How can I evaluate an existing composite beam?

Using the Process - View/Update command, select the beam in the model. Change the selected member size, set the stud number to the desired value and click Analyze. Then click Update Database when finished.

If the existing stud count is insufficient to achieve 25% composite action (or the code minimum), go to Criteria - Stud Criteria and for the last option, select to "Use Composite section properties".

Note: the program will never optimize a member with less than 25% composite action (US codes), but you can reduce the number of studs and evaluate this way.

Can I lock or freeze all the beam designs?

Yes, once the designs are correct, use the Process - Freeze Design command to freeze the designs for some or all of the beams. This is often a good idea once construction documents for the project have been released.

The same command can be found in other modules, too.

Why are my composite beams being designed as non-composite members?

Beams that have been defined as composite, may be designed as non-composite for the following reasons:

• Non-composite deck
• Opening or exposed beam 
• Cantilever 
• No load

Non-composite deck: Composite beams will be designed as non-composite if the deck on both sides of the beam is non-composite for any portion of the beam span.

Opening or exposed beam: A beam that spans through an opening or penetration or for which there is a portion supporting no deck, such as an inset beam, will be designed as non-composite. Some times it is desired to design inset beams as composite. In order to do this, you can add a short beam from the column to the perimeter beams at an angle (say 45 degrees). Then define the slab edge so that it follows along these short beams, going out and around the perimeter column. That way, the entire beam is covered by the deck and it can be designed as composite (see below).

Cantilever: If the negative bending moment at the support of a cantilever beam is greater than twice the positive moment of the back span, the beam will be designed as non-composite. When a cantilever beam is designed compositely, the program determined number of studs should all be placed in the back-span. Note, for some codes no negative moment is allowed for composite beam design and in those cases a cantilever will always result in non-composite design.

No Load: If there is no load on the beam it will be designed as non-composite. This is sometimes a result of accidentally orienting the deck in the wrong direction such that the infill beams are not loaded.

Note: once a beam has been designed as a non-composite member, the composite flag for the beam will be set to non-composite. You have to go back to the Modeler and use the layout - beams - change properties command to turn it back into a composite member.

Why is the unbraced length reported less than the maximum unbraced length?

The program evaluates bending for each of the various unbraced segments of a beam along with the maximum moments in that segment. The design might be controlled by a shorter unbraced segment with larger moments, or it might be controlled by a longer unbraced segment with smaller moments.

The design report shows the critical condition and indicates where from the left end the critical case occurs.

Can I turn off the pattern loading on beam cantilevers?

Regretfully, not at this time. Live loads are always consider to act on the cantilever, on the back-span or on the entire beam, whichever condition provides the most conservative design for shear, bending and deflection. This is true even for snow loads which can be overly conservative. Only dead loads are not subject to patterning.

Can I turn off Camber on specific beams?

The Criteria - Camber controls whether to camber or not camber composite beams or non-composite beams for the whole model. In cases where you want no camber on specific beams consider adding a special deflection criteria with an initial deflection limit equal or less than the minimum camber and assign that deflection criteria to the beam in question: 

Can I customize the load combinations used in RAM Steel Beam?

Regretfully, not at this time. The load combinations used in RAM Steel are internal to the program and cannot be modified.

See Section 10.3.11 in the RAM Steel Beam Manual for a list of combinations used for each design code.

Note that floor live load and snow or roof live loads are combined and applied as a single live load. Some building codes, such as IBC, permit a reduction (0.75 factor) for combinations including two or more transient loads. RAM Steel uses the combination 1.0 DL + 1.0 LL (effectively, 1.0 DL + 1.0 LL + 1.0 SL). Using the reduction noted above, a load combination of 1.0 DL + 0.75 LL + 0.75 SL is permitted. If the IBC is selected for the code for load combination generation in RAM Frame, 1.0 DL + 0.75 LL + 0.75 SL and not 1.0 DL + 1.0 LL + 1.0 SL. This can cause some design differences for beams designed in RAM Steel Beam versus RAM Frame.

Can I override the unbraced length of a steel gravity beam?

In cases where you want the unbraced length to be reduced you can add brace points in the Modeler using Layout - Beams - Brace points. Alternatively adding additional short beams framing into the beam in question will brace the top and bottom flange at those locations. Use joists where you want only the top flange braced.

In cases where you want the program to use a longer unbraced length, for example where a beam is set higher than the deck in reality, set the Criteria - Design Criteria - Unbraced length so that neither deck perpendicular nor parallel to the beam braces the top flange. Since it's a global criteria it will affect all beams, however, so you might have to set the criteria this way and check the one beam, freeze the design, and then check the rest using the preferred criteria.

Alternatively, you could add a long penetration (Modeler - Layout - Slab - Slab Penetrations) along the beam covering most of the span.

Why are my beams being designed per the Canadian (or British) code with a Design Fy (or py) less than the Nominal yield stress assigned in the Modeler?

Please review the Ram Manager manual, section 2.4.7 Canada Parameters, 2.4.8 BS 5950 Parameters and the Ram Steel Beam manual section 10.4 Design Yield Strength.

To summarize, When using either of these codes for design, the steel material type for each type of structural member must be determined from a table. This steel type is combined with the nominal yield strength assigned to each individual member in the model to determine the steel grade and the design yield strength of the section.

For example, a section of type W with a nominal Fy of 350N/mm2 is assigned a steel grade of 350W. But, a nominal Fy of slightly less than 350 will result in a steel grade of 300W. Consequently, assigning a yield stress of exactly 50 ksi while using English / Imperial units, will result in a steel grade of only 300W being used, since 50ksi = 344.7 N/mm^2 which is less than 350.

Specifying a nominal Fy or material type that has no matching steel grade will result in a design yield strength of 0.0 and no grade assignment.

In the Ram Manager under Criteria - Canada Parameters (or BS 5950 Parameters) where the specific grade for various section types can also be specified.

For the example above, if the Material type A572/A992 is selected, then the beam will be designed with a Design Fy=50ksi

 The same is also true when using Ram SBeam as explained in the manual for that program.

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!

Problem Description

The error message "There has been an error designing one or more section cuts. Internal error designing cut(s)" is displayed during the design of one or more wall design groups in RAM Concrete Shear Wall.

Steps to Resolve

This error may be associated with very short wall segments (6" or less) as shown below:

To resolve the problem, delete the small wall segments and then delete and remodel the section cuts when returning to RAM Concrete Shear Wall.

See Also

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

British Sections designed, in RAM Frame, in accordance with BS EN 1993-1-1:2005, can, depending on the initial section size assigned, be classified as Class 4 in accordance with section 5.5 of this standard. As a reminder, the role of cross section classification is to identify the extent to which the resistance and rotation capacity of cross-sections is limited by its local buckling resistance.  

Four classes of cross section are defined in BS EN 1993-1-1:2005 as follows:

Class 1 -  cross-sections are those which can form a plastic hinge with the rotational capacity required from plastic analysis without reduction of the resistance.

Class 2 - cross-sections are those which can develop their plastic moment resistance, but have limited rotational capacity because of local buckling.

Class 3 - cross-sections are those in which the stress in the extreme compression fiber of the steel member assuming an elastic distribution of stresses can reach the yield strength, but local buckling is liable to prevent development of the plastic moment resistance.

Class 4 - cross-sections are those in which local buckling will occur before the attainment of yield stress in one or more parts of the cross-section.

For a member subject to both bending and axial compression as shown below, the critical section checks may occur at the beam ends or at the point of contra flexure where the beam is subject to compression only:

The above continuous beam comprises two spans, one 6.0m and one 4.0m. The 6.0m span will be considered for this example.

It should be noted that all UB sections which are classified as Class 4 when subject to a compressive force only, that the section classification is controlled by the web dimensions. This is confirmed in pages B – 62 and B – 63 of SCI Publication P 363.

RAM Frame does not check the design capacity of Class 4 sections in accordance with the requirements of BS EN 1993-1-1:2005 and this article outlines how users can perform a hand calculation to verify the adequacy of a Class 4 section.

Assume the section being designed is a 457x191x67 UB, its properties for section classification are:

Overview

Podium slabs are concrete transfer slabs supporting multiple levels of wood or steel framed superstructures above. This popular framing system can be analyzed and designed using RAM Structural System and RAM Concept. The purpose of this tech note is to discuss issues and commonquestions relating to the modeling and design of this system using these programs.

Modeling Options

Two common options for designing this type of structure include:

1. Use a two-stage analysis in which the upper portion and lower portion are designed as separate structures in RAM
Structural System. See ASCE7 12.2.3.2 for details.

