STAAD.Pro Model

Relevant STAAD.Pro model (.std file) can be downloaded from the following link:

STAAD.Pro model for IS 800:2007 verification example

Critical Design Forces

For Sectional Properties and Critical design forces, go through the following post:

Section Classification of Laterally unsupported ISMB section

Moment Capacity Check 

STAAD.Pro Design Output

1. Why does the program give some strange numbers when the joints are generated graphically by e.g. copying. We enter a number that has no decimals (7.00m) and in the input file the coordinate is 7.0001.
2. When I use the Node Dimensioning Tool (Tools | Display Node to Node Dimension), how can I turn off just one dimension line rather than all of them with the Remove Node Dimension option?
3. I am trying to model a beam connecting to the flange of a column instead of at the center. How is this modeled?
4. How to model Pile cap attached to batter and vertical piles in STAAD.Pro?
5. In the new 3D rendered window, how can I view the structure in plan, elevation and isometric view like I can with the other windows? Also, how do I pan across the model?
6. When I save a file from the STAAD.Pro GUI, the joint coordinate data and member incidence data are written into the .std file in such a manner that there are several entries per line, separated by semi-colons. I would like it to be written in a way that the joint coordinate data is written as one joint per line and the member incidence data is written as one member per line. Is there some setting in the program to facilitate this?
7. Can you please tell me how to transfer data from EXCEL to STAAD-PRO?
8. How do I graphically display the distance between two nodes?
9. I have a rather large frame building consisting of several floors. I want to look at individual floors by themselves without the rest of the structure cluttering up the view. Can you tell me how to do that?
10. How do I access online help in STAAD.Pro? The F1 key does not bring up any help screens.
11. How can I convert single line input to multiple line input? The program currently converts my joint coordinate and member incidence data from multiple line to single line input.
12. How do I merge 2 staad models?
13. After analysis , I get the following warning in the output file :
    **ERROR** PLATE NO. 2448(JOINTS 2017 - 2088 - 2160 - 2089) IS BADLY SHAPED, WARPED, NOT CONVEX, OR NOT NUMBERED COUNTER-CLOCKWISE.
14. How do the nuclear users review staad.pro error report

1. Why does the program give some strange numbers when the joints are generated graphically by e.g. copying. We enter a number that has no decimals (7.00m) and in the input file the coordinate is 7.0001.

In STAAD.Pro, there is a concept called a Base Unit system. There are 2 options under this : The English or Imperial units (Foot Pound, etc.) and Metric units (meter, kg, etc.)

The base unit is set at the time of installation of the program. Once it is set, you can see what the setting is, as well as change it, by starting the program, going to the File menu, choosing Configure, and then choosing Base Unit.

If your base unit setting happens to be inconsistent with the units in which you create the model, that will cause the type of problem you mention. For example, if the base unit system is English, and you create the model using Meter and Kg unit, it will cause numbers to be not rounded.

You can rectify it by setting the base unit to be consistent with your working units through the File-Configure option we just described above.

2. When I use the Node Dimensioning Tool (Tools | Display Node to Node Dimension), how can I turn off just one dimension line rather than all of them with the Remove Node Dimension option?

 You can use the Node to Node Dimension and re-dimension an exisiting dimension line. This will remove only the dimension line that has been re-dimensioned.

3. I am trying to model a beam connecting to the flange of a column instead of at the center. How is this modeled?

 You have to use a facility called member offsets. You "offset" the face of the beam by a distance equal to half the depth of the column cross-section. An example of this can be found in Example # 7 in the STAADPro Examples Manual. 

4. How to model Pile cap attached to batter and vertical piles in STAAD.Pro?

1) The pile cap can be modelled using either plate elements or solid elements. If the thickness of the cap is comparable to its plan dimensions, a solid element model is preferable. If the plan dimensions are much larger than its thickess, plate elements should be a better choice. One drawback of using solid elements is that, by their very nature, they lack rotational degrees of freedom. Consequently, for a monolithic structure such as a concrete pile cap with concrete piles, the rigid connection between piles and the pile cap cannot be properly accounted for, if the cap is modelled using solids.

2) The piles themselves can be modelled using frame members. The supports for the pile come in 2 varieties - skin friction and end bearing. Skin friction action can be accounted for by modelling each pile as several collinear members and specifying a support at each of those common nodes. End bearing action can be modelled using fixed or pinned supports. The support spring stiffness is obtained by multiplying the soil subgrade reaction by the influence area of the associated support node. A standard text book on pile analysis should be a great source of information on obtaining the spring constant of the supports.

5. In the new 3D rendered window, how can I view the structure in plan, elevation and isometric view like I can with the other windows? Also, how do I pan across the model?

 You can perform rotation and other viewing functions by right-clicking your mouse button and choosing the appropriate viewing tools. Also, you can use the viewing icons in the main toolbar for viewing the model in plan, elevation, isometric, etc. and also to pan and zoom in/out.

6. When I save a file from the STAAD.Pro GUI, the joint coordinate data and member incidence data are written into the .std file in such a manner that there are several entries per line, separated by semi-colons. I would like it to be written in a way that the joint coordinate data is written as one joint per line and the member incidence data is written as one member per line. Is there some setting in the program to facilitate this?

Close all input files.

From the File menu, select Configure - Input File Format. Switch on the items for which you wish to have the single line format. Click on Accept.

Then, choose File - Open - open the input file. Click on Save. This setting will ensure that all desired data will henceforth be saved in the single line format.

7. Can you please tell me how to transfer data from EXCEL to STAAD-PRO?

The only data which can presently be transferred from Excel to STAAD is the geometry information, namely, joint coordinates, member incidences, plate element incidences, and solid element incidences. To do this, first select the cells in Excel where you have the numbers, and choose Copy from Excel's edit menu.

Next, come into the STAAD program. The data may be brought into a new STAAD file or an existing STAAD file. Accordingly, open a new file or an existing file.

Select the Geometry page from the left side of the screen, and choose the Beam, Plate or Solid sub-page depending upon the type of information you wish to bring in.

If you are looking to bring it into a New file, close the Snap/Node dialog box which is open on the right hand side of the screen.

For copying the joint coordinate data, click on the appropriate starting cell in the Node Tables grid on the right side, and type Ctrl+V or select paste from the Edit menu.

For beam incidence, plate incidence or solid incidence data, click on the appropriate starting cell in the Beam Tables, Plate Tables or Solid Tables grids on the right side, and type Ctrl+V or select paste from the Edit menu. You should see the numbers you copied from Excel appear in those cells.

