cause major and/or minor axis bending moments

The error does not occur when wide flange sections without cover plates are used for design by AISC ASD (9th Edition) code but occurs only when the wide flange sections with “top and/or bottom cover
plates” are designed. Note that the error is more pronounced when using sections with larger cover plates.

Workaround

No workaround is available as of now for this defect.

. 

Solution

The defect is already addressed and a fix is available in STAAD.Pro CONNECT Edition V22 Update 5 (22.05.00.131).

RAM Structural System CONNECT Edition Version 17.02 SES Release Notes

Anticipated Release Date: January 2021

This document contains important information regarding changes to the RAM Structural System. It is important that all users are aware of these changes. Please distribute these Release Notes and make them available to all users of the RAM Structural System.

Installation Instructions:

If you have enabled the CONNECTION Client you will automatically be notified of the newest version and will be able to update through that service by simply selecting the update command. Otherwise, this version can be found on the Bentley Software Fulfilment web page by logging into CONNECT Center and selecting the Software Downloads icon. Search for “RAM Structural System” and select the latest version.

Important Notices:

This version automatically converts databases created in previous versions to the new database format. Note that a backup file is created automatically when a database is converted; the name of the database is the same, with “Orig” and the version number appended to the name. The file has an extension of “.zip” and is located in the same directory as the original database.

The previous steel tables and load combination templates supplied with the program will be replaced with new tables and templates of the same name. If you have customized any Master or Design tables or load combination templates supplied with the program without changing the file names, those file names should be renamed from the original RAM table names prior to installation to prevent your changes from being lost.

Tutorial:

Except for minor corrections, the Tutorial Manual has not been updated but is still valid. The appearance of some parts of the program in this version may differ from that shown in the Tutorial.

Bentley CONNECT and Product Licensing FAQ:

Appendix A at the end of these Notes contains important information on the features and capabilities provided to you through Bentley CONNECT, and for important information on configuring Bentley CONNECT Licensing. These were first implemented in RAM Structural System v16.00. If you have not already done so, you are urged to configure your licensing thresholds so that warnings are given if you are attempting to launch the program that would result in an overuse.

Appendix B at the end of these Notes contains a description of features available in the RAM Structural System to help prevent inadvertent use of unlicensed modules. Refer to that document for more information. Note that with CONNECT Licensing, warning messages are given in the event there is no license available, so it generally isn’t necessary now to block modules using that feature. Note: At some point in the future this feature will be removed since it is redundant. To provide protection against inadvertent overuse of licenses, license threshold limits should be set as explained in Appendix A.

Beginning with RAM Structural System V17.00 the licensing was changed; the licenses on the individual modules (e.g., RAM Steel, RAM Concrete, RAM Frame, RAM Foundation) were consolidated into a single package, RAM Structural System. See Appendix C at the end of these Notes for more information on this license consolidation.

Security Risk Advisory:

Not applicable to this release. Every effort is made to ensure that there are no security risks in the software. There are no known security issues, no issues were addressed in this version.

New Features and Enhancements:

For details on these new features and enhancements, refer to the manual .pdf files available from the Help menu in each module or from the Manuals folder on your hard drive.

Simpson Strong-Tie Yield-Link Moment Frame Connection

The requirements for the analysis and design of the Yield-Link moment frame connection have been comprehensively implemented, with close coordination with the engineers at Simpson Strong-Tie. The connection is assigned using the Assign – Beams – Frame Beam Connection Types command. The influence of the connection on the joint and frame stiffness is automatically determined and applied in the analysis. The requirements of AISC 360-10 and AISC 360-16 have been implemented for the basic steel design checks, and the requirements of AISC 341-10 and AISC 341-16 have been implemented for the seismic design checks of the connection, columns, and beams. Pertinent panel zone shear check and strong column – weak beam requirements from AISC 358 are also implemented.

Crash Reporting

In order to improve the stability and reliability of the program we have implemented a feature in which a report is delivered to Bentley anytime the RAM Structural System program crashes. When a crash occurs, a dialog is given requesting a description of the events leading to the error. Please provide us with as much pertinent information as you can (what series of events that you did prior to the crash, etc.), and then select the command to Send Error Report. This will assist us in locating the cause of program crashes, and better enable us to eliminate their causes.

Verification of File Integrity on Save

When Save is invoked, a check is now made on the integrity of the saved file. If it appears that key portions of the database have failed to save (due to, for example, a system disruption during the Save), a second attempt will be made to save the file; if there appears to still be an error, an attempt will be made to create a backup of the original database (in the state it was at the last Save, it won’t contain any of the recent changes made since the last Save), and a Warning message is given notifying the user that there was problem with the Save. It is possible that the database files that would still be in the Working directory are correct, and the user is advised to copy those to another directory before closing the Warning message and the program. The user can then attempt to open the model by navigating to the directory to which the database files were copied. Note that this is intended to prevent an exceptionally rare problem of unknown cause, but one which resulted in corruption and loss of the model. It is believed that this new workflow will prevent the loss of the model. Please report to Technical Support when this message is given so that we can attempt to determine the cause.

IBC Storage Live Load Reduction on Beams

IBC 2018 Section 1607.11.1.2 and Section 1607.11.2.1 allow Storage live loads to be reduced up to 20% if the member supports load from two or more levels. This was previously implemented for columns, but not for beams, such as transfer girders, that support load from two or more levels. Storage Live Load reduction per the IBC has now been implemented for beams that support load from two or more levels, allowing of a reduction of up to 20%.

IBC Alternate Live Load Reduction Method

The IBC includes both a basic Live Load Reduction method (Section 1607.11.1) and an alternate Live Load Reduction method (Section 1607.11.2). Beginning with IBC 2015 a subtle but important change was made to the Alternate method: previous to IBC 2015 the requirement stated that the reduction for horizontal members (i.e., beams) is limited to 40% and the reduction for vertical members (i.e., columns) is limited to 60%. Note that this meant that a column carrying load from only one level could be reduced up to 60%, and a transfer girder carrying load from more than one level could only be reduced up to 40%. Beginning with IBC 2015 the requirements now say that for members receiving load from one level only the reduction is limited to 40% and for members receiving load from two or more levels the reduction is limited to 60%. In prior versions of the program the requirements of the pre-IBC 2015 were implemented but beginning with this version the requirements given in IBC 2015 and later are now used.

Detailing Values in Master Steel Tables

Previously the Master Steel Tables only contained the design section dimensions and properties, not the detailing section dimensions because those detailing values were not used by the program. The new Yield-Link feature now uses some of these values, so the Master Table format has been enhanced to include these values:

       Depth_det  Tw_det  Bftop_det  Bfbot_det  Tftop_det  Tfbot_det  ktop_det  kbot_det  k1top_det  k1bot_det  T_det

These detailing values have been added to the RAMAISC Master tables provided with the program. At this time they have not been added to any of the other Master tables provided by the program, but the user can edit those tables to include those values if desired. See Section 8.4 of the RAM Manager Manual for a complete description of the new data format.

Note that existing models will not automatically use these revised tables. In order to update the tables used by a model, invoke the Criteria – Master Steel Table command in the RAM Manager, and follow the instructions given there.

If it is desired to use user-created Master tables with the Yield-Link feature it will be necessary to add the detailing values to those tables.

Updated Table of Decks – US

The ramdecks.dck file, the file that contains the composite decks used in the United States, has been updated based on the latest deck data made available by the deck manufacturers. The Wheeling decks were removed since that deck is no longer produced, and New Millennium decks were added. The values for Ybar (which only impacts the design of beams using the old ASD 9th Edition code) were slightly modified for ASC 3W and Vulcraft 1.5VL. The depth was changed from 2" to 2.0625" for Verco W2 Formlok, which also changed AcRib and Ybar (which will slightly impact designs, including loads from deck self-weight).

New models will use the updated values, existing models will continue to use the previous values. If it is desired to update the tables used by an existing model, invoke the Criteria – Design Steel Tables command in the RAM Manager, and follow the prompts given there.

Updated LH Joist Tables and 2.5K Joists

In the Steel Joist Institute’s recently released 45^th Edition K-Series, LH-Series, DLH-Series, Joist Girders Standard Specifications Load Tables and Weight Tables for Steel Joists and Joist Girders Catalog, the load tables for the LH-series joists have been updated. The joist series has been expanded to include several new LH joist sizes, and the range of spans listed for each joist has been increased. In many cases the allowable loads have been increased. The RAMSJILH.JST and RAMSJI.JST tables have been updated to include these changes.

The SJI Catalog also includes 2.5K joist substitutes, a series of 2.5” deep members intended for spans of 10 ft. or less. These joist substitute members have been added to the RAMSJIK.JST and RAMSJI.JST tables.

