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 or transferred by one-way decking.

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 analysis 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 find the tributary point load distributed to the beam if one-way decks are used.
• 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 load 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!

I'm trying to design a concrete beam with RAM Concrete. When I analyze the structure I get a general warning "Section must be designed as a Deep Beam per ACI 318-11 for shear". Where do I assign the properties as a deep beam or does RAM Concrete not preform deep beam designs? 

Are the applied surface loads cumulative?

No, in RAM Structural System only the top applied surface load counts. The underlying loads are not deleted however, so if you delete the top load you can see the original load underneath. If too many load layers are applied to a model, a polygon error can occur when processing the loads. For this reason it is always best to remove any existing surface loads before modeling new layers.

Also note, this is different than the behavior in RAM Concept. In that program, overlapping surface loads are cumulative. Consequently, when Direct Gravity loads are imported from RAM SS into Concept, they are converted into equivalent separate polygons that do not overlap.

Is the structure self-weight included in the loads?

That depends on the settings under RAM Manager - Criteria - Self-Weight. Here the user can automatically include beam, column, wall or deck self-weight. Note, open web steel joists self-weight is never included.

On the right hand side of the dialog box are the settings for self-weight as it applies to the building mass which is used for seismic loads, dynamic analysis and for P-Delta calculations.

For composite beam design, the self weight is always considered part of the Construction Dead Load. Hence, if all the self weight options are turned on, and there is no other load present during construction, the user applied CDL might be zero

In order for the steel gravity beam and column self weight mass to be considered in RAM Frame, it is imperative that those modules be run first, using the design-all process. So long as the RAM Manager indicates a green light next to each of those modules, RAM Frame should have the latest member self weight data available. Freezing the design of all gravity beams and columns is another way to ensure that member self weights are always considered.

Note, in RAM Frame, under Loads - Masses, the program calculated diaphragm mass totals can be overridden with User Specified values, normally using calculated masses is advised. There is a similar dialog box for the total Gravity Loads which is used to determine program generated notional loads.

Is the additional weight of concrete due to beam sag or "ponding" considered?

No, the self-weight of the deck is based on the thickness and weight parameters set in the Modeler - Deck Properties. When beams sag under the weight of the deck it is a common practice for the topping concrete to be leveled off which adds additional weight to the system assuming it's not cambered or shored. This additional weight should be incorporated into the applied construction dead loads (and masses).

How are partition loads handled.

The Partition Load is an additional Live Load; it is treated as an unreducible Live Load and will not be reduced. It is in addition to the loads specified as Live Load. Partition loads are defined variously by the Codes, some as Dead Load and some as Live Load. For those codes that define Partition loads as an unreducible Live Load, those should be specified here. For those Codes that define Partition loads as a Dead Load or as part of the regular Live Load, those should be included as part of the Dead Load or Live Load accordingly.

Unlike construction live load, the partition live load is not a portion of the total live load entered. You can apply 0 Live Load and still apply 15 psf Partition Live load, for example.

Partition loads are not automatically included in the seismic mass. The total Mass DL should be increased to account for partition weight as required by the code for seismic loads.

How is the self weight of Concrete Beam determined?

The program calculates rectangular beam unit self-weight based on the area of the beam times the "Unit Weight of Self weight". The other "Unit Weight" parameter is only used in calculating the elastic modulus, E, of the member.
The Concrete slab can independently be included in the self weight, so in cases where there is a concrete slab and rectangular concrete beams the weight of the concrete times the thickness of the slab and the width of the beam is double counted.

 
To alleviate this problem, "T" shaped beam sections are handled differently. With T beams, it's only the area of the stem below the slab that is applied as the beam self weight.

.

Why are my Roof Live loads ignored in the design?

RAM Structural System currently considers Snow OR Roof LL, but not both at the same time. In RAM Manager under Criteria - Members loads there is a toggle to select which the program should consider. Set the toggle to “Consider snow loads, Ignore roof live loads” when snow loads are modeled.

Note: Live Reducible, Unreducible and Storage type loads are always considered, it is only the Live - Roof type loads that are excluded when the option to consider snow loads is turned on.