2. Model the entire structure in one model in RAM Structural System.

Regretfully, there is not an automated two-stage analysis feature in RAM Structural System. This means that loading from one model needs to be manually entered in the second. One possible work around:

1. Model and analyze the upper portion in RAM Structural System with a mat foundation.
2. Import the mat foundation into RAM Concept.
3. Add columns  to convert the model to an elevated slab.
4. Amplify imported loads to satisfy ASCE7 12.2.3.2.
5. Add lateral and additional gravity loads on lower portion in Concept.
6. Analyze and design.

With this approach, foundations will need to be designed manually using the analysis results from RAM Concept. There is not a way to import them into RAM Foundation for design. Also, the lateral analysis for the lower floor is done in RAM Concept. This will not work well if there are multiple concrete levels below the upper portion.

RAM Structural System Tips

In RAM Modeler, live load reduction percentages should be modeled manually for columns and walls supporting two-waydecks. See the following web page for more information on using two-way decks in RAM Structural System:

RAM SS Two-Way Decks

It is important that all walls fit on the podium slab. If any wall extends outside the podium slab edge, unintended foundation supports can be added in the model. The reaction at the foundation support would not be transferred to the podium slab. This problem most often occurs at walls that are skewed to the global x or y axes and the slab edge segment is modeled continuous past the wall end. To prevent this from occurring it is best to snap slab edge segments directly to walls ends near the slab boundary. Displaying reactions in RAM Frame (Process – Results – Reactions) is a good way to check for unintended foundation supports. See reaction points circled in the screenshot below for an example of an unintended foundation support.

In RAM Frame, pseudo-flexible or semirigid diaphragms are the best options for models at wood framed levels. If walls are skewed relative to the global x and y axes in plan, then semirigid diaphragms should be used. See the following web pages for more discussion on these diaphragm types.

RAM SS Pseudo-Flexible Diaphragms

RAM SS Semirigid Diaphragms

In RAM Frame, the in-plane flexural stiffness of lateral walls above the podium level is always considered. As a result, the walls will be meshed with the podium slab and act as a stiffening element. This can produce significant moments at the base of the transfer walls. In most cases, loads are assumed to transfer directly from the wall to the slab, ignoring the wall stiffness above.

In RAM Concrete, there is an option to ignore the stiffness of walls above the slab. This option is located in the Analysis Criteria dialog in RAM Concrete – Concrete Analysis mode (Criteria –Analysis). Check the box for “Ignore Wall Stiffness on Above Story” to ignore the stiffness of the walls above.

More discussion on walls in RAM Structural System can be found on the following web page;

RAM SS Wall FAQs

In RAM Concrete, skip live load cases can significantly increase analysis time. Many models with podium slabs containlevels with many “other” type beam members. If the “Skip-Load the Live Load on Non-Beam Line Beams” is checked in RAM Concrete Analysis – Analysis – Criteria, the program will skip the live load on all of the “other” beams. Typically, this is not intended and the box can be unchecked.

RAM Concept Tips

RAM Concept offers three options for import of gravity forces: forces from RAM Steel, forces from RAM Concrete, and forces from RAM Frame. Generally, it will be best to use the RAM Steel forces as the first preference when importing. In RAM Steel, load is distributed to members based on a simple tributary area. The wall stiffness is considered in both RAM Concrete and RAM Frame. The transfer wall moments may be significantly higher if RAM Concrete or RAM Frame forces are selected with a higher priority than the RAM Steel forces.

When importing gravity forces from RAM Steel, line and point loads are converted to an equivalent load at the base of the wall assuming the wall is a rigid element. Point loads that are eccentric to the center of the wall will translate to moments and a non-uniform load at the base of the wall. Segmentation of the wall will affect the transfer wall load that is imported into RAM Concept. See example below:

Each wall is 20 ft long. The wall on the left is modeled with one wall segment. The wall on the right is modeled with two wall segments; there is a 1-ft segment near the end of the wall. Each wallhas a 10 k/ft live load and a 10 k point load located 1-ft at the wall end (same point where the right wall is segmented).

The following line loads are imported into Concept:

The line load on the left has a magnitude of 11.8 k/ft at one end and 9.15 k/ft on the other. These loads are calculated from:

10 k/ft + (10 k)/(20 ft)  +/- (10 k)*[(20 ft/2) - 1 ft)]/[(20 ft)^2*6]  = 11.85 k/ft and 9.15 k/ft

The line load on the right is divided into two segments, representing the 1-ft wall segment and the 19-ft walls segment.

The 1-ft wall segment has a magnitude of -0.008333 k/ft on one end and 29.99 /ft on the other. These are calculated from:

10 k/ft + (10 k/2)/(1 ft)  +/- (10 k/2)*[(1 ft/2)]/[(1 ft)^2*6]  = 30 k/ft and 0 k/ft

The 19-ft wall segment has a magnitude of 11.05 k/ft on one end and 9.473 k/ft on the other end. These loads are calculated from:

10 k/ft + (10 k/2)/(19 ft)  +/- (10 k/2)*[(19 ft/2)]/[(19 ft)^2*6]  = 11.05 k/ft and 9.473 k/ft

In this example, modeling the wall in one segment will result in more accurate loads in RAM Concept.

For elevated slabs, live loads are always imported as unreduced live loads. If you would like to account for live load reduction you can either reduce the loads manually after importing or manually assign live load reduction parameters in the Live Load Reduction tab of the Span Segment Properties dialog. See below:

For mat foundations, reducible live loads are reduced when they are imported into RAM Concept. If you are using a two-stage analysis, set the Code for Live Load Reduction to “None” after importing to ensure the loads are not reduced twice.

See Also

RAM SS Two-Way Decks

RAM SS Pseudo-Flexible Diaphragms

RAM SS Semirigid Diaphragms

Product TechNotes and FAQs

RAM SS Wall FAQs

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!

Release Date: January 23, 2014

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.

Important Notices

Version 14.06.01 automatically converts databases created in previous versions to the new database format. Databases opened and saved in V14.06.01 cannot be opened in previous versions, including V14.06. 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.

A benefit of the new licensing procedures is that it is not necessary to be connected to the internet at the time the program is run, in order to run the RAM Structural System, as long as that machine has accessed the Bentley license server and verified a valid license within the preceding 14 days. If a machine has not connected with the license server within the preceding 14 days, the first time this occurs a 14-day trial license will be activated allowing the program to continue to be available for that period. Subsequently, it is necessary to be connected to the internet so that a valid license can be verified with the license server. This same trial license capability allows a user to try out any of the RAM Structural System modules for 14 days, even if no license has been purchased for those modules. If you want to evaluate a module, merely invoke it and the 14-day trial period will begin.

Installation Instructions

This version can be found on the Bentley SELECT Services Downloads and Updates web page at: http://selectservices.bentley.com/en-US/Support/Downloads+And+Updates/

Select “Search Downloads” and log in using your User Name and Password. Perform a Search by searching for the “RAM Products”, and select the latest version of the RAM Structural System.

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.

Member Forces Text Display

Two new controls for the display of the text have been added to the Process – Results – Member Forces command and the Process – Results – Member Forces Envelope command. The number of decimals to be displayed can be specified, and the location of the placement of the text along the member can be modified. These options provide means for eliminating problems with overlapping text in the display.

Beams Through Slab Penetrations

The purpose of Slab “Penetrations” is to model the impact that penetrations through the slab (for mechanical ducts, for example) have on the effective flange width for composite beam design. If a penetration is modeled adjacent to the beam, the effective flange width on that side of the beam is limited based on the location and distance out to the penetration. If a penetration is modeled directly over the beam (the beam cuts through the slab penetration) the program designs that beam as noncomposite. Previously for this condition the program did not consider the effect of the penetration on the unbraced length; the program now considers such beams to be unbraced through the length of the penetration (or longer if the deck doesn’t brace the flange). Note that since penetrations are generally quite small, this change is not likely to have any effects on the design, but this enhancement has been made for completeness, in the event that the beam size is small or the penetration is large, such that the unbraced length through the penetration controls the design.

Maximum Stud Spacing Warnings

In the View/Update command in the RAM Steel Beam module the number of studs required for Full Composite and for Partial Composite are shown. The number of studs required for Partial composite may be controlled by any of several requirements, including strength, deflection, minimum percent composite, maximum stud spacing, etc. The user has the ability to specify any value of studs for Actual, and then have the program Analyze the beam for that stud configuration. This number should almost never be specified as less than the value shown for Partial, otherwise some criteria or Code requirement will be violated. In such cases the program provides warnings when strength or deflection requirements are not met, but previously the program did not give a warning if the user specified a fewer number of studs that violated the maximum stud spacing requirements. Warnings have now been added indicating when the user-specified studs violate the code-mandated or user-specified maximum stud spacing. This change does not change any designs, it merely clarifies the acceptability of user-specified studs.