8. How do I graphically display the distance between two nodes?

 Go to Tools | Display Node to Node Dimension or click the dimension icon. If you have kept the original toolbar layout, the icon is in the first row, 3rd group from the left, and it looks like a double arrow with 2 parallel verticle lines on either side.

9. I have a rather large frame building consisting of several floors. I want to look at individual floors by themselves without the rest of the structure cluttering up the view. Can you tell me how to do that?

Method 1 :

a) Orient the view of your model in such a way as to make it convenient to extract using a mouse, the portion you want to view separately. This can be done from View | Orientation, or by clicking on the icons available for this.

b) From the select menu, select the Geometry cursor. Then, using your mouse, create a window around the region you wish to view. That region will be highlighted.

c) Click the right mouse button and select New View. Or, from the View menu, select New View. Set the button on "Create a new window for the View", and click on OK.

The region will now be displayed in a separate window. Once in this window, you can change the viewing angles using View | Orientation, or through the orientation icons, or simply by pressing the up, down, left or right arrow keys on the keyboard.

Method 2 :

This method involves cutting a section using the Tools - Cut section option. Details are available in Section 2.3.4 of the STAAD.Pro Graphical Environment Manual, which can be accessed from Help - Contents.

10. How do I access online help in STAAD.Pro? The F1 key does not bring up any help screens.

The F1 key for help is currently not operational in STAAD. We are working on implementing this for one of the forthcoming releases.

To obtain online help in STAAD, you can do one of the following:

From the Help
menu, if you click on Contents, if will bring up all the STAAD manuals. You can search for specific information, or go through the topic list to select the items you want.

From Help, if you click on Multi Media help, it will bring up a set of movies which will explain the procedure for creating a
model.

If you click on the Start button on your Windows desktop, select Programs, choose STAAD.Pro 2001 followed by STAAD.Pro Online
Documentation, it will bring up the same set of information as the one you can access from step (1) above.

11. How can I convert single line input to multiple line input? The program currently converts my joint coordinate and member incidence data from multiple line to single line input.

 Start STAAD.Pro. Select File - Configure.

Click on the tab called Input File Format

If you want Single line format, switch on the check boxes. If you want Multiple line format, keep them "unchecked".

Click on Accept.

Then from the File menu, open your STAAD input file. When you Save the file from the Graphical screen, the data will be saved in the format you chose in the step above.

12. How do I merge 2 staad models?

Start STAAD.Pro. Open the first file. Keep it open.

STAAD another instance of STAAD.Pro. Open the second file. Stay in this file.

Go to the Select menu, and Select All Geometry. From the Edit menu, select Copy.

Go back to the screen of the first file. From the Edit menu, select Paste.

You will be prompted to specify the X, Y and Z distances by which to move the structure of the second file before it gets copied to the first structure. Specify those values and click on OK.

13. After analysis , I get the following warning in the output file :

**ERROR** PLATE NO. 2448(JOINTS 2017 - 2088 - 2160 - 2089)

IS BADLY SHAPED, WARPED, NOT CONVEX, OR NOT NUMBERED COUNTER-CLOCKWISE.

 Plate element should me be modeled using some rules. A plate element’s aspect ratio should be as near to 1:1 as possible. Aspect ratio is defined as the ratio of the length of the shortest side to the longest side of the element. Aspect ratios in excess of 1:4 should be avoided. When assigning nodes to an element in the input data, the nodes must be specified either in clockwise or  counterclockwise order around the perimeter of the element. Kindly find the link to the document which explains the rules for proper modeling of plate elements.

http://communities.bentley.com/products/structural/structural_analysis___design/m/structural_analysis_and_design_gallery/257477.aspx

[[Developing the model]]

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

External Link

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!

What is the difference between the Pdelta and a Nonlinear Analysis ? I tried both on my structure and did not observe any significant difference.

In a Pdelta analysis you are accounting for the second order effects resulting from displacements ( normally Large delta and Small delta ). However if the structure or loading is such that the analysis results in large displacements, then in addition to accounting for the effect of these secondary forces, one should also account for the fact that the stiffness of the structure may change significantly as it deflects. Nonlinear analysis allows you to account for such changes in stiffness with application of load. Depending on the nature of the problem, the loads should be applied in steps while the stiffness is adjusted multiple times within a load step to arrive at a converged solution.

In your structure, nonlinear effects may not be that significant and hence you may not have noted a significant difference between a second order and a nonlinear analysis. If the strucrure stiffness would have changed significantly, you would have seen the effect in results.       

FAQ1:

Two members have been assigned the same section HE800B and the loading on the member applied are also similar, which is compression and bending. However, one of the members have been classified as CLASS 1 and the other has been classified as CLASS 4. Why?

Answer:

The section-classification of sections as per EN 1993-1-1:2005, Table 5.2, for bending and compression of both the Internal Compression Parts and Outstand Flanges depends on the values of α and Ψ, which in turn are used to determine the c/t ratio. These parameters are dependent on the intensity of the loads and thus the section classification cannot be expected to be the same even if the sections are same and similar loading has been applied on the members. The intensity of loading also plays a prominent role.

I am getting a WARNING: IN UNIFORM MEMBER LOAD. ITEM "f3" NOT PROVIDED FOR MEMBER     2 CASE    1

             "f3" ASSUMED TO BE MEMBER LENGTH =   12.00 . What does the warning mean ?

When one specifies uniform member load on a member the software expects the data to be according to the following format

MEMBER LOAD

Member_list UNI GY –

MEMBER LOAD

member-list { { UNI | UMOM } dir-spec f₁ f₂ f₃ f₄

where f1=magnitude of load

f2 =distance of start of load from start node of member

f3=distance of end of load from start node of member

f4=perpendicular distance from shear center to plane of loading

when f2 and f3 are omitted, then the member load is applied for the full length of the member. However if f2 is provided but f3 is not provided, then a warning message like the one mentioned appears in the analysis output file. In such cases the software assumes a value of f3 to be the full length of the member and the loading is applied accordingly. So if the entire length of the member needs to be loaded simply specify f1 and leave out both f2 and f3. Else if the member is partially loaded, one may use both f2 and f3.

After installing Staad .Pro, the following error comes  : " The application has failed to start because xmllite.dll not found. Re-installing the application may fix this problem. “

How to resolve this?