Are my snow loads automatically added to the building weight for seismic load determination?

No, the program only uses the assigned Mass Dead Loads plus whatever self-mass options are turned on under RAM Manager - Criteria - Self weight when determining the total building mass or weight used in Seismic load determination (and in P-Delta calculations). The user should increase the Mass DL of applied surface loads to account for the weight of the snow load (or a percentage of the weight as required.

Note, the provided templates for load combinations do correctly consider snow load acting simultaneously with Dead, Live and Seismic loads, however.

This also applicable to Storage Live Loads, even if the magnitude entered for the Storage Live load is large (e.g. > 125 psf) no portion of the storage live load is automatically considered in the seismic mass. The user must increase the Mass DL (or manually alter the masses in Ram Frame) when part of a storage live load needs to be added to the seismic mass.

How can I apply a drift snow load?

Within the snow loads, only the top load counts. Since only the top snow load counts, the drift snow load should typically taper down from the max value to the flat-roof snow load as a minimum. The program gives a warning when any portion of the sloping plane of snow load is 0 or less magnitude.

In general, it’s best to define snow drift loads with M1 and M2 set to the highest value, and M3 set to the flat roof level. Then the loads can be applied in rectangular or trapezoidal areas as required. In the image below, the total snow load on the left is 50 psf tapering down to 30 psf on the right. This would be used in conjunction with a flat roof snow load of 30 psf applied first to the whole roof.

See Also

RAMSS Seismic Loads FAQ

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!

Problem Description

In the V8i releases listed below, the User Name, which is shown in the header of program output, is based solely on the Windows login name.

• Microstran 09.20.01.18
• Limcon 03.63.01.11
• MsTower 06.20.01.08

In some situations, the user name may also include the suffix, "Not for Production Use"

Solution

An update release for all three applications is in progress and will have an option under File -> Configure -> General to override this and manually specify the desired User Name to show on the output.

build numbers with the solution; 

• Microstran 09.20.01.21
• Limcon 03.63.01.14
• MsTower 06.20.01.09

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

How can I resolve an analysis warning related to Distributed Loads?

During analysis, the follow error or similar can occur:

[Warning] Distributed load "1" in member "1" at load condition "DL=Dead Load" is zero, it will not be considered during the analysis.

When loads are generated by the program from areas or from importing from RAM Structural System, in particular, you may end up with loads that are defined (they have a direction and a category), but the magnitude is zero. It’s also possible for the user to start entering loads but then never enter any magnitude.

To fully correct the issue, the member loads spreadsheet for the load in question needs to be cleaned up so that load directions and categories are only defined when the load magnitude is > 0. Be aware this spreadsheet is wide to accommodate multiple line loads per member and the problem may not be for the first load.

See Also

RAM Elements Load Combos FAQ

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!

Why are the yellow lines for members shortened at the nodes? 

The lines are drawn slightly short of the nodes so that the nodes are clearly visible in line mode.

In the fully rendered view you can see the members full length (or shrunken)

I have a small model and the support icons appear very large, how can I make them smaller?

The size of the nodal support, member hinge and other icons is typically adjusted based on the overall size of the model, but the user can force the icons to appear larger or smaller. 

To control the size of the icons go to the e menu (file menu) and pick General Configuration. On the Display tab, uncheck the box for  Data and Results - Automatic Scale and then enter a number >1 to make the icons larger, <1 to make them smaller.

How can I rotate the view?

In order to rotate the view, click and hold the right mouse button, then drag the mouse to dynamically rotate the view. Note, in RAM Elements, the Y axis typically points upward and this axis is always plumb on the screen.

If you find the rotation is too fast or too slow for your liking, go to the e menu - General Configuration and on the General tab, adjust the Mouse rotation sensitivity slider.

How can I Save a View?

In Ram Elements you can save a particular type of view including the angle of the view, the zoom, perspective settings and display options. To do so, first adjust the graphic as desired, then right click on the view and choose Customized Views - General - Create. Provide a name for the view, check the desired attributes to save and click Create.

These general views work across all files.