Stud Length

When specifying composite deck properties for use with AISC design the Modeler limited the stud length to hr+3". This is no longer a requirement of the AISC Specification so the limit was removed. This change has no impact on design. The limit was removed; longer studs can be specified (but note that longer studs don't impact the stud capacity). For ASD 9th and LRFD 3rd the equation limiting the value of stud length used to hr+3" is enforced.

ASC Deck Profiles

Some deck profile properties have changed for decks manufactured by ASC, and these changes were updated in the deck properties table RAMDECKS.DCK. Specifically, the depth of ASC 2W is now 2-1/8” instead of 2”, and ASC N-24 deck has been replaced by ASC N-32 deck. To take advantage of these changes for existing models that use either of these profiles, re-specify the Composite Floor Deck Properties in the PropTable – Decking command in the Modeler; otherwise the program will continue to use the old values.

CAN/CSA S16-09 Shrinkage Deflection

In the Shrinkage Deflection calculations for S16-09 Section 17.3.1(c) there is an ns term. The program was using the value of nt specified by the user in Criteria - Canada Parameters, but that wasn't apparent to the user, and the range of values for nt used by S16-01 is different than that used for ns by S16-09. The program has been enhanced to now calculate the value of ns when S16-09 is selected as the design code. The Beam Design report has been modified to list this value.

Concrete Shear Wall Performance

Some modifications were made that significantly enhance the performance (speed) of the 64 bit version of RAM Concrete Shear Wall module.

RAM Frame Precision

Changes were made in RAM Frame to improve the precision of the analysis. Most models will see little or no changes to the results. Models with dynamic load cases may see some nominal changes to member design forces. Re-invoke the Analyze command on models that were previously analyzed with an earlier version of the program to take advantage of this improvement to the precision of the analysis results.

Reduced Beam Sections

In RAM Frame, in the Analysis of beams with RBS sections, if the option to Use Reduced Section Properties in Analysis was selected, the program took the simplistic approach of establishing the intermediate nodes along the beam starting with a node a distance “a” from the end of the Rigid End Zone as specified by the user. This has been enhanced so that regardless of the Rigid End Zone selection set by the user, the intermediate nodes along the beam now start at a distance “a” from the face of the column. This is unlikely to significantly affect the results, but is more accurate. The documentation has also been updated to indicate this change.

DXF Layer Names

While some CAD programs allow spaces in layer names, AutoCAD and MicroStation do not (when imported as a .DXF file). If a DXF file is generated with a layer name specified by the user that includes a space, the space is automatically replaced with an underscore (‘_’) so that the DXF file is compatible with AutoCAD and MicroStation.

Error Corrections

Some program errors have been identified and corrected for Version 14.06.01. 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 apologize for any inconvenience this may cause.

Defaults Utility

CONSIDER ROOF LOADS*: Even if the option to "Consider Roof Loads" was selected as the default in the Defaults Utility, the option to "Consider Snow Loads" was used in new models. The opposite was also true.
Effect: The wrong option was set in new models and used in design if user did not change this setting for the model. If the desired option was explicitly selected for the model, the correct loads were used.

DXF COLUMN & FOOTING DXF: The DXF – Column & Footing command did not function.
Effect: Column and Footing DXF files could not be created.

Manager

RAM CONCEPT INTEGRATION: The RAM Concept file stored with the RAM Structural System model was accidentally deleted when converting from v14.5 to v14.6.
Effect: The file contained settings relevant to the interaction between RAM Concept and RAM Structural System. These settings were lost and had to be re-entered.

JOB NAME: If the user changed the Job Name and then did a Save As, the new Job Name was not saved.
Effect: Old Job Name, rather than the new Job Name, was saved with the database.

Steel Beam

FRAME BEAMS: The ability to perform the View/Update on Frame Beams and then update the database with updated sizes was recently added to the program. As a result of this change, if a floor type was used on two or more stories and the Frame beam sizes differed between levels, performing a Design All caused the Frame beam sizes to be changed to be the same as that of the beam in the top-most occurrence of the layout type.
Effect: Frame beam sizes may have been unintentionally modified.

SIZE LABELS: In some circumstances, the look up of a steel size in the Master steel table was case sensitive so, for example, the size w10x30 would not be found if listed in the master table as W10X30.
Effect: The largest impact came from models imported through Revit or ISM. User-assigned sizes were not found in the steel table so the design or analysis could not be completed.

CAN/CSA S16 COMPOSITE BEAMS WITH THIN FLANGES*: Investigations of thin flanged composite beams with stud diameters exceeding 2.5 times the flange thickness received no warning.
Effect: Although beam designs were correct and provisions of Section 17.6.5 were enforced during beam size optimization, investigated user sizes were not warned of flange thickness requirements per Section 17.6.5 of the CAN/CSA S16 specification when the stud diameters exceeded 2.5 times the flange thickness.

CAN/CSA S16-09 MAXIMUM STUD SPACING: The minimum of 4 times deck thickness or 600mm was used for the maximum stud spacing rather than 1000mm.
Effect: An incorrect maximum stud spacing was enforced, potentially resulting in more studs being called out than were necessary.

CAN/CSA S16-09 MINIMUM COMPOSITE: When S16-09 was selected the program limited the minimum composite to 0.50 rather than 0.40 as permitted in Section 17.9.4(a).
Effect: Designs may have conservatively called out more studs than required.

Steel Column

COLUMN LOADS*: If a wall was supported by columns below (rather than by another wall or a beam), the self-weight of any steel beams framing into the end of the wall was not transferred down to the supporting columns.
Effect: The column loads for columns supporting a wall did not include the self-weight of the beams framing in to the wall end above the column.

HANGING COLUMNS: When viewing the Column Design report for a hanger from the View/Update dialog, the self-weight of the hanger was, in some cases, calculated and reported incorrectly.
Effect: Dead load used to check the design was too high. The reported design was based on this dead load which resulted in overly-conservative results. Designs may be reported to have failed which would not have failed if the correct dead load had been considered. Note that the results displayed in the View/Update dialog, on the screen and in the column design report as issued from the Reports menu were correct; only the report issued from the View/Update View Results command was wrong.

CAN/CSA S16-09 COLUMN REPORT: For columns with axial compression and strong axis moment at the bottom of the column, the design report did not include a section on Strength.
Effect: Although column codes check were correct for all columns,  the report for columns with axial and strong axis moment at the bottom of the column showed sections for Member and Lateral Torsional Buckling (where applicable), and failed to show a section on Strength.

BASEPLATE DESIGN*: No failure warning was given if the required baseplate dimensions (due to column size and minimum edge distances) were larger than the size of the supporting concrete column/pier.
Effect: In that case, the baseplate dimensions were given as required for the column size and minimum edge distances, which exceeded the supporting concrete dimensions. The reports showed the correct design values and results, but no warning was given for this condition, even in some cases where the concrete was overstressed.

RAM Frame – Analysis

FORCE DIAGRAMS FOR DYNAMIC LOAD CASES: The Member Force diagrams for dynamic load cases may have displayed incorrect values at locations along the member.
Effect: Display error only. This error did not affect the member designs.

EUROCODE ENV1991-2-4:1995 WIND*: The story forces generated for the pre-standard Eurocode ENV 1991 wind were incorrect.
Effect: Incorrect design loads. (Note: the current implementation is the pre-standard, which has been replaced by EN 1991-1-4:2005.)

BRACE FIXITY*: If braces were not pinned, the program incorrectly handled the shears and moments in these braces when calculating and reporting reactions and building and frame story shears.
Effect: Reported reactions and story shears were incorrect if the model contained fixed-end braces. Error did not occur if the braces were pinned.

DIRECT SOLVER: For models with two-way decks and rigid diaphragms, the execution time to solve the system was longer compared to the previous version.
Effect: Excessive analysis time. In some cases, an insufficient memory issue occurred.

ANALYSIS LOG REPORT: The report did not properly include moments from walls when reporting equilibrium check results.
Effect: Report error only. Other reports and designs were not affected by this error

RESPONSE SPECTRA ANALYSIS*:  If a model included a two-way deck that was specified to be considered as a Pseudo-Flexible diaphragm, the program considered the full stiffness of the diaphragm both in-plane and out-of-plane in the analysis. As a result, the Pseudo-Flexible diaphragm was analyzed as if it were a Semirigid diaphragm for the Response Spectra load cases.
Effect: In an unusual set of conditions (response spectra analysis on a model with two-way deck specified as Pseudo-Flexible) the Dynamic response spectra load case results were not valid. Lateral and gravity load cases were not affected by this error.