Steel Joist Camber

In the Steel Joist Institute 45^th Edition K-Series, LH-Series, DLH-Series, Joist Girders Standard Specifications Load Tables and Weight Tables for Steel Joists and Joist Girders Catalog, the standard joist camber is given in Table 4.6-1. When joists are fabricated, they are fabricated with the camber given in that table unless otherwise specified by the engineer. Typically, joists are designed for strength based on the Total Load, and for deflection based on the Live Load (typically L/360). It is not an SJI requirement to assign deflection limits on Dead Load or on Total Load, and the joist tables in the joist manual are based only on a deflection limit of L/360 on the Live Load. Because it would be fairly rare to specify a deflection limit on Total Load, the program for simplicity did not consider camber when checking a deflection limit on Total Load. This has now been enhanced. The Standard Joist Selection report now lists the standard SJI camber, and lists both the Total Load deflection and the Net Total Load deflection (which is the Total Load Deflection minus the camber). In the selection of the joist, if there is a Total Load deflection limit set by the user, the program compares that limit with the Net Total Load deflection. The Deflection Summary report also now lists the Net Total Load deflection and the camber.

Ground Level for Wind

In RAM Frame the Ground Level is assumed by default to be at a level below the lowest Story. However, the user has the ability to specify any level as the Ground Level, for example when a structure has a basement. Not only does this impact the lateral constraints for the analysis of levels at and below the Ground Level, it also impacts the generation of the wind loads. The program now allows the Ground Level for wind loads to be specified independently of the Ground Level for analysis.

Eurocode Seismic Forces

In RAM Frame seismic loads per Eurocode EN 1998-1:2004 + A1:2013 can now be generated. It is based on Section 4.3.3.2 Lateral Force Method of Analysis. The Eurocode dynamic response spectra analysis can also be performed. Both methods have the option to include the accidental torsional effects defined in Section 4.3.2.

Diaphragm Section Cuts Enhancement

The Diaphragm Forces report has been enhanced. Previously the report had a section that listed the combined Diaphragm and Frame Member Forces. That section of the report is still included, but when a section cut crosses one or more beams there is a new section of the report that lists the Diaphragm Only Forces. This makes it easier to identify the forces in the diaphragm itself.

The report has been expanded to also now show the force values at discrete points along the section cut.

Vertical Modal Response

When the option to Include nodal mass in Z-direction in the Criteria – General command is selected in RAM Frame, and the diaphragms have been specified as Semirigid, the Periods and Modes report has been modified: Z-direction (vertical) values have been added to Modal Participation Factors, Modal Direction Factors, and Modal Effective Mass Factors.

DuraFuse Option for Rigid Panel

For the DuraFuse moment frame connection there is now an option to specify the Panel Zone Stiffness to be considered rigid in the analysis (rather than using the Calculated Spring Stiffness). Contact DuraFuse Frames, LLC, for information on when it is appropriate to assume that the panel is rigid.

Stress Display in Concrete Wall

In the option to display stress contours (the Mesh Options button in the View/Update command in the Concrete Wall module), options to show the contours for SVMax, SavgMax, and S Von Misses have been added. Options have also been added to show the stresses on the Primary Face versus the Secondary Face.

Data Extractor

The Data Extractor is invoked using the Post-Processing – Extract Data command; it provides a powerful means of extracting model, design, and analysis results data. Several improvements have been made, both in this version and in version V17.01 but were not documented. It has been enhanced to extract additional data. For more information, see Appendix D RAM Data Extractor in the RAM Manager Manual.

The following new fields have been added to existing tables in the Geometry category:

• ColumnData table:
  • Size
  • Depth
  • Width
  • StoryHeight
  • Grid_Label
  • Several values associated with the DuraFuse connection

• BeamData table:
  • LeftOfBeam (condition at left: Beam, Edge, or Opening)
  • RightOfBeam
  • DistanceToLeft (distance to adjacent beam, edge, or opening; -1.0 indicates that there is no deck on the beam)
  • DistanceToRight
  • Size
  • CantLeftLength
  • MidSpanLength
  • CantRightLength
  • Some values associated with the DuraFuse connection

• BraceData table:
  • Length

The following new fields have been added to an existing table in the Criteria category:

• RAMManagerCriteria table:
  • Model_Name
  • Export_Time_Stamp (the time at which the data was extracted)

Several new tables have been added to the Geometry category:

• DeckData
• DeckProp_Comp
• DeckProp_NonComp
• DeckProp_Conc
• JointData

A new table has been added to the Criteria category:

• SteelBeamJoistCriteria

Several new tables have been added to the Loads category.:

• LoadCombosData
• GravLoadReactionsOnBeams
• GravLoadReactionsOnColumns
• GravLoadReactionsOnWalls
• LnLoadTakeDownOnWalls
• PtLoadTakeDownOnWalls

ISM – Typical Layout Types

Previously if a model used a layout type on more than one story it was necessary to modify the model such that each story had its own layout type before the model could be exported to ISM. That is no longer necessary; a model in which a layout type is used on two or more stories can be exported to ISM, and the relationship of the stories and layout types will be preserved.

Technology Preview Features:

Technology Preview features are features that are still under development, and have not been completely certified. They are made available because they may offer significant benefits to the user, even in their current state. If you use these features, please provide feedback so that we can refine the features.

DataCheck

In the Modeler, the Integrity – DataCheck command has been enhanced to include additional checks:

• Members slightly offset from grids. If a member is very nearly but not exactly attached to a nearby grid intersection, it is often an indication that the member is not attached to the intended snap point, but rather to a nearby point. This is generally not a problem, such conditions are allowed, but when the other framing around this member use the correct grid point, in very rare cases this condition can cause gravity loads to be incorrectly distributed or cause the analysis to terminate.
• Members very nearly horizontal or vertical. If a beam or wall is very nearly but not exactly horizontal in plan, it is often an indication that the member end is not attached to the intended snap point, but rather to a nearby point. Same for a member that is very nearly but not exactly vertical in plan. This is generally not a problem, such conditions are allowed, and in some cases intended, but when the other framing around this member use the correct snap point, in very rare cases this condition can cause gravity loads to be incorrectly distributed or cause the analysis to terminate.
• Deck or Load polygon edges misaligned with member. If the edge of a Deck or Surface Load polygon very nearly but not exactly coincides with a beam or wall, it is often an indication that the polygon vertex was not attached to the intended snap point, but rather to a nearby snap point. Alternatively, it may be an indication that the beam or wall was not modeled exactly as intended. Deck polygon edges should coincide precisely with beams and walls; surface load polygons are not required to coincide with beams and walls, but this condition, in which the edge very slightly diverges from the beam or wall, should be avoided. The program generally deals with this problem correctly, but in rare cases this condition can cause composite properties to be incorrectly assigned to a beam, cause gravity loads to be incorrectly distributed, or cause the analysis to terminate.

If any of these warnings are given it is recommended that the model be modified to eliminate the condition, or that the engineer carefully inspect the resulting designs to verify that properties and loads were properly and correctly assigned and distributed, not only to the member referenced, but to surrounding members as well.

These conditions are rare when the model has been created in the Modeler, but are more prevalent when the model has been imported from Revit, which does a poor job of enforcing modeling precision unless great care and effort is taken there by the person creating that model.

Note that that because these new checks are still Technology Preview features, these new checks are not included in the checks performed by the Datacheck by default. See Appendix D at the end of this document for instructions on setting up the program to include these checks when the Datacheck is invoked.

Error Corrections:

Some program errors have been corrected for this version. Corrections made to graphics, reports, Modeler functions, program crashes, etc., that were considered minor are not listed here. The noteworthy error corrections are listed here in order to notify you that they have been corrected or to assist you in determining the impact of those errors on previous designs. These errors were generally obscure and uncommon, affecting only a very small percentage of models, or had no impact on the results. The errors, when they occurred, were generally quite obvious. However, if there is any question, it may be advisable to reanalyze previous models to determine the impact, if any. In each case the error only occurred for the precise conditions indicated. Those errors that may have resulted in un-conservative designs are shown with an asterisk. We know these errors are disruptive, we apologize for any inconvenience this may cause.

Manager

SNOW VS ROOF LIVE LOAD*: In the Criteria – Member Loads command, if the selection for Snow vs Roof Live Load was Consider Roof Live Loads, Ignore Snow Loads, and the Code for Live Load Reduction selection was changed to NBC of Canada, BS 6399, Eurocode, Eurocode UK NA, AS/NZS, China, or Hong Kong, the selection for Snow vs Roof Live Load changed to Consider Snow Loads, Ignore Roof Live Loads.

Effect: If the Code for Live Load Reduction selection was changed to any of the codes listed, the selection for Snow vs Roof Live Load may have unintentionally switched to Consider Snow, Ignore Roof Live Load, resulting in Roof Live Loads being ignored in analysis and design.

Modeler

FRAME COLUMNS ON GRAVITY WALLS: If the end of a Gravity wall shared the same point as a Frame column, and a Frame column above was supported by that Frame column, a DataCheck warning was erroneously being displayed indicating that a Frame column was supported by a gravity member (referring to the Gravity wall). The warning should not have been displayed since there was also a Frame column at that location.

Effect: Erroneous DataCheck warning for an acceptable configuration.

Steel Beam

WEB OPENING TEE BUCKLING CAPACITY CHECK: In the design of beams with web openings per AISC Design Guide #2, it is not required to perform the buckling capacity check of tees with an aspect ratio less than 4.0. However, the program incorrectly and unnecessarily calculated the demand/capacity ratio for that check and potentially listed that value as the controlling demand/capacity ratio for the opening, but correctly did not flag the opening as failing if that ratio exceeded 1.0. Hence it was possible that the program listed a demand/capacity ratio greater than 1.0 but did not indicate that the opening failed.