The program also allows you to save model-specific views. To do so, again adjust the view the way you like it. Then right click on the view and pick Customized Views - Current Model.

In addition to the attributes mentioned above, Current Model views also store the active selection set and any hidden members for instant recall.

To recall a saved view, simply right click on the graphic and pick the saved view by name from the Customized Views.

How can I make the on screen text easier to read?

At the bottom right corner of the Ram Elements window are the controls for increasing or reducing the text size on screen. Just to the left of that is the control for units.

By not Showing the units more significant digits are shown, filling roughly the same screen area.

Using Larger or Smaller units under Units Configuration can affect the displayed number of digits. For example. if the axial force in a column is -2471.45 pounds, switching to kips changes the display to -2.47 kips which is shorter.

Regretfully, there is no other user control over significant digits displayed.

How can I view the design properties, things like unbraced length?

From the View Ribbon menu, in the Design Toolbar, select Design Properties and one or more of the options:

• Effective length factors (i.e. K22 and K33)
• Axial and torsional unbraced lengths (i.e. L22 and L33)
• Flexural unbraced lengths (i.e. Lbpos and Lbneg)

Note, for unassigned default values (0) nothing will be shown on screen. Only user specified values are plotted.

How do I change the scale of the deflection multiplier?

Click on RAM Element button in the top left corner and click on the button 'General configuration'. Then select tab Display and change the deflection multiplier as shown in the screenshot:

See Also

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!

RAM Elements AISC 360 Stability Analysis and Design

General

Chapter C of the AISC specification (2005 and later) covers stability analysis and design. This document discusses how the requirements are met in RAM Elements.


Analysis and Design Using General Second-Order Elastic Analysis

RAM Elements has the ability to perform a general second-order elastic analysis per AISC 360 C2.1. It is an option in the Process tab – Analyze Model – Analysis tab. This method captures big P Delta effects but will not capture small P delta effects unless the individual members are segmented into smaller pieces in the finite element analysis. For example, imagine a column that is 15’ long. If it is modeled as a 15’ long member, small P delta effects are not captured. If it were modeled as five 3’ segments, small P delta effects are captured because there are additional nodes between the ends of the member. Currently, there is no option to automatically segment the members this way in the finite element model and it must be done manually. Please note, if you segment a member, be sure to specify the proper unbraced lengths in the steel design parameters. The unbraced lengths will always default to the physical length of the member.

AISC 360 C2.2a(2) requires an analysis for ASD design to be carried out under 1.6 times the ASD load combinations and the results divided by 1.6 to obtain the required strengths. It is currently not possible to divide the results by 1.6 in RAM Elements. Therefore, you must use LRFD.

AISC 360 C2.2a(3) requires notional loads to be considered in the gravity only combinations unless initial out-of-plumbness has been modeled. Currently, notional load cases do not exist in the program as a predefined load type. They need to be manually modeled as unique load cases and manually accounted for in the load combinations. For example, imagine you have a structure with dead load and live load. One would create a notional dead and live load cases in two independent directions. Let’s assume they were called NDX, NDZ, NLX and NLZ. For the typical gravity combinations 1.4 DL and 1.2 DL + 1.6 LL, you would need to create a total of four load combinations to account for the notional loads.

1.4 DL + 1.4 NDX
1.4 DL + 1.4 NDZ
1.2 DL + 1.2 NDX + 1.6 LL + 1.6 NLX
1.2 DL + 1.2 NDZ + 1.6 LL + 1.6 NLZ

AISC 360 C2.2a(4) discusses effective lengths. This Wiki page discusses how effective lengths are implemented in RAM Elements. Effective Lengths in RAM Elements

A practical example for the general second-order elastic analysis is discussed here.  RAM Elements AISC 360 Stability Example

Other Limitations

It is not possible to run P Delta with dynamic load cases. Second order effects must be accounted for by hand.

Currently, the Direct Analysis Method discussed in AISC 360 Appendix 7 is not implemented in RAM Elements V12. Therefore, structures with a second order drift to first order drift ratio exceeding 1.5 cannot be designed in RAM Elements per AISC 360 C2.2.