DYNAMIC LOAD CASE REACTIONS: Incorrect moment reactions were reported in the Frame Reactions report for dynamic load cases.
Effect: The report listed incorrect moment values.

RAM Frame – Steel Standard Provisions

CANADA S16-09 SECTION 13.3.1*: An incorrect n value was used for Class H round HS and an incorrect value may have been used for square and rectangular HSS.
Effect: An incorrect n value may have resulted in unconservative designs of round HS and incorrect designs of square and rectangular HSS shapes.

CANADA JOINT CODE CHECK: The S16-01 and S16-09 Joint Code Check report listed incorrect capacities for Clause 21.3(b) when the '?' steel grade was specified for columns in the Criteria – Canada Parameters command in the RAM Manager.
Effect: The reported capacities for clause 21.3(3) were incorrect for columns assigned a steel grade of '?'.

CANADA S16-09 CODE CHECK SUMMARY: The summary report may have listed some incorrect controlling clauses.
Effect: Report error only, the designs listed in the report were correct but the controlling clause reference may have been incorrect.

RAM Concrete – Beam

BEAM DESIGN REPORT: The clear length and c-c length were incorrectly reported for stub cantilever members. For beams with extension cantilevers, the cantilever lengths were not reported.
Effect: Report error only.

RAM Concrete – Column

AUSTRALIA AS 3600-09: Using AS 3600-09, the column design report referenced Clause 8.25(i) which does not exist. This has been corrected to reference 8.2.5(a).
Effect: Design was correct, but code reference was wrong.

AUSTRALIA AS 3600-09*: Using AS 3600-2009, the number of legs reported in the Transverse tab of the V/U dialog may have been incorrect, and the concrete capacity in shear in the minor axis direction may have been underestimated.
Effect: Incorrect reporting of number of legs of shear reinforcement and of concrete capacity.

PMM DIAGRAM: When viewing the PMM diagram for a column design using any of the ACI codes, the compressive resistance (phi * Pn) shown in the diagram was sometimes marginally less than the actual calculated compressive resistance.
Effect: Not impact on designs or reports, the error was only in the diagram.

CONCRETE COLUMN SUMMARY REPORT: When designing to BS8110 or CP65, columns unreinforced for shear were reported to have a Ld/Cap ratio of "#1.J" instead of "N/A".
Effect: Report error only.

RAM Concrete – Shear Wall

COUPLING BEAM SHEAR*: When designing shear wall coupling beams, the wrong load combination may have been reported as the critical one for shear.
Effect: In rare case the wrong design shear was used in the design. When the error occurred, it was only with seismic load combinations, not wind load combinations.

RAM Foundation

PILE CAPACITY*: If the load on a pile exceeded capacity by 1% or less, the program accepted the pile cap design without warning.
Effect: In rare cases the design of pile caps may have been unconservative, by less than 1%.

LIVE LOAD REDUCTION ON GRAVITY WALLS: If the option was selected to get gravity wall forces from RAM Steel results, the forces for the Live Load case were not reduced.
Effect: Unreduced Live Loads on walls were always used in the foundation design.

RAM DataAccess

(Note: RAM DataAccess errors reported here only impact programs written by third parties that use the functions indicated; these errors had no impact on results in the RAM Structural System.)

SELF-WEIGHT OF GRAVITY COLUMNS: The IForces1.GetGrvColForcesForLCase() function included the self-weight of columns even when the self-weight option in RAM Manager was not selected.
Effect: The return value of the dead load for the column always included self-weight of the columns,  resulting in excess loads on columns.

RAM DATA ACCESS: ILayoutHorizBraces.Add() didn't work properly when the start and end coordinates were flipped.
Effect: Invalid data in the model after adding the horizontal brace.

The following Release Notes are provided as a reference by Bentley's Technical Support Group.

RAM Structural System

Latest Major Version

• [[RAM SS V14.06.00 Release Notes]]
• [[RAM SS V14.06.01 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 V14.05.04 Release Notes]]

See Also

Product TechNotes and FAQs

External Links

Structural Analysis and Design Products

1. In a DIRECT ANALYSIS, are the deflections for serviceability checks computed using the unreduced E and I values ?

2. What is the value that I have to enter for the FLEX parameter ? Also why does Taub change from iteration to iteration ?

1. In a DIRECT ANALYSIS, are the deflections for serviceability checks computed using the unreduced E and I values ?

By default STAAD uses the reduced E and I for calculating displacements. However in the section 5.37.5 of the
Technical Reference Manual ( titled Direct Analysis ), you will find mention of a parameter named REDUCEDEI which can be set to a value of 0, for the full E and I to be considered for computing section displacements.

2. What is the value that I have to enter for the FLEX parameter ? Also why does Taub change from iteration to iteration ?

The value you enter for the FLEX parameter is the value of Taub that is considered for the first iteration. Taub is a function of Pr/Py where Pr is the axial force in the member and Py the yield strength. Although Py (= AFy) cannot change but Pr changes between iterations because the axial force changes due to Pdelta effects (both large and small). The Taub will not see the effect of the change in Pr until later exceeds 50% of the yield strength. Once Pr > 0.5 Py, Taub values are no longer 1 but are calculated using the equation provided for Taub in the AISC code ( Appendix 7 in the AISC 360-05 & chapter C in AISC 360-10) .

Error or Warning Message

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Explanation

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1. XXXXXXX

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1. In the output file, I see the following message ** WARNING ** A SOFT MATERIAL WITH (1.0 / 1.750E+01) TIMES THE STIFFNESS OF CONCRETE ENTERED. PLEASE CHECK.
2. In STAAD.Pro, you are providing Steel, Concrete and Aluminum as standard materials with built-in default values. Why isn't timber included? I am looking for the Modulus of Elasticity and Density of Douglas Fir.
3. I am analysing a plane frame. I specify a prismatic section with IX. The analysis stops with the error message that I need to specify IZ. What is the need to specify IZ?
4. What is the purpose of the "member release" command? What is the basis for the terms MX, MY and MZ in this command?
5. Can you please explain the concept behind member offsets?
6. Shouldn't there be a way to set the MEMBER TENSION attribute once for the model and have the program always look back on that line for the list of members which have been assigned this property? Obviously, the same goes for MEMBER TRUSS.
7. The STAAD graphical interface is showing a steel column in my model in an incorrect orientation. I have checked my input file (and also by double clicking on the actual member) and all of my columns consistently start at the lower node and go in the +y direction, all have a beta of 0, and all have the same member property. I have the exact same data for this graphically-incorrect column as the one below it that shows up the correct orientation. Yet another column shows a slightly skewed column orientation as if I had assigned it something other than 0 or 90 degrees, and I know for a fact that I haven't done this. 
8. I have a beam member for which I have assigned a single angle from the American steel table. When I look at the member properties output for that member, the values that STAAD reports for moments of inertia Iz and Iy do not match the values I see in the AISC steel publication for that angle section.
9. I understand that one should use the REPEAT LOAD command and not the LOAD COMBINATION command when analysing a model for cases where the MEMBER TENSION or MEMBER COMPRESSION command has been used. Talking about load combinations, in Section 5.35 of the STAAD Technical Reference Manual, notes Item (2) mentions that the LOAD COMBINATION command is inappropriate for a PDELTA analysis, and that one should use REPEAT LOADs instead. This appears to be true for NON-LINEAR analysis also. Why? 
10. How to account for cracked section properties when modeling with concrete in STAAD.Pro ?
11. How can I apply master slave specifications between nodes in non global directions ? For example I have two nodes and I want to apply a rigid connection between the two nodes along a line joining those two nodes. The line is inclined to the global direction

1. In the output file, I see the following message

** WARNING ** A SOFT MATERIAL WITH (1.0 / 1.750E+01) TIMES THE STIFFNESS OF
CONCRETE ENTERED. PLEASE CHECK.

Please explain to me in plain English what StaadPro is trying to tell me.

STAAD checks to see if the E (Modulus of Elasticity) assigned to members and elements is comparable to the values of steel, aluminum, concrete or timber. If it falls below or above the range of these materials, warning messages similar to the one you encountered are displayed. This is done to notify the user in case he/she is not aware of this fact, or if he/she may have specified the value in an incorrect unit system.

If you believe that your E is specified correctly, you may ignore the message. Else, correct the number.

2. In STAAD.Pro, you are providing Steel, Concrete and Aluminum as standard materials with built-in default values. Why isn't timber included? I am looking for the Modulus of Elasticity and Density of Douglas Fir.