Effect: Potentially, in View/Update and on-screen, an incorrect demand/capacity ratio greater than 1.0 was listed for the opening, even if the opening passed all of the necessary design checks (the design report listed the correct value).

CASTELLATED BEAMS FREEZING: While optimizing castellated beam sizes for a range of opening spacing, e, the program may have failed to correctly determine an e-max for some beams’ designs.

Effect: The optimization process for certain castellated beam designs stalled during a Design All, the design of the remaining beams could not be obtained.

NON-COMPOSITE BEAM SPAN/DEFLECTION DISPLAY VALUES:  When the Show Values option of the Process – Design Colors command was invoked, non-composite beams did not show the correct deflection interaction value if the deflection criteria for the beam only included a limit on the Live Load L/d ratio.

Effect: The designs were correct; the beam designs correctly considered the Live Load L/d deflection limit for non-composite beams. However, the Process – Design Colors command did not show the correct deflection interaction value in the display if the deflection criteria for the beam only included a limit on the Live Load L/d ratio.

Steel Column

AISC 360-16 DESIGN WARNING: In the calculation of the P-delta multiplier, B1y, if alphaPr was greater than Pe1y the warning given by the program incorrectly stated that alphaPr was greater than Pe1x.

Effect: Warning text error only. The warning incorrectly referenced Pe1x rather than Pe1y.

Concrete Beam

ACI 318 SEISMIC PROVISION DESIGN SHEAR, Ve*: When only some of the load cases were analyzed in RAM Frame, the portion of Ve attributed to the gravity load cases was sometimes greater than the actual gravity load case shear.

Effect: Design shear, Ve, used in ACI 318-11 Section 21.5.4.1 and ACI 318-14 Section 18.6.5.1, may have been wrong; when the error occurred, it was almost always conservative, but not necessarily, so in rare cases may have resulted in an unconservative design. If all of the load cases in RAM Frame were analyzed, the error did not occur.

CONCRETE BEAM FORCE ENVELOPES*: If  not all cases were analyzed in RAM Frame, the Force Envelopes in Concrete Beam were calculated incorrectly.

Effect: Incorrect results.

Concrete Column

COLUMNS UNBRACED OVER MULTIPLE STORIES*: When calculating the special provision shear requirement of ACI 318-14 Section 18.7.6.1.1 (or analogous clauses in earlier codes), if a column was unbraced over multiple stories, the program did not take into consideration the probable moment contribution from beams in the upper story segments of the column when designing the lower story segments of the column.

Effect: Potentially there was an underestimation of special provision shear.

ACI 318-11 SECTION 10.3.5 LIMIT ON NET TENSILE STRAIN: The limit of 0.004 on the net tensile strain of the reinforcement for lightly loaded columns was not being applied.

Effect: The maximum reinforcement ratio for columns imposed by the minimum limit on the tensile strain at nominal strength was not being considered.

Concrete Wall

COUPLING BEAMS COMPOSED OF DIFFERENT WALL PANELS*: If a coupling beam was composed of portions of two wall panels (i.e., the upper portion of the coupling beam was from the panel above and the lower portion of the coupling beam was from the panel below), the design forces may have been incorrect, only including the forces in the lower portion of the coupling beam.

Effect: Incorrect design of coupling beams for the condition described.

COUPLING BEAM UPDATE DATABASE: If changes were made to the reinforcing for coupling beams, and then saved using the Update Database command, the original design results were not cleared, and a subsequent View/Update would show the results from the original configuration rather than the saved configuration.

Effect: Incorrect design results were shown in View/Update after the coupling beam reinforcement was changed and updated.

Frame – Analysis

USER-DEFINED WIND LOADS ON SEMIRIGID DIAPHRAGM*: When the wind loads were user-defined rather than generated and the diaphragm was specified as Semirigid, the wind load distribution on skewed diaphragm geometries were not correct because the program used real building lengths instead of projected lengths. Even though the total applied load was correct, the wind load profile (wind load distribution along building surfaces) was not correct.

Effect: For diaphragm geometries with skewed faces, total wind load was correct, but the wind load distribution along any given face was not.

USER-DEFINED WIND LOADS ON SEMIRIGID DIAPHRAGM*: If deck assignment (deck polygon) did not fully extend out to the end of slab edges and the deck was specified as Semirigid, the program applied user-defined wind loads at wrong locations. It was expected such wind point loads should be applied to mesh nodes close to edges, but they were applied to nodes at other locations.

Effect: Wind loads were not assigned to nodes along edges if the deck polygon did not extend out to that slab edge. The error was generally very obvious if the Process – Results – Applied Story Forces command was invoked to display the loads on the diaphragms.

USER-DEFINED WIND LOADS ON SEMIRIGID DIAPHRAGM: When the wind loads were user-defined rather than generated and the diaphragm was specified as Semirigid, the applied loads were greater than necessary if the diaphragm had a concave geometry.

Effect: The applied wind loads were greater than what the user had defined.

INCORRECT MEMBER FORCES FOR BEAM WITH SPRING CONNECTION AND SEMIRIGID DECK*: The program produced incorrect member forces for beams if the beam had been assigned a spring connection and the deck was Semirigid.

Effect: Member forces for beam were incorrect.

INCORRECT FORCE/MOMENT DIAGRAGMS FOR BEAM WITH SPRING CONNECTION: Member Force diagrams were incorrect on beams if the beam had been assigned a Spring connection type and the option to Include Effects for rigid end zones was selected.

Effect: The diagram was shifted and the program was not consistent in properly displaying the values at rigid-end-zone distances versus at the face of joint.

WRONG SIGN REPORTED FOR BEAM AXIAL AND MINOR MOMENT FOR DYNAMIC CASES*: Beam axial force and minor moment for dynamic load cases were reported with the wrong sign if the "Apply sign" option was selected for dynamic analysis results and member forces were reported at face of joint.

Effect: Wrong sign reported for beam dynamic axial force and minor moment.

CRASH WHILE ATTEMPTING TO DISPLAY GRAVITY WALL STRESS: Gravity walls are included in the analysis if they support two-way decks and the option to include them in analysis is selected. However, if gravity walls were included in a previous analysis and then not in the current analysis, the program subsequently crashed if the Process – Results – Stress and Internal Force Contours command was invoked.

Effect: Program crash.

USER-DEFINED STORY WIND AND SEISMIC LOADS*: In a very rare case, user entered values for user-defined story forces were lost either upon closing the load case dialog or after an analysis was performed.

Effect: User entered values for wind and seismic forces were lost.

NBC OF CANADA 95 WIND LOAD CASE REPORT: For the NBC of Canada 1995 wind load case, the Loads and Applied Forces report only listed the building frequency for the X-direction even if both X- and Y-direction wind cases were analyzed.

Effect: Report error only, the Y-direction frequency was not listed.

EUROCODE 1991-1-4:2005 AND EUROCODE 1991-1-4:2005 UK NA WIND CASE: The program crashed for Eurocode 1991-1-4:2005 and Eurocode 1991-1-4:2005 UK NA wind load cases if the ground level was not At Base in the Criteria – Ground Level command.

Effect: Program crash.

EUROCODE ENV 1991-2-4:1995 WIND LOAD CASE*: For Eurocode ENV 1991-2-4:1995 wind load case, the program did not immediately recognize changes to the Ground Level selection in the Criteria – Ground Level command, the program continued to use the ground level from the previous run.

Effect: Calculated wind forces were not correctly reflecting ground level set for that run.

ZERO WIND PRESSURE FOR CHINA GB50011 WIND LOAD CASE*: The China GB50011 wind load generator was not generating any wind loads.

Effect: No wind pressure and forces calculated for the load case.

DISPLAYING MEMBER FORCES ENVELOPE VALUES: The Process – Results – Member Forces Envelope command took an exceptionally long to display member force envelope values on screen if the model included dynamic load cases.

Effect: Prohibited viewing of member forces envelopes if there were dynamic load cases.

CRASH WHEN SWITCHING BETWEEN MODES: The program would sometimes crash when switching between the various modes (Load Combinations, Steel, Drift, and Shear Wall Forces).

Effect: Program crash.

DURAFUSE PANEL ZONE ROTATION FOR DYNAMIC LOAD CASE: For dynamic load cases, the Member Forces report for a column in a moment frame using the DuraFuse moment frame connection reported incorrect Panel Zone Rotation values.

Effect: Incorrect Rotation values reported.

STRESS CONTOUR VALUES NOT DISPLAYED IN PLAN VIEW: When displaying stress contours in Plan View, the option to Show Stress Contour Values did not work, the values were not displayed.

Effect: Stress contour values could only be displayed in 3D View, not in Plan View.

STRESS CONTOUR DISPLAY IGNORED EXTENTS: If the extents of the view had been limited using the View – Extents command, those extents were ignored when the stress contours were displayed.

Effect: Wall and diaphragm stress contours were displayed for all levels, even if the user had attempted to limit the stories being displayed using the View – Extents command

PROGRAM FREEZE WHEN DISPLAYING STRESS CONTOURS FOR LOAD COMBINATIONS: In Load Combinations mode, the program become unresponsive when the Process – Results – Stress and Internal Force Contour command was invoked.

Effect: The contours could not be viewed in Load Combination mode.