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!

Effective Length Factors in RAM Elements

General

AISC effective length factors (K33 and K22 factors) can be automatically calculated in V12.  This document discusses the implementation prior to V12 and the changes made in V12.  The value of K Torsion did not change.  It defaults to K=1.0 unless another value is entered in the AISC steel design parameters.

Old Implementation

If the K22 or K33 field was left blank or set to zero in the AISC Steel Design Parameters, the program automatically assumed K = 1.0.  There was tool buttons to calculate K33 and K22. If this tool was selected, the program used the following equations to calculate K.

Members Assigned as Sway
K = SQRT((1.6*GB*GA+4*(GB+GA)+7.5)/(GB+GA+7.5))

Members Assigned as Non-Sway
K = min(min(0.7+0.05*(GB+GA),0.85+0.05*min(GB,GA)),1.0)

GA and GB values depend on member stiffness as described by specification commentary.  Values that were theoretically infinity (pinned) were assumed to be 10.  Values that were theoretically fixed were assumed to be 1.

V12 Implementation

V12 added new Value Type K33 and Value Type K22 parameters.  When the Value Type is set to ‘None’, the program functions as it did in previous versions and K will be assumed to equal 1.0 unless a value is entered for K.  If the Value Type is set to ‘Recommended’, the program will use the recommended approximate values in Table C-C2.2 in the 13th Ed AISC Manual.  If the Value Type is set to ‘Theoretical’, the program will use the theoretical approximate values in Table C-C2.2 in the 13th Ed AISC Manual.

When the tool button in the steel design parameters is used to calculate K, the alignment charts in Chapter C of the commentary in the 13th Ed AISC Manual are used.  This method considers the stiffness of rigidly connected members and uses the equations below.  The tool button cannot be used when the multiple unbraced lengths (L33 and L22) are entered for the member.

Members Assigned as Sway
(GA*GB*(Pi/K)^2-36)/(6*(GA+GB))-(Pi/K)/(tan(Pi/K)))=0

Members Assigned as Non-Sway
(GA*GB/4)*(Pi/K)^2+((GA+GB)/2)*(1-(Pi/K)/(tan(Pi/K)))+(2*tan(Pi/(2*K)))/(PI/K))=0

GA and GB values depend on member stiffness as described by specification commentary.  Values that were theoretically infinity (pinned) were assumed to be 10.  Values that were theoretically fixed were assumed to be 1.

Special Considerations

The automatic calculation of K is based on the physical length of the member.  Therefore, members framing into intermediate nodes along the member have no impact on the calculated effective length.  For this reason, it is best to segment the member so the physical length matches the unbraced length.

When 2D frames are designed, the out-of-plane effective length factor will be calculated for the columns unless a value is entered in the steel design parameters or the out-of-plane value type is set to ‘None’.  Typically, the calculated value would be incorrect and the effective length should be assumed to be 1 for the out-of-plane direction.

There are many instances where the effective length method should not be used and K should equal 1.0.  The program does not attempt to determine these conditions and will always calculate a value based on the parameters and the analytical model.  For example, members with theoretical pinned ends (GA = GB = 10) will always have a calculated effective length of 3.01 for sway frames and 0.96 for non-sway frames.


Practical Example

Consider a simple portal frame with 15’ long W12X96 columns and a 20’ long W21X83 beam.  Assume the bases of the columns are pinned and there are no releases at the top of the column or ends of the beam.  The column is oriented such that the beam frames into the column flange (strong axis bending).

The frame would be classified as sway in the plane of the frame (frame type 2).  In the out-of-plane direction, the K22 value should be assumed to be 1.0 since the frame will lean against the diaphragm or some other support for stability.  Do not simply set frame type 3 to non-sway.  The Value Type K22 should be set to ‘None’.  It is also appropriate to set K33 for the beam to 1.0 or assign Value Type K33 as ‘None’.

If the tool button is used to compute K33 for the columns, the equations below are used.  Looking at the figure C-C2.4 in the 13th Ed AISC manual, K should be around 1.8.  The equation below is nearly zero when K = 1.81.  That matches the value calculated by the program when the tool button is used in the steel design parameters worksheet.