Unlike the 3 materials mentioned in your question, timber comes in several varieties, with each variety having its own unique set of material properties. Douglas Fir alone comes in several varieties, as explained below.

The American Wood Council and the American Forest & Paper Association publish a document called the "Supplement NDS for Wood Construction", 1997 edition. It provides design values for structural sawn lumber and glued laminated timber. There is also a category called Visually Graded Decking.

Under each category, Douglas Fir comes in various species or combination of species. Under each species, there are various commercial grades. Each of those grades have a unique value of E, ranging from 1000 ksi to 1900 ksi. If the category, species, and commercial grade is known, the E value can be read from the tables in this document.

The American Wood Council and the American Forest & Paper Association also publish a document called the "ASD Manual for Engineered Wood Construction". In the 1999 edition of this document, Table 8A, page 15 contains the specific gravity of Douglas Fir as ranging from 0.46 to 0.5.

3. I am analysing a plane frame. I specify a prismatic section with IX. The analysis stops with the error message that I need to specify IZ. What is the need to specify IZ?

For plane frames with no beta angle, what is needed is IZ, not IX. IX is the torsion constant. IZ is the moment of inertia about the Z axis. Members of a plane frame with a beta angle of zero will bend about the Z axis, which explains the need for IZ. They are not prone to twisting, and that is why IX is not needed.

Table 1.1 from the Technical Reference manual, which shows the properties required for various types of structures, is reproduced below.

4. What is the purpose of the "member release" command? What is the basis for the terms MX, MY and MZ in this command?

By default, STAAD assumes the connection between any 2 members to be fully capable of transmitting all 3 forces and all 3 moments from one member to the other. This is usually achieved in practice by moment resistant connections, such as between a concrete beam and a concrete column which are monolithically cast.

If you want the connection to be of the type which does not permit one or more forces/moments to be transmitted, use member releases. A shear connection is such an example. The degrees of freedom FX through MZ that you release are based on the local axis of the member at whose end the release is specified.

See section 5.22.1 and the figures in Section 1.19 of the STAAD.Pro Technical Reference manual for additional information.

5. Can you please explain the concept behind member offsets?  

 When creating a model consisting of beams and columns, generally, the START or END face of the member is assumed to be located at the nodal point. In other words, the distance from the respective node to the start or end face of the member is treated as zero. Thus, for example, if member 47 is defined as being connected between nodes 12 and 13, then, the start face of the member is located at node 12, and the end face at node 13.

 This assumption may not always reflect the true physical condition on the structure. For example, when a beam meets a column, the common node between the beam and column is usually defined as being at the shear center (centerline for symmetrically shaped) of the column.

But, physically, the start face of the beam is not at that node, but at half the column depth away from the node. One may choose to ignore this "shift" if the column depth is negligible in comparison to the span of the beam. However, if one wishes to take advantage of the high stiffness that the half-depth region of the column offers, he/she may consider this using the member offset command.

The member offset is a way of declaring that the region, whose length is defined by the offset, is a rigid zone. Hence, if the offset values in X, Y and Z coordinates are a, b and c, the length of that region is d=sqrt(a*a + b*b + c*c). The face of the member is then assumed to be "d" away from the node.

The member end forces that STAAD reports are at the face of the member, not at the node, when an offset is specified. If the offset is applied at the base of a column, then the member end force may not be equal in magnitude to the corresponding support reaction terms. If one is interested in checking static equilibrium based on the free body diagram at that support, the member end forces must be transferred from the member face to the support node taking into consideration the rigid link defined by the offset. 

6. Shouldn't there be a way to set the MEMBER TENSION attribute once for the model and have the program always look back on that line for the list of members which have been assigned this property? Obviously, the same goes for MEMBER TRUSS.

In fact, that is exactly what STAAD is designed to do already. There is no need to keep re-specifying the MEMBER TENSION command, unless you want to specify a different list of such members. So, specify it once for the first analysis, and you don't have to specify it again. Same goes for the MEMBER TRUSS command.

7. The STAAD graphical interface is showing a steel column in my model in an incorrect orientation. I have checked my input file (and also by double clicking on the actual member) and all of my columns consistently start at the lower node and go in the +y direction, all have a beta of 0, and all have the same member property. I have the exact same data for this graphically-incorrect column as the one below it that shows up the correct orientation. Yet another column shows a slightly skewed column orientation as if I had assigned it something other than 0 or 90 degrees, and I know for a fact that I haven't done this.

a - Is the graphical interface a reliable representation of my input?

b - If yes, can you think of some other possible sources of this particular error?

If you look at the coordinates of the columns which appear to be oriented in the wrong way, chances are that you will find the Z coordinate of the 2 ends to be different by a very minute value, such as 0.001. For example, one end may have a Z value of 5.999 while the other end may be at 6.000. If so, you could do the following to correct it. Select the Geometry-Beam page along the left side of the screen, and it will display the node coordinates in the tables on the right hand side. In those tables, make the necessary correction so both ends of the column have the same Z coordinate.

The potential cause of this difference in coordinates is the following. The program has something called a Base Unit system. You can find this by starting the program, and before opening any file, go to the File menu, select Configure, and see if it says "English" or "Metric". If the model you are going to create is in Metres and KNs, you ought to have the base units in Metric. If the model you are going to create is in Feet and Kips, you ought to have the base units in English. Mixing unit systems causes the program to perform internal unit conversions which can result in loss of digits because the built-in conversion factors have only upto 8 digits of accuracy.

In fututure versions of STAAD, there will be a feature which will enable you to select the "offending" column and make the Z coordinate of its 2 ends to be equal so it becomes truly vertical.

8. I have a beam member for which I have assigned a single angle from the American steel table. When I look at the member properties output for that member, the values that STAAD reports for moments of inertia Iz and Iy do not match the values I see in the AISC steel publication for that angle section.

The numbers reported in the STAAD output for Iz and Iy are the moments of inertia about the principal axes of the single angle. The values in the AISC publication that you are comparing them with are most probably the values about the geometric axes. That is very likely the cause of the mis-match.

9. I understand that one should use the REPEAT LOAD command and not the LOAD COMBINATION command when analysing a model for cases where the MEMBER TENSION or MEMBER COMPRESSION command has been used. Talking about load combinations, in Section 5.35 of the STAAD Technical Reference Manual, notes Item (2) mentions that the LOAD COMBINATION command is inappropriate for a PDELTA analysis, and that one should use REPEAT LOADs instead. This appears to be true for NON-LINEAR analysis also. Why?

Before we can explain why, we first need to understand a few facts about loads in STAAD. There are two types of load cases in STAAD : Primary load cases, and Combination load cases.

Primary load cases

A primary load case is one where the load data is directly specified by the user in the form of member loads, joint loads, temperature loads, element pressure loads, etc. It is characterized by the fact that the data generally follow a title which has the syntax

LOAD n

where "n" is the load case number. For example,

LOAD 3

MEMBER LOAD

2 UNI GY -3.4

JOINT LOAD

10 FX 12.5

LOAD 4

ELEMENT LOAD

23 PR GY -1.2

LOAD 5

TEMPERATURE LOAD

15 17 TEMP 40.0 -25.0

Combination load case

Here, the user does not directly specify the load data, but instead asks the program to add up the results of the component cases - which are defined prior to the combination case - after factoring them by the user specified factors. It is characterized by the title which has the syntax

LOAD COMBINATION n

where "n" is the case number of the combination load case.

LOAD COMBINATION 40

3 1.2 4 1.6 5 1.3

What is a REPEAT LOAD type, and Which category does is belong to?

A Repeat Load type is a Primary load case. That is because, when the program runs into this command, it physically creates the load data for this case by assembling together the load information from all the component load cases (after factoring them by the respective load factors) which the user wants to "REPEAT". Thus, when you specify

LOAD 10

REPEAT LOAD

4 1.4 5 1.7

STAAD creates a physical load case called 10 whose contents will include all of the data of load case 4 factored by 1.4, and all of the data of load case 5 factored by 1.7.
If we use the same data used in the definition of the primary load case above, STAAD internally converts the REPEAT LOAD case 10 to the following :

LOAD 10

ELEMENT LOAD

23 PR GY -1.68

TEMPERATURE LOAD

15 17 TEMP 68.0 -42.5

What is the difference between a REPEAT LOAD case and LOAD COMBINATION?