Download the xmllite.dll file from the following link :

 http://communities.bentley.com/products/structural/structural_analysis___design/m/structural_analysis_and_design_gallery/254797.aspx

 Extract the .dll file  and save this file in C:\WINDOWS\System32 folder. If there is already a file by the same name, it would ask you to replace the same. You need to replace it. This will solve the problem.

Error or Warning Message

I tried to install Staad Foundation Advanced with stfad0700*****.exe. I can't open the software and it prompts "C:\Staad Foundation Advanced 7\XMlLite.dll iseither not designed to run on Windows or it contains an error. Try installing the program again using the original installation media or contact your system administrator or the software vendor for support." I tried to reinstall the program but it still did not work properly and prompted the same.

Solution

Search for xmllite.dll file in your local computer; most likely you will find it in \System32 folder. Go to STAAD.Foundation Advanced folder and rename or delete the XMllite.dll file. Run the program, it should work fine.

Question: In our STAAD the deflection value in the member query box shows that“Seismic load involved dynamic analysis, displacement results will not be available”. Kindly please inform how to apply the limiting displacement value in STAAD for RCC members.

Answer: You are trying to get the local deflection values of a beam using a member query facility from a Response Spectrum load case. The very basic theory of the Response Spectrum analysis is that a static analysis is performed for each mode considered on dynamically displaced modes. The structural responses obtained from each mode are combined using a modal combination like SRSS, CQC etc. The sign of the responses are lost in the modal combination. Relative nodal displacement obtained from a Response Spectrum load case is meaningless. The reason is that in response spectrum analysis the joint displacements represents the maximum magnitude of the response quantity that is likely to occur during seismic loading. Any response quantity like relative nodal displacement should be calculated from actual displacements of the dominant mode considered during analysis.

We can find out the dominate mode from the “Participation Factors” table provided in theoutput report as shown below.

It can be see that 1st mode is contributing 81.04 % mass participation and 2nd mode iscontributing 80.39 % mass participation. We can conclude that 1st Mode is the dominant modeof vibration for X directional Response Spectrum load case and the responses obtained fromthe modal analysis for this 1st mode would govern the responses for X directional ResponseSpectrum load case. Similarly, we can conclude that 2nd mode would dominate the responsesobtained from Z directional Response Spectrum load case.

In order to check the local deflection of a beam we can think of checking it from the individualload case created for dominant mode rather than using the actual Response Spectrum loadcase. As discussed earlier, the results obtained from a Response Spectrum load case arealways unsigned and a quantity like relative nodal displacement computed from unsignedabsolute maximum nodal displacement would be a vague quantity which has no meaning inreal sense.

STAAD.Pro can be used in this purpose to get the responses of an individual modal load case. The program has been equipped with this facility. You can tell the program to generate individual modal load cases. The program generates individual modal load cases as primary load cases with the load case numbers defined by the users. You have used Response Spectrum load cases like the following:

LOAD 16 LOADTYPE Seismic TITLE SEISMIC + X

------------------------------------

-----------------------------------

SPECTRUM CSM 1893 X 0.105248 ACC SCALE 1 DAMP 0.05

SOIL TYPE 3

You can change the commands in the following manner.

LOAD 16 LOADTYPE Seismic TITLE SEISMIC + X

------------------------------------

-----------------------------------

SPECTRUM CSM 1893 X 0.105248 ACC SCALE 1 DAMP 0.05 IMR 1 STARTCASE 200

SOIL TYPE 3

Graphically, it would look in the following manner.

On doing this, you are instructing the program to generate individual modal load case for 1st mode which will be the dominant mode for the X direction. This load case will have load case number as 200.

You can choose this load case to check local beam deflection checking purpose. Please refer to the attached picture.

Use of Two way decks in RAM Structural System

The table below clarifies how One way and Two way decks can be used in RAM SS v14.00 or later:

1. One way deck always requires a complete nodal network, a network of supported beams or walls such that a tributary for every member is defined and encompasses the entire one way deck area.
2. If you have a semi-rigid diaphragm with a one way deck that is not properly supported by a network of beams, RAM Frame or RAM Concrete may run without warning, but loads will be zero.
3. When Two way deck is used, only two modules can give results. RAM Frame with a semi rigid diaphragm option (2-way rigid diaphragms are also allowed starting in v14.03 and were altered in 14.07 see Criteria - Diaphragms for details), or RAM Concrete. Furthermore, the user must specify the deck effective E value, thickness and Poisson's ratio for those modules to work. The diaphragm will always be meshed, and out-of-plane stiffness will always be assumed. Hence the beams (if there are any) will resist less force compared to a one way system. Any such beams have a centroid alignment to the center of the slab.
4. No automatic Live Load reduction calculation is performed for members carrying loads from two-way slabs. The reduction to be applied to the Live Load on such members must be assigned to the member in the Modeler (e.g. Layout - Columns - LL Reduction). 
5. RAM Concrete typically considers skip loading for live loads on the beam lines lying under one way decking, if desired. A beam line lying under a two way deck can have skip loading cases only if line and point live loads are applied directly on it. Currently, the surface loading applied to two way decks does not generate any skip loading cases.

Other notable warnings:
RAM Frame, using a Two way deck without using a semi-rigid diaphragm (only applies to versions 14.00 to 14.02):

RAM Frame: Two-way Deck Found Inside Diaphragm 1 of Story 2.  The Diaphragm Type is not Semirigid.  Gravity Loads on the Diaphragm Disregarded for the Analysis.  Do you want to continue?

RAM Steel - using Two way decks always gives an error of some sort, example:

Warning: Failed to Create Slab Edge Load Polygons for diaphragm 1 on Layout Type Roof. Slab edge loads will not be applied to any beams around the perimeter of that diaphragm. Disregard this warning if the slab edge is Two-way deck.

Hybrid Decks

For Hybrid Deck levels, those that include areas of both one way deck and two way deck, the rules for nodal networks still apply to the one-way decked area. If the network is not complete various framing tables errors can occur.

Furthermore, when the level is meshed in Ram Frame or Ram Concrete you will see that the mesh covers the entire floor so that the diaphragm is continuous. This can cause some unexpected behavior in the one-way regions. Specifically the meshed slab can help in resisting some of the applied loads, effectively holding up the beams.

There is an option in the Concrete Analysis mode, under Criteria - Analysis to alleviate this effect. 

By not checking the option to "Include Out-of-Plane Stiffness for One-Way Decks in Hybrid Slabs" you are telling the program to use a near zero stiffness element in the one-way deck areas so that the beams have to do the work.