ECCENTRIC GRAVITY MOMENT AT TILT-UP WALL GAP JOINTS: Eccentric gravity moment from gravity beams framing into the joint was intended to be equally distributed to the tilt-up wall panels common to the joint. If both (or all, if more than two panels converged at a joint) panels had been assigned to have a gap there, the moment was equally distributed properly, but if one of the panels had not been assigned to have a gap there, it was not assigned any eccentric gravity moment; it was all assigned to the panel with the gap assignment.

Effect: Tilt-up panels without gap assignments may not have been designed for the intended eccentric gravity moments from beams framing into the wall end.

CRASH AFTER DELETING LOAD CASES: If load cases were deleted after they had been analyzed the program was susceptible to crashing on the subsequent analysis.

Effect: Program crash.

CRASH WHEN SWITCHING BETWEEN MODES: Program crashes were common after invoking the Shear Wall Forces mode and then switching to another mode.

Effect: Program crash.

Frame – Steel Standard Provisions

VIEW/UPDATE WITH DYNAMIC LOAD CASES: Investigation of different beam sizes in the View Update dialog for models with dynamic load cases was often unresponsive, leading users to believe a crash had occurred.

Effect: While investigating other beam sizes in View Update dialog box, the program became unresponsive while internally processing combinations with dynamic load cases. Models without dynamic combinations did not result in delays when investigating alternate beam sizes.

SIDEPLATE OR DURAFUSE CONNECTION UNBRACED LENGTH: For the SidePlate and DuraFuse connections, the unbraced length of beams and columns should be the clear distance between faces of members (regardless of the selections for Rigid End Zones in the Criteria – General Criteria command). However, the program was calculating the unbraced lengths based on those selections.

Effect: For SidePlate and DuraFuse connections, the unbraced length of members used in design was correct if the option to Include Effects was selected with 0% reduction, but any other selection would result in a conservative (longer) unbraced length. The analysis was correct, only the unbraced length may have been incorrect.

SCBF COLUMNS - MAX COMPRESSIVE FORCE: The 0.75 reduction factor was not applied to the transient load combinations for SCBF Columns designed according to AISC 341-10 and -16 ASD.

Effect: The max compression design force for SCBF Columns designed according to AISC 341-10 and -16 ASD and governed by combinations with transient loads was not reduced by the transient load reduction factor of 0.75. Designs may have reported incorrect controlling load combinations.

Frame – Steel Seismic Provisions

AISC 341-16 BASIC REQUIREMENTS FOR SCBF BEAMS*: AISC 341-16 Section F2.5a Basic Requirements requires that SCBF members satisfy the requirements of Section D1.1 for highly ductile members; however, the program was only applying the moderately ductile limits on SCBF beams.

Effect: SCBF beams checked according to AISC 341-16 Basic Requirements, Section D1.1, used Moderately Ductile rather than Highly Ductile limits. Some beams should have failed under the more stringent flange b/tf limit for highly ductile members.

CONTINUITY PLATE CHECK STATUS: When a Joint Code Check for IMF and SMF joints was performed and it was determined that continuity/stiffener plates were required but web plates were not, the symbol displayed for the joint was incorrect, indicating that web plates were required. Also, the Seismic Provisions Joint Code Check report incorrectly stated that both web plates and stiffeners were required although it correctly only listed the stiffener plate information.

Effect: When stiffeners were required, both the symbol displayed for the joint and the report incorrectly indicated that web plates were required.

ROUND HSS REQUIRED COLUMN STRENGTH: The reported required column strength per the requirements of Section D1.4a of AISC 341-10 and AISC 341-16 for SCBF and BRBF with round HSS columns with different orientations for columns within a multi-story stack was calculated incorrectly; the amplified seismic load Emh or Ecl in certain chevron bracing configurations was incorrect.

Effect: The amplified seismic load, Emh or Ecl, determined respectively according to Sections D1.4a of AISC 341-10 and AISC 341-16 for SCBF-V and BRBF-V for round HSS columns was incorrect when columns within a multi-story column stack had varying column orientations. When no braces frame into the top of column in a given axis, the column is designed for an accumulation of axial loads from supported stories and any unbalanced beam shear reactions. When braces frame into the top of the column in a given axis, only the vertical reaction of the braces and any accumulated axial loads from supported stories are considered. When the column orientation for a round column changed from level to level, these values were incorrectly mixed.

DURAFUSE HSS JOINT CHECK*: Some DuraFuse joint configurations at HSS columns were incorrectly considered invalid and so were not designed.

Effect: The joint check for the DuraFuse connection was not performed in many cases when the column was an HSS.

Data Extractor

INCORRECT DATA EXPORTED FOR GRAVITY BEAM REACTIONS: In the GravLoadReactionsOnBeams tab of the Loads tables, there were several columns that should have been expanded to show an array of values rather than a single value. For example, Columns BC-BH listed the tributary areas on the beam; however there are three such values for each beam corresponding to the left cantilever, the span, and the right cantilever. But only a single value was listed, and it was incorrect, it didn’t even correspond to the value for any of those segments. There were several other columns with similar problems, notably Columns CA-CB listing the MultiLevelFlag. These columns have now been expanded to contain the full arrays of values.

Effect: Columns BC-BH, BQ-BT, CC-CN, CA-CB and CU-CZ had erroneous values. The correction required that several existing columns of data were relocated to the right. Of note, Column DS, that contained the StoryID, is now Column EQ.

NOTE: The format of the table on the BravLoadReactionsOnBeams tab has been modified! If you have written any spreadsheets or programs that use any of the columns to the right of Column BB you will need to correct your program to use the relocated columns. Review the documentation carefully to see the new format.

INCORRECT DATA EXPORTED FOR GRAVITY COLUMN REACTIONS: In the GravLoadReactionsOnColumn tab of the Loads tables, there were several columns that should have been expanded to show an array of values rather than a single value. For example, Columns Q-AB listed beam reactions on the sides of the columns, used for skip loading and unbalance moments; however only a single side’s value was listed rather than all four sides’ values, and that value that was listed was wrong. All of the columns to the left of AU had a similar problem. These columns have now been relocated and expanded to contain the full arrays of values.

Effect: Columns Q-AB and AV-CQ had erroneous values. Columns Q-AB have been abandoned (filled with 0.0 and labeled as unused), and the values in Columns Q-AB and AV-CQ have been expanded and relocated to the right of Column AU.

NOTE: Values in Columns A-P and AC-AU remain unchanged, but all other Columns have been reformatted. If you have written any spreadsheets or programs that use any of the affected columns you will need to correct your program to use the relocated columns. Review the documentation carefully to see the new format.

Appendix A

Bentley CONNECT Licensing – Subscription Entitlement Service

Bentley CONNECT Licensing has now been renamed Subscription Entitlement Service. CONNECT Licensing was first implemented in the RAM Structural in v16.00. This licensing monitors current usage and, if an attempt is made to use a program or module for which there is no available license, the program will give a warning. Important information is given in the v16.00 Release Notes.

More information on CONNECT Licensing / Subscription Entitlement Service can be found at:

https://www.bentley.com/en/subscription-services-portal/subscription-entitlement-service

User and Administrator instructions can be found here:

https://communities.bentley.com/products/licensing/w/licensing__wiki/37813/subscription-entitlement-service-formerly-connect-licensing

and a short guide has been posted here:

https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/273502

CONNECT License / Subscription Entitlement Service requires all users to sign-in in order to use any Bentley programs. If you do not already have a Bentley ID, go to http://www.bentley.com/profile and select the Sign Up Now link.

NOTE: If you haven’t done so already, before using any version 16.0 or newer, the person at your company that has the role of Administrator for the Bentley products must configure the license so that it gives the overuse warnings. Otherwise, by default no warnings will be given. Instructions can be found here:

https://communities.bentley.com/products/licensing/w/licensing__wiki/38540/1---subscription-entitlement-service-for-administrators-getting-started

Review all of the information, but in particular, note the section on Entitlement Management, and in that document note the instructions on License Alerting. Generally, for License Alerting you will want to Enable Alerts, and then input the number of licenses that you own for the particular product.

CONNECT Licensing / Subscription Entitlement Service is revolutionary. It warns you against incidental overuse of the program, but when you have a temporary heavier work load it allows you to intentionally use more licenses than you own, at a fraction of the cost of purchasing an additional copy. Subscription Entitlement Service gives you the information you need to control usage and make those decisions.

Bentley CONNECT

In addition to providing the overuse warning described above, Bentley CONNECT offers several benefits. Listed here are three key features:

CONNECT Advisor

CONNECT Advisor provides links to pertinent articles, short training videos, courses and webinars. It can be accessed by selecting the Bentley Cloud Services – CONNECT Advisor command in the RAM Manager, or by selecting the CONNECT Advisor icon from the tool bar in any of the modules.

CONNECT Center

When you sign in to your Bentley account you now have easy access to CONNECT Center. This personalized portal gives you access to Usage reports, site configuration information, downloads, and Learning information on webinars, seminars and events, and includes a transcript listing the Bentley courses that you have completed. Your personal portal also lists your recent projects with a portal into analytics on that project. CONNECT Center can be accessed by selecting the Bentley Cloud Services – CONNECT Center command or by selecting the Sign In command in the upper right corner of the RAM Manager screen.