The difference lies in the way STAAD goes about calculating the results - joint displacements, member forces and support reactions. For a load combination case, STAAD simply ALGEBRAICALLY COMBINES THE RESULTS of the component cases after factoring them. In the example shown above, it

gathers the results of load case 3, factors them by 1.2,

gathers the results of load case 4, factors them by 1.6,

gathers the results of load case 5, factors them by 1.3,

and adds them all together. In other words, in order to obtain the results of load 10, it has no need to know what exactly is it that constitues load cases 3, 4 and 5. It just needs to know what the results of those cases are. Thus, the structure is NOT actually analysed for a combination load case. With a REPEAT LOAD case however, the procedure followed is that which occurs for any other primary load case. A load vector {P} is first created, and later, that load vector gets pre-multiplied by the inverted stiffness matrix.

[Kinv] {P}

to obtain the joint displacements. Those displacements are then used to calculate the member forces and support reactions. Thus, the structure IS analysed for that load case {P}.

Why should the difference in the way STAAD treats a REPEAT LOAD case vs. a COMBINATION LOAD case matter?

Normally, if you are doing a linear static analysis - which is what a PERFORM ANALYSIS command does - it should make no difference whether you specify REPEAT or COMBINATION. However, if you are doing a PDELTA analysis, or a NONLINEAR analysis, or cases involving MEMBER TENSION and MEMBER COMPRESSION, etc., it matters. That is because, in those situations, the results of those individual cases acting simultaneously IS NOT the same as the summation of the results of those individual cases acting alone. In other words,

(Results of Load A) + (Results of Load B) is not equal to (Results of Load (A+B))

Take the case of a PDelta analysis. The P-Delta effect comes about from the interaction of the vertical load and the horizontal load. If they do not act simultaneously, there is no P-Delta effect. And the only way to make them act simultaneously is to get the program to compute the displacement with both loads being present in a single load case. A REPEAT LOAD case achieves that. A COMBINATION load case does not.

10. How to account for cracked section properties when modeling with concrete in STAAD.Pro ?

There are two ways. One can directly enter the reduced values for the sections using the PRISMATIC option as shown next

…

UNIT IN KIP

MEMB PROP

11 TO 21 PR YD 21.0 ZD 16.0 IZ 4321 IY 2509

…

The YD and ZD represent the overall dimensions which are used by the software to calculate the properties that are not input directly by the user. The IZ and IY represent the cracked section properties. Using the GUI, one can do the same from within the General > Property page. Click on Define within the Property – Whole Structure window and define the properties using the General option as shown next

Alternately one can define the cracked section property from within the modeling mode, by going to the General > Spec page. From within the Specification - Whole Structure dialog box on the right, click on Beam button and there is the Property Reduction Factors tab in there. Using that one can assign reduction factors to properties like cross sectional area and moment of inertia as shown next

11. How can I apply master slave specifications between nodes in non global directions ? For example I have two nodes and I want to apply a rigid connection between the two nodes along a line joining those two nodes. The line is inclined to the global direction.

The master slave specification is a method to model certain linkages between a control point (called a master joint) and a set of nodes (called slave joints) that are connected in the physical structure to the master joint through those linkages.

Those linkages cause the displacement of certain degrees of freedom at the slave nodes to be patterned after the displacement of those d.o.fs of the master node.

One of the limitations of the master-slave feature is that those degrees of freedom can be defined in the global directions only. Constraining a displacement or rotation along non-global direction is not available.

If you want to apply the constraints along directions which are inclined to the global directions, one way would be to define a dummy beam element connecting the two nodes along the inclination and assign a material having high E and zero density to that dummy member.

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!!!

Release Date: February 4, 2014

Installation Instructions:

RAM Concept V8i Release 5.1.1 can be installed side-by-side with previous release versions of Concept. There is no need to uninstall previous release versions.

Error Corrections in RAM Concept V8i Release 5.1.1

RAM Concept V8i Release 5.1.1 is a patch, containing error corrections and minor enhancements. Each issue addressed is summarized below.

Audit Design Section

When the user attempted to audit a cross section generated by a design section, an error with the message “Program Error (Report Parsing Error: bad master node contents)” resulted.

Large Calc Log

RAM Concept became unresponsive when the calc log had a large amount of output.

DXF Import

The import of a dxf file with missing xrefs into RAM Concept caused a program crash in specific and rare instances.

ASCE 7-10 Wind Import

When working with lateral loads that were imported from RAM Structural System, RAM Concept always treated wind loads as service loads, even when they might be ultimate level loads.

New Features in RAM Concept V8i Release 5.1

In addition to minor error corrections and enhancements, RAM Concept V8i Release 5.1 has two new features which are discussed below.

Auditor Tool Enhancements

This release includes an enhancement to the auditing tool, where results are now shown in a graphical format rather than in a text file. Results are organized in an intelligent tree structure and details can be drilled into as far as needed.

Utilization of 64-bit Memory Space

A 64-bit version of the program is now available. This removes memory limitations that may have otherwise occurred for exceptionally large and complex models, as well as computationally demanding features such as load-history calculations and vibration analysis.

New Features in RAM Concept V8i Release 5.0

In addition to numerous minor error corrections and enhancements, RAM Concept V8i Release 5.0 has a number of new features. Refer to the RAM Concept V8i Release 5.0 Quick Start Guide for additional information about the new features.

Vibration Analysis

The ability to perform vibration analysis has been added to RAM Concept, including the ability to solve for natural vibration frequencies and mode shapes and to perform dynamic modal superposition analysis to solve for RMS velocities, RMS accelerations, and response factors for footfall induced loadings.

Plot Animations

The ability to animate slab and vibration plots has been added.

Improved Integration with RAM Structural System

The integration between RAM Concept and RAM Structural System has been improved.

• The ability to launch RAM Concept as a module of RAM Structural System has been added, with automatic syncing of data and integrated files.
• The geometry export from RAM Concept to RAM Structural System has been enhanced in order to improve consistency between generated meshes.

Structural Synchronizer (ISM) 3.0 Compatible

Structural Synchronizer 3.0 is now supported including more robust slab behavior data.

Generic Eurocode 2 and AS 3600-2009 Standards Added

The ability to create a customized Eurocode 2 National Annex by inputting Annex factors has been added. The AS 3600-2009 standard has also been added.

Display the Difference Between Plots

RAM Concept now has the ability to display the difference between two plots (slab contour, reaction, or strip plots). This is useful, for example, to look at differential deflections between two load history steps for long-term deflection criteria evaluation.

Other Enhancements

There are also a number of other enhancements that have been added to RAM Concept 5.0, including:

• The ability to add/delete nodes from polygon objects.
• Improvements/enhancements to CAD import and export.
• A left/right beam tool has been added.
• The ability to append items to the clipboard from multiple Concept layers has been added.
• View history controls have been added.

Pre-Concept V8i Release 5.1 File Compatibility Warning:

RAM Concept V8i Release 5.1 can read all previous file formats, but writes files in a format that cannot be read by previous versions.

The following Release Notes are provided as a reference by Bentley's Technical Support Group.

RAM Concept

Latest Major Version

• [[RAM Concept 5.1.0 Release Notes]]
• [[RAM Concept 5.1.1 Release Notes]]

Previous versions

• RAM Concept 3.1 Release Notes
• RAM Concept 3.1.1 Release Notes
• RAM Concept 3.2 Release Notes
• RAM Concept 3.3 Release Notes
• RAM Concept 3.4 Release Notes
• RAM Concept 4.0.1 Release Notes
• RAM Concept 4.1 Release Notes
• RAM Concept 4.1.1 Release Notes
• RAM Concept 4.1.2 Release Notes
• RAM Concept 4.1.3 Release Notes
• [[RAM Concept 5.0.1 Release Notes]]
• [[RAM Concept 5.0.2 Release Notes]]

See Also

Product TechNotes and FAQs

External Links

Structural Analysis and Design Products

Modeling and Designing Gusset Connection in Staad.Pro

Consider the goal post frame shown below comprising open formed columns and open formed beam section at the top and a diagonal angle brace:

All sections have been inserted with a beta angle of 0 degrees. For the angle this means that the orientation is, showing the column and brace only for the top left hand joint:

If the beta angle for the angle section was changed to 90 degrees the angle would be orientated as shown below:          

If the beta angle for the angle section was changed to 180 degrees the angle would be orientated as shown below:

If the beta angle for the angle section was changed to 270 degrees the angle would be orientated as shown below:   

The angles must be inserted with a beta angle of either 0, 90, 180 or 270 degrees in order for the connection to design in the RAM Connection module. If the beta angle is changed to something other than these values to orientate the angle in the 3D view then the connection will NOT design in RAM Connection. This is due to the default values used by RAM Connection for the orientation an angle, in a Gusset plate design, being 0, 90, 180 and 270 degrees.