For these reasons, mixing one and two way decks in the same diaphragm is not generally recommended.

Concrete Column design with Two-Way Slabs

In Ram Concrete, the column K factor is determined based on the relative stiffness of the beams to the columns. The stiffness of 2-way slabs is not considered in this calculation, so the user should manually assign the proper K factor for columns supporting 2-way slabs.

As noted above, Live Load reduction percentages also need to be manually assigned.

Semi-rigid Diaphragms for Two-Way Slabs

Out-of-plane stiffness is assumed not only for gravity loads, but also for lateral loads when the deck is two-way and semi-rigid only. When the diaphragm is set to rigid, out-of-plane stiffness is ignored in the lateral load cases. Prior to version 14.07, rigid diaphragm two-way decks considered the out-of-plane stiffness for all loads. Ignoring out-of-plane stiffness of rigid, two-way decks was a major change in version 14.07. Consequently, if you are using version 14.06 or earlier and are relying on slab out-of- plane stiffness to tie your columns together and provide frame action, you must change the diaphragm setting from rigid to semi-rigid to get similar behavior after updating to the new version. The change can produce instability errors, large deflections, and significantly different Lateral Self-Equilibrium forces when importing forces into RAM Concept in v14.07 compared to earlier versions.

There are some general concerns in RAM Frame for these diaphragms. The distribution of gravity loads is determined by meshing the diaphragm and then the program calculates the gravity load that is tributary to each node.  Gravity columns/walls are ignored in the Frame finite element analysis. If you have gravity columns and/or walls, the gravity forces on the lateral members will be inaccurate unless you utilize the consider gravity columns/walls as springs options. However, utilizing this option will have an impact on the lateral analysis as well. The following concepts apply to one way decks with out-of-plane stiffness considered, too.

Consider a five story shear wall building with two way 8 inch concrete slabs. Here is the typical plan.

The moments at the base of the walls for a lateral load case in the X direction are 13555 k-ft and the shears are 242 kips.

If you run the same load case and include the gravity columns as springs the moments drop to 11163 k-ft as the gravity column spring form couples that resist much of the overturning moment. The wall major axis shear forces stay the same. You would get similar results if you modeled all of the columns as pinned lateral columns.

As the out-of-plane stiffness of the diaphragm and axial stiffness of the columns increase the moments in the walls decrease. Conversely, when there is negligible out of plane stiffness to the diaphragm, the moments in the walls would not be affected. (Using version 14.07 or later with rigid two-way decks transforms this behavior so that the slab out-of-plane stiffness is only considered for gravity load cases. See Criteria - Diaphragms for details.)

In the RAM Concrete Shear Wall Module all of the design forces, including gravity load results, come from the RAM Frame analysis. For the design of shear walls it is important to understand the impact gravity columns have on the forces in the walls.

Transfer Forces

A column or wall may set directly upon a 2-way deck without the need for a beam on the story below (using version 14 or later). The force from the vertical member will transfer through the meshed slab to the supports below. Since this requires a finite element analysis of a meshed two way slab, it has the same limitations in the table above, i.e. it only works using Ram Frame or Ram Concrete analysis.

Generally we recommend that the columns or walls that offset should be modeled as lateral members so that the analysis in RAM Frame will consider those members in the analysis.  That way the program can display or report important information like axial member forces and nodal displacements.

We also recommend modeling a transfer beam in addition to the slab when reasonable to do so.

There are some special considerations when using RAM Structural System in conjunction with Ram Concept for transfer slabs. See these topics for further details:

• RAM Concept-RAM Structural System Integration TN
• Modeling Podium Slabs TN

See Also

RAM SS Analysis Types

RAM Frame - Criteria - Diaphragms

RAMSS Common Framing Table Errors

RAM SS Semirigid Diaphragms

Transfer Slabs

Structural Product TechNotes And FAQs

Query: Having problem while opening STAAD.Pro model

Answer: Right click on the model and choose the default program to open that as shown below:

You choose the following application as the default program to open that.

Overview

This page addresses common issues and questions specific to concrete beams designed and analyzed in the RAM Concrete Module of RAM Structural System

Slab Self-Weight

For rectangular beams, the portion of the slab that intersects the rectangular beam is included in both the slab self-weight and the beam self-weight. For T-shape beams, this double counting of self-weight does not occur. See RAMSS Gravity Loads [FAQ] for details.

Loading Diagrams (RAM Concrete Analysis - Reports - Beam Load Diagram)

The beam loading diagram displays point and line loads values that are calculated by the program and applied directly to the member by one-way decking or associated with beam self-weight.

The following information is excluded from the reports:

• Magnitudes of supported beam (or column) reactions: These are excluded because the loads are applied as line loads on the supported beams. Force transfer to the supporting beams is completed in the finite element analysis. The program does not analyze these beams separately with point loads as is done in RAM Steel Beam. The location of the supported reactions is shown in the report for convenience. The Load Diagram Report in RAM Steel Beam can be used to report the tributary point load distributed to the beam if one-way decks are used.
• Loads from transfer columns and walls above: Vertical reactions from levels above are collected by the program and applied as loads on levels below. Neither the magnitude or location of these loads are included in the Load Diagram Report.
• Load from two-way decks: For models containing beams and two-way decks, the surface loads are applied as a series of nodal loads at each finite element node. These loads are directed into the framing members and supports based on relative stiffness in the finite element analysis. The program does not perform a yield-line analysis and determine a trapezoidal line load on each beam member. Since a line load is not calculated and placed on a member, the floor load from the two-way deck will not be represented in the Loading Diagram Report. The Beam Load Diagram Report will show the beam self-weight only, since this is the only line load that is calculated by the program and applied directly to the beam.

Deep Beam Design

The ACI code classifies beams with a clear span to depth ratio greater than 4 as deep beams. RAM Concrete Beam can check if beams exceed this ratio. The option to include or exclude this check is found in RAM Concrete Beam – Criteria – Beam Design – Design Checks/Forces tab:

When the option is selected, a design warning is produced when the clear span to depth ratio exceeds the threshold. . RAM Concrete Beam does not design deep beams for flexure and shear;  It is the user’s responsibility to design deep beams outside the program.

ACI 318 also requires deep beam checks when a concentrated load is located within twice the member depth from the face of the support. RAM Concrete does not check the location of concentrated loads and will not generate a design warning for this situation.