CONNECTED Projects

All of Bentley’s CONNECT Edition programs, including RAM Structural System, allow models to be associated with a project. Multiple models, from any of the Bentley products, can be associated with a given project. This simplifies the process of keeping track of work done for a project, and will enable analytics to be performed and reported for the project.

A ProjectWise Projects portal enables you and your project teams to see project details required to evaluate team activity and understand project performance.

• View project activity by site, application and user
• Gain insights into the users who are working on your projects and their effort
• Register and manage your CONNECTED Projects
• Access ProjectWise Connection Services including ProjectWise Project Sharing, ProjectWise Project Performance Dashboards and ProjectWise Issue Resolution Administration

When a model is Saved in this version the program will ask for a Project to which the file is to be associated. Projects can be registered (created) from your Personal Portal, or from the Assign Project dialog by selecting the + Register Project command.

Appendix B

Product Licensing FAQ – RAM Structural System: Blocking Use of Modules and Programs

VERSIONS 17.00 AND NEWER

The RAM Structural System contains links to three related Bentley products, RAM SBeam, RAM Concept and RAM Connection, providing design interoperability. Each of those programs have their own licenses. It is possible for a client to have licenses for some programs but not for the others. Because of the ease with which these programs can be invoked, a method of restricting the use of each has been incorporated in order to prevent unwanted or inadvertent usage by an unsuspecting user from being logged against the licenses that the company actually owns.

Note that if you have installed CONNECT versions of these programs and have correctly set up the warnings on entitlements you will receive a warning if overuse is about to occur; you may find it advantageous to rely on these warnings rather than blocking their use entirely as described below.

RAM SBeam is invoked using the Process – Export to SBeam command in the Steel Beam module. RAM Concept and RAM Connection are invoked using the tool bar buttons on the left of the RAM Manager screen:

or by using the Model or Design menu items:

If RAM SBeam, RAM Concept, or RAM Connection are not installed, they will not be available to be selected.

In RAM Manager, the Tools – Manage License Restrictions command opens the following dialog:

This provides a mechanism for the user to prevent a program from being inadvertently executed. When the RAM Structural System is first installed all of these options are selected. It is important therefore to execute this command and deselect any links for which the user wants to restrict access.

To prevent a program link from being executed, deselect that item.

If a link is deselected here and that link is subsequently invoked, the following dialog appears:

If Allow is selected the program will open, and usage will be logged. If Cancel is selected the program will not open and no usage will be logged. Settings opens the previous command, allowing the user to modify the selections of the allowed programs.

Note that there is also a link to Bentley’s ProjectWise for project management. It is available through the File – ProjectWise command. Its use is not restricted through the Tools – Manage License Restrictions command described above. It should only be invoked if you have a license for it.

VERSIONS 14.07 Through 16.01

The RAM Structural System is composed of several modules, each of which has their own license. The program also contains links to two related Bentley products, RAM Concept and RAM Connection, providing design interoperability, as well as a link to Bentley’s ProjectWise for project management. Each of those programs also have their own licenses. It is possible to have several licenses of one or more modules, and few or no licenses of other modules. Because of the ease with which these various modules and programs can be invoked, a method of restricting the use of each has been incorporated in order to prevent unwanted or inadvertent usage by an unsuspecting user from being logged against the licenses that the company actually owns.

These modules are invoked using the tool bar buttons on the left of the RAM Manager screen:

or by using the Model or Design menu items:

If RAM Concept or RAM Connection are not installed, they will not be available to be selected.

There is no license associated with RAM Manager, so no usage data is logged against it, but usage data is logged against each of the other modules as soon as they are invoked.

In RAM Manager, the Tools – Manage License Restrictions command opens the following dialog:

This provides a mechanism for the user to prevent a module from being inadvertently executed. When the program is first installed all of these options are selected. It is important therefore to execute this command and deselect any modules or links for which the user wants to restrict access.

To prevent a module or program link from being executed, deselect that item.

If a module is deselected here and that module or link is subsequently invoked, the following dialog appears:

If Allow is selected the module will open, and usage will be logged. If Cancel is selected the module will not open and no usage will be logged. Settings opens the previous command, allowing the user to modify the selections of the allowed modules.

Note that there is also a link to Bentley’s ProjectWise for project management. It is available through the File – ProjectWise command. Its use is not restricted through the Tools – Manage License Restrictions command described above. It should only be invoked if you have a license for it.

VERSIONS 14.06 AND EARLIER

Versions prior to V14.07 lacked the ability to manage these license restrictions, restrictions could only be achieved by deleting the module from the installation Prog directory. If you are using an earlier version and want to prevent use of a module, delete the file(s) listed here for the module to be prevented:

I am getting the following error during analysis. How do I fix that ?

***Error*** Modulus of Elasticity Missing For Element ...

The error means that material has not been assigned to certain elements. You can graphically find out those elements by choosing Select > By Missing Property > Missing Elasticity. The elements with missing attributes will be highlighted. You may then assign the appropriate material to those elements using the graphical user interface.

Another quick way to fix the issue, specially of you have only one type of material for the whole model, is to go to the input command file and type in the following commands under the CONSTANTS section as shown next

For Steel:
CONSTANTS
MATERIAL STEEL ALL

For Concrete:
CONSTANTS
MATERIAL CONCRETE ALL

This page contain solutions to miscellaneous analysis related issues

1. My hand calculations do not match the displacements being reported by STAAD.Pro
2. Lifting Analysis
3. I defined a composite deck and I am getting the following warning during analysis   ***WARNING: MEMBER     1 HAS COMPOSITE PROPERTY ASSIGNED TO IT AND HENCE THE MATERIAL CONSTANTS  ARE SET AS THOSE OF STEEL. CURRENT SPECIFICATION IS IGNORED EXCEPT DAMPING RATIO
4. Base plate connection for a tube column
5. Unable to load Bentley.LicLib.dll.Error:126.the specified module could not be found
6. Changing units for existing input data in STAAD.Pro
7. Copying connection templates
8. Error "LoadLibrary failed with error 126: The specified module could not be found" 
9. STAAD.Pro model with connection data in it is not opening in STAAD.Pro SS6 ( 20.07.11.70 )
10. Unable to activate RSS Feed connection message
11. Unable to cast 'STAAD.Pro' COM object to 'OpenSTAAD' object
12. [[** WARNING ** A SOFT MATERIAL WITH (1.0 / 1.526E+01) TIMES THE STIFFNESS OF CONCRETE ENTERED. PLEASE CHECK.]]
13. [[What is the SET NL command]]
14. [[***Error*** Modulus of Elasticity Missing For Element]]

Release Date: January 2021

Version: RAM Concept CONNECT Edition V8 Update 2

Version Number: 08.02.00.146

Download and Installation Instructions

Current and past RAM Concept releases can be downloaded from the Bentley Software Downloads page. After signing-in, the RAM Concept installers can be located by selecting RAM in the Brand menu and clicking Apply or searching for RAM Concept in the Product Search box.

RAM Concept V8 CONNECT Edition Update 2 can also be installed through the CONNECTION Client update service or through the Structural Enterprise Hub.

RAM Concept V8 CONNECT Edition Update 2 can be installed concurrently with versions prior to V8. The installation of this version will automatically uninstall RAM Concept V8 or later.

Product Licensing

More information on product licensing can be found here. A download link to a licensing user guide, which includes instructions for setup and configuring license threshold alerts, can also be found on that web page.

Technology Preview Feature

RAM Concept CONNECT Edition V8 Update 2 includes the Technology Preview feature discussed below.

iTwin Design Review

RAM Concept now integrates with Bentley iTwin Services with the iTwin Design Review feature.

Bentley iTwin Design Review is a collaborative service hosted on the web that allows two or more interested parties to communicate with one another in the context of a 3D model or, more accurately, an iTwin. The iTwin Services Add-in within the desktop application publishes the analysis model to an iTwin Design Review session, and therefore, into an intuitive point of collaboration that facilitates review of design work in progress.

The web-based interface (accessible with a web browser) of Design Review offers a set of commands for navigating, viewing from different perspectives, isolating key elements, and clipping views.  

Several review tools are included with the service: 

• Measurements, including distance, area, location, radius, and angle 
• Querying elements for physical information, such as dimensions, construction materials, and coordinates 
• Querying analytical information, such as member fixities, applied loads, and reactions 

More information on this feature can be found here.

Please use this Technology Preview feature in your normal business environment as needed to form an opinion concerning their performance. Bentley personnel welcome your valued feedback as you evaluate its capabilities. Please be aware that at some point, you may receive notice from Bentley that such use must cease or the Technology Preview feature will become unavailable to you. As we receive feedback, this Technology Preview may also be enhanced, updated or also discontinued without notice. As a Technology Preview, this feature is provided to you “as-is” without the benefit of any Bentley warranty, indemnity or support obligation.

Enhancements

RAM Concept CONNECT Edition V8 Update 2 includes the enhancements discussed below.

Python Scripting API

A Python scripting API, with limited access to the data and functionality in RAM Concept, is now available. This feature allows you to automate routine tasks such as creating models, running analyses, and accessing results. Over time, we expect to expose almost all of the data and functionality in RAM Concept through the scripting API. Examples of workflows that are supported in this release include: exporting column reactions for load takedown, exporting elevations and coordinates at increments along tendon profiles, and importing point loads from spreadsheets.