If we analyze the model above with pinned base supports and a point load of 20KN applied at node 2 along with a uniformly distributed load applied to the top beam of 10KN/m, as shown on the figure below:

Following this we can then select the RAM Connection module. In here we can select the members forming the gusset plate connection as shown below:

We can then select the Gusset plate icon to select the options for designing this type of connection. In this example, I have selected the AISC 360-05 (ASD) design code and the CBB_DA connection type (Column, Beam, Brace, DA signifies that the connection is a bolted connection):

If we then select OK we obtain, note the comment about the angle being considered as a brace, that is to say capable of accomodating axial load only, regardless of the fixity at the ends:

If we Close this dialog box we have the following and the connection can be selected using the Select Joints cursor or by double clicking on the RAM Connection Input selection:

This opens up the Connection Pad dialog box where the connection can be reviewed and edited if required. Note in the connection graphic the orientation of the angle has been changed to accommodate a connection to the gusset plate.

If we now go back to the Modeling tab and change the beta angle to 45 degrees say to orientate the angle as shown below:

And, if we now reanalyze the model and again go to the RAM Connection to select the members to design the connection:

This time we obtain:

In Summary:

• • • For single angles, only beta angles of 0, 90, 180 and 270 are acceptable for connection design in the RAM Connection module.
    • Gusset plate design is only applicable for design code AISC 360
    • If a brace is assigned in Modeling as a fixed ended member it will be considered as axial loaded only in RAM Connection. Braces must be defined with the Truss command in  Modeling if the connection is to be designed in RAM Connection module.

Note:  Version 14.06.01 is now available for download. Instructions for downloading installation files can be found here:

Accessing SELECT Services Online

RAM Frame In-Core Direct Solver

Problem:  Analysis time with the In-Core Direct Solver (selected in RAM Frame - Criteria - General, see figure below) is significantly slower in v14.06 than in earlier versions.

Work Around:  Analyze using the In-Core Direct Sparse Solver.

Resolution:  This issue was resolved in v14.06.01.

RAM Concrete Shear Wall Performance

Problem:  In the 64-bit version, models take a significant amount of time to load into the module. Other operations, like assigning wall groups and running the designs, are significantly slower.

Work Around:  Install the 32-bit version. Note that this can affect integration with RAM Concept. See following web page:

RAM Concept-RAM SS Integration

Resolution:  This issue was resolved in v14.06.01.

Fixed Braces and Calculated Reactions and Story Shears

Problem:  If braces are not pinned, the moment and shears in the brace member is not accounted for in the calculated reactions, frame story shears, and building story shears.

Work Around: None.

Resolution:  This issue was resolved in v14.06.01.

Column and Footing DXF

Problems:  When changing the Color/Layer options in the Footing Schedule tab, a crash occurs. When attempting to create the dxf, an “Error Opening Master Table” error appears:

After clicking Ok and trying to generate the DXF again, a series of “Key Already Present…” errors similar to the one below appears:

After clicking OK to bypass these errors and generate the DXF again, no file is created.

Work Around:  None

Resolution:  This issue was resolved in v14.06.01.

CAN/CSA S16-09 Minimum Composite

Problem:  The S16-09 Specification permits a percent composite as low as 40% when using composite action for the strength requirements, but the program was using a minimum of 50%.

Work Around:  None.

Resolution:  This issue was resolved in v14.06.01.

CAN/CSA S16-09 Modular Ratio, n_s

Problem:  In the calculation of shrinkage deflection the modular ratio n_t is used in S16-01 but the modular ratio n_s is used in S16-09. These values are quite different. The program allows for the user to specify n_t in Criteria – Canada Parameters in the RAM Manager but there is nowhere to specify n_s. The program, without indicating so in the user interface, is using the value specified for n_t for n_s when designing per S16-09.

Work Around:  When designing per S16-09, input the correct value of n_s where n_t is input. Note that S16-09 doesn’t use n_t, so there is no conflict with inputting the one value for the other.

Resolution:  This issue has been resolved in v14.06.01. The program will internally calculate n_s, it will not need to be specified by the user.

Defaults Utility setting for Snow vs. Roof Live load reversed

Problem:  If the option "Consider Snow Loads, Ignore Roof Live Loads" is selected in the default utility, then roof live loads are incorrectly considered and snow loads are ignored in new models. If the option "Consider Roof Live Loads, Ignore Snow Loads" is selected in the default utility, then snow are considered and roof live loads are ignored in new models. In other words, the setting works in reverse.

The selected setting for each model under Criteria - Member Loads works correctly, it is only the default setting for new models that is reversed. 

Resolution:  This issue was resolved in v14.06.01.

ISM - Update Repository Does Not Add New Items

Problem:  When updating an ISM repository from RAM SS, members or properties that were added to the RAM SS file are not added to the repository. This includes new beams, braces or composite beam stud zones to name a few.

Work Around:  This issue was resolved in v14.06.01.

When I try to create a new file, I get an error regarding tables.

Problem: When I try to create a new file, I get the following error:

"The specified Default Castellated Smartbeam Table (ramuk) could not be found, and neither was the table corresponding to the current setting from RAM Defaults (ramuk)."

Solution:

• Go to tools - Ram Defaults Utility (click OK if you get a message)
• Scroll down to Steel Beam defaults
• Double Click Steel Beam Tables options
• Make sure you have a valid selection, then click next and next until done with the tables part.

Note, with version 14.06.00.00 tables now get saved with the file which is a new thing. If you try to convert a model from an older version and the custom tables used with the original file are not present on the PC converting the file you can get similar error.

When I convert a v14.05 file with embedded Concept files, all design strips are missing.

Problem:  Embedded RAM Concept files are deleted during file conversion when v14.05 are opened in RAM Concept for both 32-bit and 64-bit versions. This removes all design strips and any other modified data, like changes made to slab areas or beams, that were saved with the file.

Work Around:   

1. Open the file in v14.06 and convert the file to the new version format.

2. Open Windows Explorer and find the .zip file with "Orig v14.5" at the end of the file name that is automatically created during the conversion process. Double click on the file. Find the embedded .cpt files. The file name will be same as ram model with .cpt###E at the end. Copy the files to the clipboard.

3. In Windows Explorer, navigate to the working directory (C:\Program Data\Bentley\Engineering\RAM Structural
System\Data\Working). Paste the embedded .cpt files from the v14.5 backup into this folder.

4. Launch RAM Concept from RAM Manager.

Resolution:  This issue was resolved in v14.06.01.

See Also

[[SELECTsupport TechNotes and FAQs]]

What is the Working directory?

A RAM Structural System model file (e.g. filename.rss) is literally a WinZip 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).

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.

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] . 

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 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.

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 with a db.sdf extension already exists.

This problem is caused by a problem with Microsoft SQL Server 2005 Compact Edition, a component installed with RAM Structural System. To fix it, select Control Panel from the Windows Start menu, and open Add or Remove Programs (for Windows XP users) or Programs and Features (for Windows Vista users). Then locate Microsoft SQL Server 2005 Compact Edition, and attempt to repair it. Windows XP users can do this by clicking the Change button and choosing the Repair option. Windows Vista users can do this by right-clicking on the listing and choosing Repair from the contextual menu.

If repairing the component fails, download an installer for SQL Server 2005 Compact Edition from Microsoft's website and install it. It can be found at:
http://www.microsoft.com/downloads/details.aspx?FamilyId=85E0C3CE-3FA1-453A-8CE9-AF6CA20946C3&displaylang=en

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?

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

RAM Defaults Guide [TN]

RAM Table Editing [FAQ]

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!

***NOTE: Version 14.04.00.00 of RAM Structural System included changes that resulted in a significant reduction in the incidences of the polygon intersection error***

The release notes for this version can be found here:

Version 14.04.00 Release Notes,

Error in Polygon Intersection

The message, “Error in polygon intersection” is fairly general, and could be indicative of several different conditions related to the geometry of a RAM SS model. Several polygons exist on any floor plan such as:

• surface loads
• snow loads
• areas of deck

The program also defines some internal polygons when calculating tributary areas of individual members. We call these

• “beam loops”

A polygon error may occur at various stages of the modeling and design, specifically during any of the following events: 

• data check in the Modeler 
• building of the “Framing Tables” at the start of any design module 
• building the “Frame Data” in RAM Frame 
• analyzing Wind loads in RAM Frame.

Modeler - Data Check

When a polygon error occurs while running the data check, the modeler will terminate. This should not cause you to lose any recent changes, however.

One possible cause for such an error is the presence of zero-length beams or walls in the model. These members cannot be seen, but the numbers can be displayed. If you see beam numbers with no associated beams or overlapping beam numbers, this will help in locating the problem. You can then delete these beams with a fence. The beam numbers should then disappear as confirmation.