Torsion Design

RAM Concrete Beam can check the torsion demand to the threshold torsion defined in ACI 318-08 11.5.1. The option to include or exclude this check is found in RAM Concrete Beam – Criteria – Beam Design – Design Checks/Forces tab:

When this option is considered, a design warning will be reported when the beam torsion exceeds the threshold torsion. RAM Concrete Beam does not design the torsion reinforcement;  It is the user’s responsibility to design this outside the program. The Beam Design Report will report the maximum factored torsion at each station and the f_T*T_c.

Effective Depth

The effective depth that is used in the beam design is based on an assumed cover assigned in RAM Concrete Beam – Criteria – Beam Design – Reinforcement tab.

The program does not automatically determine the effective depth based on the code minimum cover and the longitudinal and transverse bar sizes. If the assumed effective depth is greater than the actual effective depth calculated from the minimum cover and bar sizes, a design warning similar to the following will be displayed:

When this warning occurs, the assumed cover should be increased. This can be done globally for all beams (RAM Concrete Beam – Criteria – Beam Design – Reinforcement tab) or can be assigned beam by beam (RAM Concrete Beam – Assign – Reinforcement Layout).

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

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!

Global Analysis (clause 5.2)

The EN 1993-1-1:2005 has prescribed use of the first order analysis if the buckling factor of the structure is greater than 10 if elastic analysis is employed (equation 5.1, clause 5.2.1). This has been specifically meant to ease the work of the structural engineers using manual methods for analysis and design.

While analyzing the structure with a computer, a designer can employ the second order analysis without verifying the aforementioned condition to generate more accurate analysis results. If the effect of deformed geometry is not supposed to be substantial the additional second order forces would be negligible from the analysis results.

However, if the user wishes to do this check and then employ a first order or second order elastic analysis, he can initially specify a PERFORM BUCKLING ANALYSIS. If the reported Buckling factors are reported as being bigger than 10, he can employ the first order analysis by specifying PERFORM ANALYSIS – else he can resort to using the second order analysis by specifying a PDELTA 30 ANALYSIS. The PDELTA 30 ANALYSIS calculates both the big delta and small delta effects.

A complete analysis needs to ensure that the Second Order effects and Imperfections are accounted for. STAAD can account for this as prescribed in clause 5.2.2 (3) b – that is, partially by global analysis and partially through the individual stability checks of members according to clause 6.3 of the code. Note that the Global Analysis in STAAD does not in itself accounts for Member Imperfections.

Imperfections:

When we talk about imperfections, we will only talk about global sway imperfections. The local bow imperfections are considered within capacity equations of buckling resistance of members.

Clause 5.3.2 (3) a of the code, equation 5.5 gives the equations for calculating the global sway imperfection in terms of Φ, the initial sway imperfection of the frame. One may choose to model the structure by incorporating this imperfection in the model. However, an easier way to model the initial sway imperfection is to replace the specified imperfection with a system of horizontal loads of value Φ*N_ED. N_ED is the vertical load on the column members of the frame.

These horizontal loads, called the notional loads, can easily be generated in STAAD using the Notional Load Command.

The use of Notional Loads to model the Sway Imperfection of the Frame is discussed in the following example.

Example of Global Analysis including Imperfections:

Let us consider the frame in the following example. The height of the frame is 10.5 metres and the width of the frame is 10.5 metres with four columns in each of the four rows on either side.

The Imperfection calculation is as below:

Φ = Φ₀  α_n  α_m

Φ₀ = 1/200 = 0.005

α_n = 2/(n)0.5 = 0.62 < 2/3

Thus, α_n = 2/3 = 0.67

m = 4

α_m = (0.5 (1+1/m))0.5

     = (0.5 (1+1/4))0.5         

   = 0.79

Φ = 0.005 X 0.67 X 0.79

   = 0.0026

Now, the imperfection can be modelled as horizontal load of magnitude 0.0026* N_ED. N is the axial load on the vertical members resulting from factored vertical dead and imposed load.

   Now, the load items of the Dead Load Case and the Live Load case are specified as    Reference Load Case as below:

DEFINE REFERENCE LOADS

LOAD R1 LOADTYPE Dead TITLE DEAD LOAD

SELFWEIGHT Y -1

JOINT LOAD

17 TO 48 FY -7

49 TO 64 FY -3.5

LOAD R2 LOADTYPE Live TITLE LIVE LOAD

JOINT LOAD

17 TO 48 FY -4

49 TO 64 FY -1.5

END DEFINE REFERENCE LOADS

Now, let us assume a combination of Dead Load and Live of 1.35 DL + 1.5 LL. For imperfection consideration, appropriate Notional Load should also be considered alongside the combination of dead load and Live Load.

Now, the first primary load case defines the Factored Dead Load as below:

LOAD 1 LOADTYPE Dead TITLE DEAD LOAD

REFERENCE LOAD

R1 1.35

The second primary load case defines the factored Live Load:

LOAD 2 LOADTYPE Live TITLE LIVE LOAD

REFERENCE LOAD

R2 1.5

The combination of Dead and Live Loads along with the appropriate Notional Loads in X direction can then be defined as follows:

LOAD 4 LOADTYPE None TITLE 1.35DL + 1.5LL + NOT_X

REPEAT LOAD

1 1.0 2 1.0

NOTIONAL LOAD

1 X 0.0026 2 X 0.0026

Similarly, the Notional Loads in Z direction can be specified as:

LOAD 5 LOADTYPE None TITLE 1.35DL + 1.5LL + NOT_Z

REPEAT LOAD

1 1.0 2 1.0

NOTIONAL LOAD

1 Z 0.0026 2 Z 0.0026

Now, let us specify the PERFORM BUCKLING ANALYSIS to determine the Buckling factors. The Buckling factors is to be determined under Vertical Load only. Thus, we have also specified a load case to determine the corresponding buckling factor.

LOAD 3 LOADTYPE TITLE LOAD CASE TO DETERMINE ALPHA_cr

REFERENCE LOAD

1 1.0 2 1.0

This load case will not be required for subsequent analysis and can be de-activated after the Buckling factors have been determined.

Now the Output file Reports the Buckling factor for the first four modes as below:

CALCULATED BUCKLING FACTORS FOR LOAD CASE       3

       MODE               BUCKLING FACTOR

         1                     24.61027

         2                     37.93287

         3                     66.56160

         4                     88.10634

As we can see, the critical buckling mode has a buckling factor of greater than 10 and hence we can opt for an elastic analysis only.

Now, let us deactivate load case 3 and change the line PERFORM BUCKLING ANALYSIS to PERFORM ANALYSIS.