The scripting API permits RAM Concept to be run “headless” (from a command line, without the graphical interface). RAM Concept and/or RAM Concept Post Tension licenses are consumed when running the program in this mode. Normal license rules and restrictions still apply.

More information on this feature, including a Getting Started Guide, sample code, and documentation, can be accessed in the program from the Help menu by clicking on API Documentation.

New Creep and Shrinkage Models for Load History Deflections

The ACI 209.2R-08/GL 2000, AS 3600-2018, and Eurocode 2-2004 creep and shrinkage models are now implemented for use in the load history deflection calculations. The ACI 209R-92 model remains and will be the selected code when models created in earlier versions are opened in this or future versions.

The options in Load History / ECR tab of the Calc Options dialog have been reorganized, as shown in the image below, to accommodate the new creep/shrinkage models. The General Parameters marked in the image apply to all creep/shrinkage models. The Model Specific Parameters are used to automatically calculate basic creep and shrinkage coefficients and adjustment factors that are defined in the selected creep/shrinkage model. Code Specific parameters that do not apply to the selected creep/shrinkage model are automatically disabled when that model is selected for use. The creep factor and shrinkage strain defined in the ECR box and marked in the image are used for the ACI 209R-92 model only.

Meshed Rigid Support Regions

An option to mesh a rigid support region is now available in the column and wall property dialogs. When utilized, the rigid support region option forces the program to mesh elements within the plan area of the column elements and walls. The flexural and torsional stiffness of these elements is then modified using the specified “Slab Support Region Stiffness Factor” in the same dialog. The default stiffness factor is 10, which represents the maximum factor permitted by RAM Concept and attempts to create a rigid zone over the supports. This feature may help predict more accurate floor deflections, especially for floors with large columns.

Table for Load History Deflection Analysis Results

A table for load history analysis results is now available on the Load History Deflections Layer. The tables inclues results and parameters that are directly used by the program to calculate the load history deflections and parameters that are not directly used but are useful for understanding the relative importance of different behaviors, like internal and external shrinkage restraint. A separate table is available for each load history step. Each table includes information for all sections defined in the model. More information on this feature can be found here.

Precompression Checks for Post-Tensioned Sections

A maximum and minimum precompression check for post-tensioned sections has been added to the User Minimum Rule Set. The minimum and maximum precompression limits are defined by the user and are a property of the span segment or design section.

The average precompression in the section can be calculated using the Balance Loading, which includes the effects of diversion of prestress (e.g. into rigid supports) or FpsAse/Ac, which uses the vector component of the effective tendon force perpendicular to the cross section and excludes restraint. When the average precompression stress in the section is less than the defined minimum value or greater than the defined maximum value, a design criteria failure is reported.

These checks are also included in the PT Optimization feature. When the precompression calculations are activated, the user can save time preparing models for optimization by using a wide max/min range (for example, min number of strands = 0, max number of strands = 100) and use the Optimizer to find a solution with the specified precompression range.

Other Changes

RAM Concept CONNECT Edition V8 Update 2 also includes the changes discussed below.

Load History Tension Stiffening Model

RAM Concept uses the Eurocode 2 tension stiffening model for all load history calculations regardless of the selected creep/shrinkage model. This tension stiffening model utilizes a Beta parameter, which Eurocode 2 states should be taken as 1 for short-term loading and 0.5 for long-term loading (see Clause 7.4.3). Previous versions of RAM Concept used Beta = 0.5 when using that code equation. Some experts have concluded that Beta = 0.5 is equivalent to reducing the cracking moment by about 30 percent and is an approximate way to account for shrinkage induced cracking (i.e. internal and external shrinkage restraint). Since RAM Concept always rigorously calculates the effects of internal restraint and uses the Shrinkage Restraint % parameter to account for the effects of external restraint, RAM Concept now always uses Beta =1 to avoid double counting those effects.

Load History Shrinkage Restraint %

In the Load History Calc Options dialog, the user now has the option of entering a specific percentage for external shrinkage restraint or selecting one of the pre-set options. The pre-set options are mapped to assumed percentages as tabulated below.

In prior versions, a default shrinkage restraint percentage that was used in new RAM Concept models was 20%. The default has now been changed to None, which results in a shrinkage restraint of 0%. This percentage may be appropriate for a typical, intermediate floor in a multi-story structure. However, a larger percentage may be more appropriate for other conditions (podium slab, transfer plate, basement slab, etc.).

Load History Calculations - Strength Adjustments for Time of Loading ACI209R-92 Creep/Shrinkage Model

The ACI 209R-92 model calculates creep strain based upon the modulus of the mean concrete strength at time of loading. Since RAM Concept calculates curvatures based upon the concrete modulus value at 28 days, an adjustment is needed to convert creep strains to the code model values. RAM Concept now accounts for this adjustment by modifying all creep strains by the ratio of the mean elastic modulus at 28 days (E_cmt28) to the mean elastic modulus at the time of loading (E_cmt0).

A similar adjustment is applied to the modulus of rupture, which is used for the concrete flexural tension strength in the tension stiffening equation. In previous versions, the rupture strength was valued using the 28-day design concrete strength that was defined in the Materials window. RAM Concept now converts the modulus of rupture from 28 days to the actual time of loading to account for the reduced concrete strength at early age loading (before 28 days).

Punching Shear Sections - Exclude Acute Angles

In rare cases, the punching shear check in previous versions may have been governed by sections with acute angles like the one shown in the image below. A change was made to limit the angle between adjacent edges of the punching shear section to 45 degrees. This change will eliminate unrealistic sections from consideration, which will typically improve the reinforcement design of affected punching shear checks.

Resolved Issues

RAM Concept CONNECT Edition V8 Update 2 includes fixes for the issues discussed below.

APolyLine2D and ABoundaryShape2D Errors When Generating Design Strips

In some models, snap issues with span segment ends or other geometry issues caused an ApolyLine2D or AboundaryShape2D error to occur when design strips were generated. The errors prevented the analysis from completing. Additional details can be found here.

File Compatibility Warning

RAM Concept CONNECT Edition V8 Update 2 can read all previous file formats, but writes files in a format that cannot be read by previous versions.

Security Release Notes

Not applicable to this release.

Release Date: 13th January 2021

Version: ISM Revit Plugin CONNECT Edition V11 Update 2

Version Number: 11.02.00.14

Download Instructions

ISM Revit Plugin can be downloaded from Bentley Cloud Services here. After signing in to CONNECTION Center, select Software Downloads under My Services. Once on the Software Fulfillment page, ISM Revit Plugin installers can be located by performing a search on "ISM Revit".

Special Notices

The installation of ISM Revit Plugin CONNECT Edition will automatically uninstall any previous versions that were installed. This version of ISM Revit Plugin can be run in Revit 2019, 2020, and 2021.

ISM Revit Plugin requires ISM and Structural Synchronizer (both of which are installed with Structural Synchronizer). More information on ISM and Structural Synchronizer can be found here.
 

New Features

In this update, we added support for REVIT 2021.

Installation

[[Installing Additional Versions of Revit]]

General

All Red x's in Mapping When Exporting from Revit

[[Zero Length Error in Revit]]

[[Section Mapping Importing into Revit TN]]

[[ISM Revit Link Plug-in Parametric Shape Mapping]]

[[Add RAM Special Joists and Girders to Revit Joist Families]]

[[Material Mapping Importing into Revit TN]]

Creating a New Shared Mappings Database

Deck Mapping Importing into Revit

[[Revit Brace or Beam Off Axis Warning]]

Revit External Tool Failure

Revit has Experienced an Unexpected Error

Revit to RAM Structural System workflows

Exporting Just Levels and Grids

ISM Coordinate Mapping with Revit Structure

ISM Lateral Members not Importing into RAM Structural System from Revit

RAM Manager exports Point Reactions = Zero cannot import into Revit

Wall Openings not Imported into RAM Structural System

Other Workflows

[[Revit Slabs for Ram Concept]]

How does changing the ground level affect restraints?

The ground level for Frame analysis can be set through Criteria - Ground level. 

The default is for the model base to be the ground level. This is the bottom of the lowest story in the model story data.

The program will automatically provide a support point or restraint at the base level under every lateral column and wall. Additionally, where lateral columns or walls terminate on a higher story with nothing below them, additional support points are provided.

When you set an upper level to be the Ground Level, the program applies lateral restraint in the global X and Y directions to the diaphragm (or multiple diaphragms) at that story. This is analogous to having a vertical roller support on all the nodes attached to those diaphragms. Nodes that are disconnected from the diaphragm are no longer constrained by any ground level restraint. Any subterranean story below the ground level is also treated the same way.

In models with the ground level above the model base, overturning of the structure will be partially resisted by force couples formed by reactions at the ground level and level below (aka prying action). These reactions result in shear reversals and high shear forces in columns and walls on the subterranean levels.

How does changing the ground level affect wind and seismic loads?

Starting in version 17.02.00.130 (January 2021) there is a separate control for the ground level for wind loads and the ground level for support points.

The information below applies where the Wind Generation ground level is the same as the Analysis ground level, and to older versions.