Under normal circumstances, zero-length beams cannot be modeled, but they can be imported from DXF or Revit, or they can sometimes result from modifications to the grids after the beams have been modeled.

Beam or Column Design - Framing Tables

When any design module is initiated, the program starts by “Building the Framing Tables”. During the process, the program goes through the beam loops one at a time to determine the tributary loads. If a polygon error occurs while the framing tables are being built, the user can identify the beam number and coordinates together with the floor type where the program stopped processing information. This information can be helpful in locating the source of the error.

The polygon error may be followed by a second error message saying, “SetLineEq() passed two identical points at 0.00 0.00”.

This usually indicates a problem with the shape of the beam loop. For example, if there is only one beam connected to an interior column within the deck area, a polygon error will arise for one of the members in that immediate vicinity:

A second type of message saying, “Clipping a degenerate polygon” or “Too many intersection points” indicates a different type of polygon error.

The error in this case may be due to internal numerical accuracy, especially when the beams or polygons in that area are ever so slightly skewed in plan.

This type of error is often caused from having multiple, overlapping surface loads or decks. The program only counts the top-most layer of surface loads when analyzing a structure, but it must make a determination about what load is "on top" by comparing the areas of the various overlapping surface load polygons as they were applied. When multiple layers of loading are used, this calculation becomes more complex.

The program may give an error when only a tiny sliver of one load overlaps another, or if the edge of a surface load polygon is very slightly off of a beam line. In this case, it is necessary to delete and re-apply that surface load in a different area. The more complicated the beam loops, the more likely a polygon error will occur.

In the example below, the end coordinates of beam 113 did not match the end of beam 108 or the column in that location creating a tiny polygon for the program to deal with. Furthermore, the surface load also angles just slightly away from beam 98.

To solve the problem in this case, beam 113 was adjusted to match the column coordinates and the surface loads were recreated.

Tip: It may be necessary to save the file under a test name and systematically eliminate load and deck polygons from the file until it works, then return to the original file and rework the problem area only. When laying out deck or surface load polygons, first turn off all the unnecessary snap points. Typically the only snap point needed are Columns, Beam Ends, and Wall Ends:

RAM Frame – Building Frame Data

After the framing tables are finished, the RAM Frame program goes through a second step of constructing the Frame Data. During this phase the program determines the diaphragm masses and the gravity for notional loads of each diaphragm. This process is similar to the load calculations done during the framing tables, but slightly more complicated because the program is working with the larger polygon defined by the entire slab edge.

Regretfully, the error in RAM Frame does not isolate the level type with the problem. In order to isolate the problem area the user should systematically remove stories from the story data until it works, then go back and examine the loads or decks on the problem level.

RAM Frame – Analysis / Wind Exposure data

If a polygon error occur near the end of the analysis in RAM Frame the issue is a little different. At this point the program is creating the polygons associated with the wind exposure. These shapes determine the total wind load tributary to any diaphragm and can be reported using Reports – Exposure boundaries.

Typically the situation that causes this error is a complex slab edge that overlaps itself. Consider the geometry pictured below. If the inlet is 1’ wide and the program will function perfectly well when the slab edge overhang is less than 6” on each side, but once the overhangs are increased such that they meet or overlap problems can occur:

RAM Concrete – Meshing Diaphragm

Below is a polygon intersection that was produced when the diaphragms are meshed during the RAM Concrete Analysis. This error is most likely associated with too many overlapping deck polygons. The problem floor level will be identified in the Analysis Status window. The coordinates, defined in inches, can be used to find the offending polygon.

See Also

RAM SS Common Framing Table Errors [TN]

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!

Framing Tables Errors

General

There are many instances where modeling errors in Ram Structural System are not caught by a Data Check in Ram Modeler. Data Check looks at general geometric information, but it does not attempt to validate all of the information needed to compile the Ram Gravity Framing Tables.

Many of these errors are slab edge or slab opening related.  When one way decking is modeled, slab edges and slab openings must be associated with adjacent beams/walls.  For this reason, avoid using free formed slab edges/openings with one way decking.  Instead, use Layout - Slab - Slab Edge - Whole Perimeter and Layout - Slab - Slab Opening - In Bay to model the slab edges and slab openings.  Then, revise the slab edges/openings where the offset changes.  To further ensure accuracy, only use beams and walls in your Options - Set Snap Points.  Finally, use a positive, non-zero, slab edge offset.  Zero inch slab edge offsets are permitted, but the program algorithms were originally developed assuming non-zero offsets and some configurations can be problematic.

Below are several common modeling configurations that cause problems for the program but are not caught by Data Check.  The right hand image shows the typical error message produced while building the framing tables.  In the background, the framing tables usually halt at a particular member on a particular floor as shown in the left hand image.  Typically, but not always, the modeling issue occurs in the vicinity of the member where the framing tables halt. 

Illegal Framing Configuration

Most illegal configuration errors are slab edge or slab opening related.  Subtle inaccuracies in member end locations can cause small slab edge segments that are problematic for the framing tables.  Review the member end coordinates using the Layout - Beam - Show command and the slab edge coordinates using Layout - Slab Edge - Show.  Try remodeling the slab edge using the whole perimeter command. 

Missing Slab Edge

Many missing slab edge errors are related to having portions of the structure isolated from the perimeter beam loop under one way decking as shown below.  To resolve the issue, model two beams that connect the isolated structure back to the adjacent framing.  If these beams are modeled parallel to the deck span, they will take no tributary load from decking.

Internal Error in AdvanceNodeList()

Typically, these errors are similar to the missing slab edge error.  The main difference is that there usually is only a single beam/wall connecting the interior structure to the perimeter beam loop as shown below.  Modeling a second beam will resolve the issue.

Beam Loop Intersection not Found

Typically, beam loop intersection errors are related to line loads that are slightly askew from a beam.  Often discrepancies arise when a single line load is added over multiple beams that are not truly collinear.  Review the coordinates of the beam and line load using the Layout - Beam - Show and Layout - Load - Line Load - Show command.  To resolve the issue, delete the line load(s) and remodel them using the Add On Beam command.

This error can also be associated with changes in one way deck orientation or properties.  One way decking should always transition along a beam/wall.  That includes transitions from one way decking to two way decking. 

Furthermore, one way deck angles are normally limited to angles between 0 and 179.99 degrees. If imported models have deck angles larger than 180 degrees, this can also cause a beam loop error.

Failed to Find Slab Edge Loads

These errors are usually related to tolerance problems between the slab edge loop and perimeter beam loop.  Review the slab edge and beam coordinates using the Layout - Slab - Slab Edge - Show and Layout - Beam - Show command.  Try remodeling the slab edge using the whole perimeter command.

Failed to Create Slab Edge Load Polygons

This error tends to happen when there is a small level with an incomplete perimeter of framing similar to the one pictured below. Adding the short beam on Gird B between the two concrete columns completes the loop with beams 40, 39 and 41. Adding the other beams would only be required if the deck was intended to load beam 42.

Missing or Incorrect Loads on Perimeter beams

Since the advent of free form slab edges, there have been a few framing slab edge configurations that can lead to unexpected loading on the perimeter beams.

In the image below, the slab edge is slightly skewed to the perimeter beam, and crosses it at one point. Consequently beam 8 may be assumed outside of the slab edge and will not receive loads from the one-way deck.

The best way to avoid the problem when using one way decks is to align the slab edge with the perimeter beams and use at least a 1" outboard overhang. Furthermore, make sure the perimeter framing creates a closed loop around the diaphragm. Small gaps in the perimeter framing can also cause problems.

Forcing a "Reframe"

In some cases the beam design module can open and not require a rebuilding of the framing tables, what is commonly referred to as a reframe. A reframe is generally triggered by making any kind of change on a particular level. You can also force a reframe by changing any of the Ram Manager criteria like Self Weight or Live Load Reduction code.

If the design module produces an unexpected error, one simple thing to try is forcing a reframe. You can change one the criteria mentioned above, and click OK. You should get a window like this if previous results are going to be discarded:

Then change the criteria back the way it should be and try the beam design again.

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!

This page contains a list of new OpenSTAAD functions which have not been documented yet.

• Load Functions

The following OpenSTAAD function extracts the number of loads (Primary and combination load case) and corresponding combination factors for a combination load case.

Load.GetNoOfLoadAndFactorPairsForCombination varLoadCombNo

Where:

varLoadCombNo

A long variable which stores the number of load cases present in the combination load case.

VB Example

Dim lcase As Long

GetLoadCaseinCombination = objOpenSTAAD.Load.GetNoOfLoadAndFactorPairsForCombination(lcase)

This page contains a list of new Load functions.