The final file input information is as below:

STAAD SPACE EXAMPLE PROBLEM FOR UBC LOAD

START JOB INFORMATION

ENGINEER DATE 19-May-15

END JOB INFORMATION

UNIT METER KN

JOINT COORDINATES

1 0 0 0; 2 3.5 0 0; 3 7 0 0; 4 10.5 0 0; 5 0 0 3.5; 6 3.5 0 3.5;

7 7 0 3.5; 8 10.5 0 3.5; 9 0 0 7; 10 3.5 0 7; 11 7 0 7; 12 10.5 0 7;

13 0 0 10.5; 14 3.5 0 10.5; 15 7 0 10.5; 16 10.5 0 10.5; 17 0 3.5 0;

18 3.5 3.5 0; 19 7 3.5 0; 20 10.5 3.5 0; 21 0 3.5 3.5; 22 3.5 3.5 3.5;

23 7 3.5 3.5; 24 10.5 3.5 3.5; 25 0 3.5 7; 26 3.5 3.5 7; 27 7 3.5 7;

28 10.5 3.5 7; 29 0 3.5 10.5; 30 3.5 3.5 10.5; 31 7 3.5 10.5;

32 10.5 3.5 10.5; 33 0 7 0; 34 3.5 7 0; 35 7 7 0; 36 10.5 7 0;

37 0 7 3.5; 38 3.5 7 3.5; 39 7 7 3.5; 40 10.5 7 3.5; 41 0 7 7;

42 3.5 7 7; 43 7 7 7; 44 10.5 7 7; 45 0 7 10.5; 46 3.5 7 10.5;

47 7 7 10.5; 48 10.5 7 10.5; 49 0 10.5 0; 50 3.5 10.5 0; 51 7 10.5 0;

52 10.5 10.5 0; 53 0 10.5 3.5; 54 3.5 10.5 3.5; 55 7 10.5 3.5;

56 10.5 10.5 3.5; 57 0 10.5 7; 58 3.5 10.5 7; 59 7 10.5 7;

60 10.5 10.5 7; 61 0 10.5 10.5; 62 3.5 10.5 10.5; 63 7 10.5 10.5;

64 10.5 10.5 10.5;

MEMBER INCIDENCES

101 17 18; 102 18 19; 103 19 20; 104 21 22; 105 22 23; 106 23 24;

107 25 26; 108 26 27; 109 27 28; 110 29 30; 111 30 31; 112 31 32;

113 33 34; 114 34 35; 115 35 36; 116 37 38; 117 38 39; 118 39 40;

119 41 42; 120 42 43; 121 43 44; 122 45 46; 123 46 47; 124 47 48;

125 49 50; 126 50 51; 127 51 52; 128 53 54; 129 54 55; 130 55 56;

131 57 58; 132 58 59; 133 59 60; 134 61 62; 135 62 63; 136 63 64;

201 17 21; 202 18 22; 203 19 23; 204 20 24; 205 21 25; 206 22 26;

207 23 27; 208 24 28; 209 25 29; 210 26 30; 211 27 31; 212 28 32;

213 33 37; 214 34 38; 215 35 39; 216 36 40; 217 37 41; 218 38 42;

219 39 43; 220 40 44; 221 41 45; 222 42 46; 223 43 47; 224 44 48;

225 49 53; 226 50 54; 227 51 55; 228 52 56; 229 53 57; 230 54 58;

231 55 59; 232 56 60; 233 57 61; 234 58 62; 235 59 63; 236 60 64;

301 1 17; 302 2 18; 303 3 19; 304 4 20; 305 5 21; 306 6 22; 307 7 23;

308 8 24; 309 9 25; 310 10 26; 311 11 27; 312 12 28; 313 13 29;

314 14 30; 315 15 31; 316 16 32; 317 17 33; 318 18 34; 319 19 35;

320 20 36; 321 21 37; 322 22 38; 323 23 39; 324 24 40; 325 25 41;

326 26 42; 327 27 43; 328 28 44; 329 29 45; 330 30 46; 331 31 47;

332 32 48; 333 33 49; 334 34 50; 335 35 51; 336 36 52; 337 37 53;

338 38 54; 339 39 55; 340 40 56; 341 41 57; 342 42 58; 343 43 59;

344 44 60; 345 45 61; 346 46 62; 347 47 63; 348 48 64;

MEMBER PROPERTY EUROPEAN

101 TO 136 201 TO 236 PRIS YD 0.4 ZD 0.3

301 TO 348 TABLE ST IPEA400

DEFINE MATERIAL START

ISOTROPIC MATERIAL1

E 2.5e+007

POISSON 0.156297

DENSITY 24

ISOTROPIC MATERIAL2

E 2.05e+008

POISSON 0.292124

DENSITY 77

END DEFINE MATERIAL

CONSTANTS

MATERIAL MATERIAL1 MEMB 101 TO 136 201 TO 236

MATERIAL MATERIAL2 MEMB 301 TO 348

SUPPORTS

1 TO 16 FIXED

DEFINE REFERENCE LOADS

LOAD R1 LOADTYPE Dead TITLE DEAD LOAD

SELFWEIGHT Y -1

JOINT LOAD

17 TO 48 FY -7

49 TO 64 FY -3.5

LOAD R2 LOADTYPE Live TITLE LIVE LOAD

JOINT LOAD

17 TO 48 FY -4

49 TO 64 FY -1.5

END DEFINE REFERENCE LOADS

LOAD 1 LOADTYPE Dead TITLE DEAD LOAD

REFERENCE LOAD

R1 1.35

LOAD 2 LOADTYPE Live TITLE LIVE LOAD

REFERENCE LOAD

R2 1.5

LOAD 3 LOADTYPE TITLE LOAD CASE TO DETERMINE ALPHA_cr

REFERENCE LOAD

1 1.0 2 1.0

LOAD 4 LOADTYPE None TITLE 1.35DL + 1.5LL + NOT_X

REPEAT LOAD

1 1.0 2 1.0

NOTIONAL LOAD

1 X 0.0026 2 X 0.0026

LOAD 5 LOADTYPE None TITLE 1.35DL + 1.5LL + NOT_Z

REPEAT LOAD

1 1.0 2 1.0

NOTIONAL LOAD

1 Z 0.0026 2 Z 0.0026

PERFORM ANALYSIS

FINISH

Problem Description

After installing RAM Structural System x64, the program fails to open. Attempting to open either the desktop or Start menu shortcut for RAM Structural System does nothing.