In the calculation of wind and seismic loads, the program assumes the ground level as set under Criteria - Ground level is the zero elevation. All heights using in calculating wind pressures or seismic load distribution are measured up from this ground story. 

Can I have the loads calculated based on an elevated ground level, but not have the ground level restrained?

Yes, starting in version 17.02.00.130 there is a separate control for the ground level for wind loads and the ground level for support points.

In older versions, "User Defined Story Forces" were the alternative where the diaphragms are rigid or semi-rigid. We usually recommend to run the model first with an elevated ground level. Then print the Loads and Applied Forces report. Next, create new wind (or seismic) load cases, using the "User Defined Story Force" option under Loads – Load Cases, that are based on that output and delete the original program calculated loads. Finally, reset the ground level to the base.

See Also

RAM Frame - Building and Frame Story Shear

RAM Frame - Wind Loads [FAQ]

RAM Frame - Seismic Loads [FAQ]

How is the wind typically applied to the model?

The slab edge determines the exposure (Ram Frame – Loads – Exposure) and we assume some kind of vertically spanning cladding transfers the loads to the diaphragms. The program calculates a total force based on total exposure, considering one windward surface and one leeward surface per diaphragm. Where the wind may hit more area, user defined loads should be used.

How are IBC/ASCE7 wind pressures calculated?

ASCE 7-10 includes three different procedures for wind load calculation: directional, envelope, and wind tunnel procedure. Only the directional procedure is implemented into the program. Program generated wind loads calculated per ASCE7-10 are ultimate loads.

IBC 2006/2009 Section 1609.1.1 refers to Chapter 6 of ASCE 7-05 for Wind load requirements. It lists alternative methods and wind speed values. ASCE 7-05 includes three methods for wind load calculation: Method 1- Simplified Procedure, Method 2- Analytical Procedure, and Method 3- Wind Tunnel Procedure. Method 2 is further composed of two different provisions: a method for Low-Rise Buildings and a method for Buildings of Any Height.  Among these methods, only Method 2-Analytical Procedure for Buildings of Any Height is implemented. Program generated wind loads calculated per ASCE7-05 are service loads.

Section 1609 of IBC 2003 gives wind requirements specifically focused on a simplified procedure acceptable for enclosed, low-rise, simple diaphragm buildings having a height of less than 60 feet. For other types, it refers to Section 6 of ASCE 7-02 where three methods described above for ASCE 7-05 are mentioned. Again, only Method 2-Analytical Procedure for Buildings of Any Height is implemented. Program generated wind loads calculated per ASCE7-02 are service loads.

User defined story forces may be used to apply Method 1- Simplified Procedure, Method 2- Analytical Procedure for Low Rise Buildings, or Method 3- Wind Tunnel Procedure. In version 15.04 a feature was added to make it easier to paste in forces from a wind tunnel test.

How are the wind pressures viewed?

You can see the total force using Process – Results – Applied Story Forces, or Report - Loads and Applied Forces to see the intermediate wind pressure calculations. 

The Report – Exposure Boundaries is useful for visualizing the exposed surfaces of the model in a compressed Elevation View.

Is wind uplift considered?

No, the program only applies the total horizontal force for each story or diaphragm. Uplift loads are not yet considered.

While there is no good work around for this limitation some users apply negative magnitude Live Loads in order to check the beams (or foundations) for uplift. It's important to note that the program still sees this as a Live load and factors it accordingly, so some adjustments in the magnitude of the applied load or customization of the load combinations might be required.

Why is the total applied wind load on a semirigid diaphragm more or less than a rigid diaphragm?

The total length of windward and leeward edges may exceed the exposure length when the slab edge has a return (like a "U" shaped structure) and the diaphragm is semirigid. This leads to more total force being applied since all these edges are loaded based on the pressure, story height and mesh size.

The Report - Loads and Applied Forces lists both values to be clear:

Furthermore, when wind loads are applied to a meshed semi-rigid diaphragm only the windward and leeward edge nodes are loaded. if the applied deck does not extend to the slab edge overhang, then the program will fail to find the edges to load and the total applied load will then be less than it should be. It's imperative that the deck extend to the slab edge when using semi rigid diaphragms.

Additionally, when the diaphragm is semirigid, this can affects the building natural frequency which, in turn, can affect the wind gust factors and pressures and total forces. It may be better to manually input the structure frequency when using semirigid diaphragms.

How does sloped framing affect the wind loads?

The program currently applies the wind loads based on the simple rectangular area of the structure defined by the story data. Adjustments in the column and wall elevations do not affect the total applied wind loads at this time.

Use the Report - Exposure Boundaries to see a visualization of the exposed wind surfaces whenever there is some concern over the height or tributary width being used to calculate total story forces. For more on the effect of having sloped diaphragms in RAM Frame, see RAM Frame - Criteria - Diaphragms.

Can wind loads on open structures be generated?

No, when the program generates wind loads it always assumes the structure is fully clad all the way down to the ground level with one complete windward and leeward surface. The same exposure height is assumed on the windward and leeward surfaces.

For any other condition and where rigid diaphragms exist, "User defined story forces" should be used. User defined story forces are defined in RAM Frame under Loads - Load Cases by selecting "User defined story forces" from the drop down menu to the right of the toggle for wind loads. When there is no rigid diaphragm use "Nodal loads." Nodal lateral loads are defined in the Modeler in the Elevation view.

The program generated wind loads are not completely accurate for any of the situations below.

• open structures,
• partially exposed structures,
• structures with different exposure heights on the windward and leeward surfaces
• structures with multiple windward surfaces (e.g. a "U" shaped plan),
• structures with a stepping foundation.
• upper portion of a structure modeled in a two-stage lateral analysis with lower portion omitted

Is cantilever or prying action from pressure on a parapet considered?

No, the force to the top level diaphragm is equal to the pressure on the parapet times the parapet area plus the pressure on the top half of the story below. The additional reaction to the roof that results from cantilevering the parapet wall up from the level below (prying force) is not accounted for. The Report - Exposure Boundaries helps to clarify exactly what building surface areas are considered in the wind load calculations. 

Can the entire RAM SS model be elevated like a structure on top of a podium to get the correct wind pressures?

Starting in version 17.02, you can build an elevated first story to place the rest of the model upon. This level could be as simple as a set of lateral columns under the columns above, or a set of lateral walls to support everything above. Make the columns vertically very stiff. Then set this first level to the ground level for Analysis, while leaving the ground level for Wind Load Generation "At Base".

Note, in the wind load definition there is a property for Mean Roof Height which is taken as the top story height be default. The user can override this value which will alter the pressure, but when calculating the windward pressure, the original story heights above ground are still used. In other words, the program is not adjusting Kz windward based on the input mean roof height. 

If you actually raise the structure, by adding a blank first story with height = h1,  it will elevate the structure and raise the wind pressure correctly, but it will also assume that the exposed height of the lowest level diaphragm is larger by h1/2 giving you too much force on the lowest framed level. This can be confirmed using the Loads and Applied forces report and the Exposure Boundaries report.

Thus it's better to model something physical for the lower supporting structure. 

Alternatively, it may be easier to just apply "User defined story forces" for the wind.

Latest Major and Minor Versions

• RAM Structural System CONNECT Edition v17.02.00 SES Release Notes

Previous Versions

• RAM SS V12.1.X Release Notes
• RAM SS V13.0 Release Notes
• RAM SS V13.0.2 Release Notes
• RAM SS V13.0.3 Release Notes
• RAM SS V13.0.4 Release Notes
• RAM SS V14.00 Release Notes
• RAM SS V14.00.01 Release Notes
• RAM SS V14.00.02 Release Notes
• RAM SS V14.00.03 Release Notes
• RAM SS V14.00.04 Release Notes
• RAM SS V14.02 Release Notes
• RAM SS V14.02.01 Release Notes
• RAM SS V14.02.02 Release Notes
• RAM SS V14.03 Release Notes
• RAM SS V14.03.01 Release Notes
• RAM SS V14.03.02 Release Notes
• RAM SS V14.03.03 Release Notes
• RAM SS V14.04 Release Notes
• RAM SS V14.04.01 Release Notes
• RAM SS V14.04.02 Release Notes
• RAM SS V14.04.03 Release Notes
• RAM SS V14.04.05 Release Notes
• RAM SS V14.04.06 Release Notes
• RAM SS V14.04.07 Release Notes
• RAM SS V14.05.00 Release Notes
• RAM SS V14.05.01 Release Notes
• RAM SS V14.05.02 Release Notes
• RAM SS V14.05.03 Release Notes
• RAM SS V14.06.00 Release Notes
• RAM SS V14.06.01 Release Notes
• RAM SS V14.06.02 Release Notes
• [[RAM SS V14.07.00 Release Notes]]
• [[RAM SS V14.07.01 Release Notes]]
• RAM SS V15.00 Release Notes
• RAM SS V15.01 Release Notes
• RAM SS V15.02 Release Notes
• RAM SS V15.03 Release Notes
• RAM SS V15.04 Release Notes
• RAM SS V15.05 Release Notes
• RAM SS V15.06 Release Notes
• RAM SS V15.07 Release Notes
• RAM SS V15.08 Release Notes
• RAM SS V15.09 Release Notes
• No RAM SS V15.10
• RAM SS V15.11 Release Notes
• RAM SS v16.00 Release Notes
• RAM SS v16.00.01 Release Notes
• RAM SS v16.01.00 Release Notes
• RAM SS v17.00.00 Release Notes
• RAM SS v17.00.01 Release Notes
• RAM SS v17.02.00 Release Notes

Can I start a model with a template?