Steps to Resolve

This is a known issue (TR 4020) that affects only some workstations running a 64-bit operating system. Until the issue is resolved, install the 32-bit release as a workaround.

The following steps should be followed to apply the workaround:

1. Uninstall RAM Structural System x64 from either the Add or Remove Programs (Windows XP) or Programs and Features (Windows Vista/7/8) control panel.
2. Install RAM Structural System. The installer starts with ramm instead of ram (e.g. ramm14060100en.exe) and does not include 64 in the name (e.g. ram6414060100en.exe).

The issue also occurs when the Ram Modeler license is disabled.

Error or Warning Message

When opening RAM Elements, the following error occurs:
HWLockDLL internal error. Unable to get license.

Explanation

HWLockDLL is a licensing library used by some RAM programs to communicate with the Bentley IEG License Service. The error will occur if the 32-bit release of the Bentley IEG License Service is not installed. This can occur if the 64-bit release, known as Bentley IEG License Service x64 is installed instead. Programs that are 32-bit will only communicate with the 32-bit release of the Bentley IEG License Service.

Solution

1. Updating to the latest version of RAM Elements and configuring the license will resolve the issue.

If you are unable to upgrade at this time, please follow the steps as stated below.

      2. Please open the Add or Remove Programs (Windows XP) or Programs and Features (Windows Vista/7/8) control panel, and ensure that the Bentley IEG License   Service is installed.

To locate the IEG License Service using the new Fulfillment Center, just start typing IEG in the search box.

Important: RAM Elements and other 32-bit programs cannot communicate with Bentley IEG License Service x64.

If the above does not resolve the problem, remove the HWLockDLL.dll file from the following location:

C:\Program Files (x86)\Common Files\Bentley\Engineering\RAMHWLock

Then, perform a repair of the RAM Elements installation to restore the file.

Server Based Installations

Typically we recommend that the software be installed on each PC that needs to use it. In at least one case on a Windows 2012 terminal server, a user was able to get Ram Elements to function, but only after manually registering the HWLockDLL. To do that go to Start - and type "Run" + enter to get the command prompt. On the command prompt execute:

regsvr32  "C:\Program Files (x86)\Common Files\Bentley\Engineering\RAMHWLock\HWLockDLL.dll"

If it succeeds, a message should appear like this:

See Also

[[RAM Connection Support Solutions]]

Overview

This page is the landing page for user help for modeling design strips in RAM Concept. The page is divided into two main sections: Tech Notes and Frequently Asked Questions. The Tech Notes section includes links to web pages with in-depth discussion of other issues relating to design strips. The Frequently Asked Question section includes common questions relating to design strip modeling and properties.

It is recommended that users become familiar with the “Defining Design Strips” chapter in the RAM Concept Manual, which contains additional guidelines on design strips that are not included here.

Tech Notes

        Generating Span Segments

Defining Manual Design Strip Boundaries

        Cross Section Trimming

        Design Strips and Slab Openings

Frequently Asked Questions

When should design strips be modeled with column and ½-middle strips and when should they be modeled as full-width column strips?

RAM Concept uses a finite element analysis to determine design forces. These forces are determined by integrating (or averaging) the finite element forces across the width of the column or ½ middle strips. The wider the strip, the more the design force is averaged and the greater the difference to the peak design force in the strip.

Figure 1 shows a typical moment distribution. Note that the moments are highest near the column and decrease toward the middle of the span. Using the column/middle strip approach forces the program to integrate moments with similar magnitudes across the width of the strip. The design moment for the column strip will be closer to the peak moment than if a full-width design strip was used. It is important to remember that the use of column and middle strips only affects the integration of forces, but does not affect load distribution in the finite element analysis.

 Figure 1. Typical Moment Distribution Across Column and Middle Strips

In some cases, it may be desirable to use design strips modeled as full-width column strips instead of column and two half middle strips. If two columns are close together, for example, the moment distribution may not vary significantly over the width of the strip (see Figure 2). Averaging moments over the full tributary width may be justified.

 Figure 2. Typical Moment Distribution for Closely Spaced Columns

It is also acceptable to define full-width strips for the column strips and full middle strips manually in lieu of using column strips and ½ middle strips (see Figure 3). This allows for the middle strip to be designed as one strip instead of two separate strips. This approach may be the best option when the ½ middle strips are narrow. To model full-width middle strips, the span segments must be modeled independently using the span segment tool. RAM Concept will not generate the span segments for these strips automatically. Where the column support is large, you may want to may want to set the support width to the column dimension for the full-width column strip and 0 for the full-width middle strip. Assuming that the span segments are extended to the centerline of the support, this will force the program to locate the first cross-section at the support centerline as opposed to the centerline of the column (see Figure 3).

 Figure 3. Full-Width Column and Middle Strips

Full-width column strips are typically used for post-tensioned slabs for the following reasons:

• Capacity calculations of post-tensioned slab have generally assumed that the precompression in the slab is distributed over the full tribuary width.
• Tendons are often banded along column grid lines.
• The column/middle strip approach was developed for use for the approximate two-way slab method discussed in Chapter 13 of ACI 318-05. These do not apply to prestressed slabs per ACI 318-05 18.2.1.

Some design codes require column and middle strips for PT design and require some distribution of tendons in both the column and middle strips. Problems can occur in PT slabs with banded tendons if a column/middle strip layout is used and a tendon does not intersect the middle strip. See the following web page for more information:

Balance and Hyperstatic Loading

Are there any recommendations for modeling design strips for beams?

For design strips parallel to the beam, it is best to align the design strip with the axis of the beam. If the strip is skewed slightly, then the Orient Span Cross-Section tool should be used to keep the cross-sections normal to the beam.

Engineering judgment should be used to model the design strips perpendicular to the beam. Beams can be supported by columns or other beams. The end points of the span segment should be defined at the centerline of each support. When beams are supported as other beams, it will be necessary to uncheck the box for “Detect Supports and Edges Automatically” in the Strip Generation tab of the Design Strip properties dialog and manually enter support widths (See Box 1 in Figure 4). The Support Width defines where the first (and last) cross-section is located, i.e. the critical section for moment design. Typically, the critical section is taken at the face of the supporting column or beam, although some engineers take the critical section at the centerline of the support. When the critical section is taken at the face of the support, it is best to model the support width 2” larger than wider than the actual width to avoid any rounding or snapping errors. Note that when design strips extend past an intersecting beam, a portion of the cross-section may be trimmed by the inter cross-section slope limit. See the RAM Concept manual for more on this type of cross-section trimming.