A new model created using File - New has all the criteria and defaults set based on the information in the Ramis.ini file, which can be configured using Ram Manager - Tools - Ram Defaults utility. For more on this see: Ram SS Installation FAQ 

Alternatively, you can take any model that you have set up the way you like, delete all the stuff in the model (layouts, grids, stories) and then use that like a template to start new models using File - Save-as. Some users prefer this approach to starting new files based on the defaults utility settings because you can

• Create several templates for different building types, design codes, etc.
• Pre-populate the template models with standard concrete beam and column shapes, common deck and load properties, etc.

See also: Do You Like to Start With a Template?

What is the Working directory?

A RAM Structural System model file (e.g. filename.rss) is literally a Zip file and within any .rss file you should find many component files of the same name with a wide range of extensions including (but not limited to) .b3d, .ram and .uid. These files are extracted from the model file and put into the working directory when opened in RAM Manager (in older versions of the program all of these files were simply saved together in the model directory). In some cases a zip repair utility can be used to open a .rss or .backup file that won't otherwise open.

For this reason the working directory should always be on the local drive and in a place in which the “user” has administrative rights. It’s also important for the user to have the rights to add, modify and delete files in the model directory. Furthermore, we recommend that users exempt the working directory from any virus scanner software. If the virus scanner stops the generation or modification of files in this folder it could cause the program to perform slowly or fail to save model changes. 

Note: the working directory is set the first time the program is run, to confirm or edit the working directory location go to C:\ProgramData\Bentley\Engineering\RAM Structural System and double click the Ramis.ini file (c:\windows\ramis.ini prior to version 14). This should bring up the Ramis.ini file in Notepad (or other text editor). Look for the line that begins

working=path to working directory.

You can edit this path to the working directory here. Spaces are allowed as are references to mapped drives, but for the reasons mentioned above, a local drive should be used.

Also in the [Directories] section you will find the paths for other installation directories like the Tables folder where the program looks for all the tables and the default reports directory for saved reports.

For more information on the contents of the Ramis.ini file, refer to the RAM Defaults Guide [TN] and the RamSS Installation FAQ. 

Are RAM Structural System models backwards compatible?

Regretfully Ram SS models are not backward compatible. Typically with each major release there are changes in the model data base format. Once models are converted to the new version they can no longer be used in prior versions.

When a model is converted a backup of the original file is automatically created in the same folder with the same name and appended with the original file version, e.g. MyFile_Orig_14_7.zip, in case there is any need to revert to the prior version.

Note, though version 14.06.01 is generally considered a minor release, file conversion from version 14.06.00 is required. See the 14.06.01 Release Notes for details.

Is there a maximum file size?

As of version 17, the Ram Manager utilizes a 32 bit zip control to compress the working files into a single zipped .rss file. This control is limited to 4GB. Should you have a file that exceeds that limit it may not save completely, giving the "Could not unzip . . . . . " error message. At that point you should Save as Archive to save the input without results and then try to reduce the file size, e.g. by increasing the mesh size or changing criteria to not save some of the results, e.g. wall stresses. 

When I open a model I get a warning, “This file appears to be currently opened by: User Name…”

If the listed user really is in the file, they need to exit the program normally to release the model so that you can open it (RAM SS models do not allow for concurrent use).

If that user is not currently in the file or unavailable, you should navigate to the directory where the model is saved and look for a file of the same name with the file extension “.usr”. This is a lock file that was created when the user last accessed the model. The .usr file is normally deleted when the model is closed, but if the program terminated irregularly, the file might persist. Simply delete the .usr file and the .rss file can then be opened.

When I open a model I get a warning, “A temporary backup file has been found for this database (path to file), which indicates that the program abnormally terminated…”

If you select the “Most Recent Database” you are telling the program to reload the files from the working directory which should be the same as they were just before the crash. In such cases, we suggest that you immediately use the file – save-as feature to turn this into a new model file.

Clicking “Backup Database” deletes the working files and restores the files from the saved model whenever it was last saved. “Cancel” leaves everything alone. If your not sure when the last save occurred, click cancel and then check the modified date of the model file through an explorer window before returning to pick either option.

Starting with version 14.06 an additional backup file is created for models that crash and are then re-opened. A copy of the rss file with the extension .ssr is created if you reopen a model that is already expanded to the working directory indicating a previous crash or incomplete closure. Like the .backup file, the .ssr file can be renamed with a .rss extension to restore that version of the file.

When I open a model I get a warning, “Could not delete RAM model: filename. Working files in directory \path to working directory\, please use the explorer to delete these files.”

There are two situations where this message might appear. The first is a restriction to the working directory or the model directory. The user needs to have the rights to add, modify and delete files from both locations (preferably administrative rights). See above for more on the working directory.

The second problem is a corrupt or partial model file. If the model file is missing any of the critical component files it will not open correctly and the same message will appear. To investigate, rename the model file, changing the extension form .rss to .zip and double-click it to see what inside. You should see a series of files all with the same name but with a wide range of extensions including (but not limited to) .b3d, .ram and .uid. When a model file does not contain a complete set of component files it is unusable. It is a mystery what causes a file to become this way, but it seems that something must have interrupted the save process. A virus scanner may also be responsible.

At this point the backup file should be used, see below.

When attempting to load a module, I receive a message that a "File already exists" with a db.sdf extension.

The error may be caused by an installation issue with a database component included with RAM Structural System. Removing and reinstalling the component may resolve the issue. To do this, perform the following steps:

1. Open the Control Panel from the Windows Start menu (Windows XP/Vista/7) or Windows Start screen (Windows 8).
2. Open Add or Remove Programs (Windows XP) or Programs and Features (Windows Vista/7/8).
3. If running RAM Structural System 14.06.00 or earlier, remove Microsoft SQL Server 2005 Compact Edition. If running RAM Structural System 14.06.01 or later, remove either Microsoft SQL Server Compact 4.0 or Microsoft SQL Server Compact 4.0 (x64).
4. Locate and open the RAM Structural System installer (e.g. ramm14060100en.exe or ram6414060100en.exe), often stored in the Downloads folder.
5. Click the Install button next to Microsoft SQL Server Compact Edition*, and proceed through the installation to restore the component.

* In RAM Structural System version 16 there is no longer a separate option to install the SQL Server only, but repairing the installation should replace it.  The same can also be obtained directly from Microsoft.

In rare cases, we are seeing initial settings for some computers (Windows 10) are causing this issue. If all of the above steps do not resolve the issue, please create a service request, attach the machine.config file with the service request and give the path of it.

See also [[Unable to find the requested .NET framework data provider]]

Something is wrong with my model file, is there an automatic backup?

Yes, in the directory where the model file is saved, there should be another file of the same name with the extension, “.backup”. Rename this file something.rss (you won’t be able to use the same name of the original model file unless you move or rename it first). The backup file should be a complete version of the model from the previous time it was saved. If your not sure when that was, simply check the modified date.

Note: when backing up your own files, it is only the .rss model file that you need to save. When restoring backup files or old files from a backup CD or tape, make sure the files are not read-only. If you attempt to open a RAM model that is read-only, you will get another warning, “Failed CopyRssFileToWorkingDir:…”, “Failed DeleteRssInWorkingDir:…”, or “File error 2,6”.

How can I reduce the size of my files?

Starting in version 17.01, use Ram Manager - File - Save as Archive to create a backup file without analysis results. The save-as dialog will appear and the default file name with match the original with the version and date added as a suffix.

For older versions, see below:

A RAM Structural System model (file.rss) is already a compressed zip file, but the size of that file can become quite large, especially when the analysis and design results are saved with the file. In RAM Manager under the File menu is an option to ZIP the model. When zipping models using that command you will have the opportunity to purge the model of some unnecessary results (which can be regenerated later just by running the file again). The optional results are:

• Include the RAM Frame Wall Forces results
• Include other RAM Frame Analysis results
• Include RAM Concrete Analysis results
• Include the RAM Concrete Column Interaction Surfaces
• Include the RAM Concrete Shear Wall results.

See Also

[[Unable to find the requested .NET framework data provider]]

RAM Defaults Guide [TN]

RAM SS File-Open Troubleshooting [TN]

RAM Table Editing [FAQ]

Ram SS Installation FAQ 

I do not see any unit for the temperature load. Should I specify it in Degree Centigrade or Degree Fahrenheit ?

The unit of temperature loading should be consistent with the value of ALPHA that is specified as part of the DEFINE MATERIAL command. If your base unit setting is Metric, then the material properties including ALPHA would be in metric units ( so ALPHA would be in /deg C). In that case you would define the temperature rise/fall in degree Centigrade units. Otherwise if your base unit setting is English, then the material properties including ALPHA would be in English units ( so ALPHA would be in /deg F). In that case you would define the temperature rise/fall in degree Fahrenheit units. So you need to check the Base Unit Setting and the Alpha value defined in your file and then specify the temperature loading accordingly.