Typically, design strips for beams have the Column Strip Width Calc set to “Code T-Beam” (See Box 2 in Figure 4) and the CS Design System set to “Beam” in the Strip Generation tab (see Figure 5). This ensures that the column strip includes the beam and its effective flange width and that the cross-sections are designed using the ACI provisions for beams as opposed to slabs. The Middle Strips tab will typically have the box for “Middle Strip uses Column Strip Properties” unchecked (see Box 4 in Figure 6). This allows for the beam and slab to be designed with different bar sizes. The MS Design System should be set to “Two-way slab” so that the code provisions for slab design are used for design (see Box 5 in Figure 6).

When modeling one-way slabs, it is convenient to use the “Design Column Strip for Column + Middle Strip Resultants (See Box 3 in Figure 4). When selected, forces are integrated separately over the column strip and each half middle strip, then added together, and used to design the column strip. This allows for the beam and its effective flange to be designed for the full design strip forces.

Figure 4. Typical Strip Generation Settings for Beam Design Strips

     Box 1. Option for manually defining support widths

     Box 2. Option for setting column strip width calc to "Code T-beam"

     Box 3. Option for designing column strip for column + middle strip resultants

Figure 5. Typical Column Strip Settings for Beam Design Strips

Figure 6. Typical Middle Strip Settings for Beam Design Strips

     Box 4. Option for choosing different properties for middle stips

     Box 5. Option for selecting design system for middle strips

Why does the Status Plan on the Design Status Layer show failures for ACI 318 18.3.3 (or other post-tension concrete code provision when the slab is a mild reinforced concrete slab and not a post-tensioned slab?

There is an option in the Default Span Properties dialog that controls whether the design strip is designed as a post-tensioned slab or a mild reinforced slab (see Figure 7 below). To change the setting for span segments that have been modeled previously, do the following:

1. Open the Latitude Design Spans Plan on the Design Strip layer.
2. Use the Selection Tool to select all span segments on the plan.
3. Right click in the plan window and choose "Selection Properties" from the menu to open the Default Span Properties dialog.
4. Click on the General tab.
5. Uncheck the box for "Consider as Post-Tensioned" (see Figure 7).
6. Repeat steps for the Longitude Design Spans Plan on the Design Strip layer.
7. Reanalyze model.

Figure 7. Consider as Post-Tensioned Option

See Also

Generating Span Segments

Structural Product TechNotes And FAQs

When analyzing my STAAD.pro file, I am getting an **ERROR** SECTION PROPERTIES NOT ENTERED FOR MEMBER xxx. However when I go to Select > By Missing Attributes > By Missing Property I get a message No entity with missing Property is found. Why is the analysis stopping with errors in that case  ?

Most likely you have defined the properties using the GUI. However when the software is writing down the corresponding commands in the input command file, it is writing it at the incorrect location. So this is not a problem with your input but it is a software problem as it is failing to write the commands internally at the right location. Our development team is continuously making an effort to address these sort of issues but unfortunately sometimes we still do encounter such occurrences.

The GUI is not flagging this as an error as the properties are actually in there. The engine, which reads the commands sequentially, on the other hand is failing to find the property and stopping at a point beyond which it cannot proceed without the property information. For example if the MEMBER PROERTY is recorded after LOAD CASE or after the PERFORM ANALYSIS commands then the engine would stop with such errors. The best way to address this is to go to the input editor ( Edit > Edit Input Command File ) and search for the MEMBER PROPERTY information and ensure that all the property blocks are at the right location.    

Description

When I try to create and ISM in STAAD, I get the following errors. Unable to cast 'STAAD.Pro' COM object to 'OpenSTAAD' object. Check if 'OpenSTAADUI.tb' type library file is properly registered. Also No
STAAD filename is provided. Unable to connect to 'STAAD.pro' instance. Check if STAAD.Pro application is running.

Solution

To solve the issue, manually register the OpenSTAADUI.tlb file.  You can do this by following these steps:

1. Go to the Windows Start menu and select Run:

     2.  Type “cmd” in the Run dialog box then click OK.

     3.  You will see the command prompt dialog box appear.

  4. Type the folder directory “CD C:\SProV8i SS5\STAAD”, click on “Enter”

  5. Type “regsvr32 OpenSTAADUI.tlb”, click “Enter”.  You should see a dialog box appear indicating   that the file has been registered.

Once this is finished launch STAAD.pro and you should not receive the message anymore..

Error or Warning Message

When opening STAAD.Pro, the following message can occur:

Unable to activate RSS Feed connection

Explanation

This message indicates that STAAD News Feed cannot be activated successfully. In such situation, STAAD News are not shown in the start-up window of STAAD.Pro.

How to Avoid

1. In most cases, it should be enough to install BentleyRSS.msi file, which can be downloaded from here.

2. If installation of BentleyRSS.msi file does not help, check if you are able to go to the page http://feeds.rapidfeeds.com/8131/ or not. If not, then there is potentially some firewall/security in your network that is blocking the communication when STAAD.Pro is trying to communicate with the RSS feed page.
   
   If you are able to connect to the webpage through Internet Explorer, it means that specifically when STAAD.Pro tries to access information over the internet, that particular communication is being blocked. You may check your firewall settings in your network and add STAAD.Pro (C:\SProV8i\STAAD\Staadpro.exe) to the list of Exceptions. If you have a proxy server in your network then check if that is blocking the communication or not.

The same solution can also be used to correct a problem with the RSS Feed in Ram Manager 14.06 or later.

Error or Warning Message

Error "LoadLibrary failed with error 126: The specified module could not be found" occurs while clicking on 3D Rendered View icon in STAAD.Pro or while going to Beam -> Stresses tab in the Postprocessing mode.

How to Avoid

a. Click on Start, click All programs, click Accessories, right click on Command prompt and select Run as administrator. 

b. Type in the following commands and hit enter after each command 

      Cd /d C:\Windows\System32

      Copy atioglxx.dll .dll

c. Exit the command prompt and check for the issue.

In most cases the "Diffutils.dll file ..." errors is related to insufficient/incorrect permissions to registry keys. Googling the error can navigate one to the various explanations, and here is the link to the webpage where the causes and possible solutions are explained best:

http://www.solvusoft.com/en/files/missing-not-found-error/dll/windows/windows-software-developer/diffutils-dynamic-link-library/diffutils-dll/