GA = (EI/L column) / (EI/L beam)
GA =( 29000*833/15) / (29000*1830/20) = 0.607

GB = 10 Assumed at pinned end

(0.607*10*(Pi/1.81)^2-36)/(6*(0.607+10))-(Pi/1.81)/(tan(Pi/1.81)))=0.01

When Value Type K33 is set to ‘Recommended’ for the columns, K33 will be assumed to be 2.1 is indicated in Table C2-2.2(e).

When Value Type K33 is set to ‘Theoretical’ for the columns, K33 will be assumed to be 2.0 is indicated in Table C2-2.2(e).

Does the steel design impose a limit on the slenderness ratio, KL/r?

No, but if the KL/r ratio of a compression member exceeds 200, or if the L/r ratio of a tension member exceeds 300, you will get a warning in the steel design report (and a yellow status color on screen using View - Status). Here's an example from the concise steel report:

Design code: AISC 360-2005 ASD

Member : 3 (BC)
Design status : With warnings

DESIGN WARNINGS

- The slenderness ratio KL/r about major axis of the member in compression should not exceed 200
- The slenderness ratio KL/r about minor axis of the member in compression should not exceed 200
- The slenderness ratio L/r of the member in tension should not exceed 300

These warnings can be totally suppressed by not checking the option, "Include slenderness recommendations" in the Process - Design dialog.

See Also

Steel Unbraced Lengths in RAM Elements [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!

What is the load combination "Type" for?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

See Also

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!

Problem Description

On some machines, the error message below is produced followed by a program crash during the design process when a model is opened by one of the following methods:

1. Double-clicking on the file in Windows Explorer.
2. Clicking on a recent model button on the Welcome Screen.

Steps to Resolve

This crash should be resolved with Ram Elements release 13.03.00.117. For earlier versions, please use one of following to work around the problem:

Work Around #1: Open model inside RAM Elements

First, launch the program from a desktop shortcut or a link in the Windows Start Button. After the program opens, click on the RAM Elements button in the upper right corner of the program window and then click on "Open a Model" or simply click on the "Open a Model" button at the top of the screen. See screen capture below:

Work Around #2: Disable Welcome Screen

The Welcome Screen identified below appears when the program is launched. After launching the program, the Welcome Screen can be opened by clicking on the Help button in the upper right corner of program window (see screen captures below):

In the Welcome Screen, uncheck the box to the left of Welcome Screen in the lower left corner to disable it.

After disabling the Welcome Screen, close out of the program. Then, open a model by double-clicking on a file in Windows Explorer and the crash will no longer occur.

After disabling the Welcome Screen, you will no longer see news information on program updates and other important items when opening the program. The Welcome Screen can be opened anytime by clicking on the link in the Help menu. The news information can also be found on the following web page:

http://feeds.rapidfeeds.com/8826/

See Also

Structural Product TechNotes And FAQs

RAM Connection Crash

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!

Can the edges of shells be pinned or hinged?

Regretfully no, the shell edges are always continuous or fixed to all the objects that connect to them. In cases where you do not want the shells to transfer out-of-plane bending moments to the supports, like an edge beam or wall, there are only a few options:

1. Make the shells thinner. Since the out-of-plane inertia relates to the thickness cubed, reducing the thickness quickly reduces the out-of-plane stiffness. An increase in the shell material E value can counteract this reduction for in plane shear and axial stiffness.
2. Release the supporting member. Sometimes you can release the supporting beam, in torsion for example, to prevent the development of out-of-plane moments at the edge of the supported shells.
3. Separate the edge of the shell from the support, then connect the two together periodically with short members. These connector members can then be released in any of the 6 degrees of freedom to achieve the desired connectivity.

    

How can I report the flexural area of steel required for shells in Ram Elements?

For shell elements that are primarily subject to out of plane bending, Ram Elements can provide output for the area of steel required in the two principal directions per ACI 318-05.

The shells must be concrete and the model must include design combos to take advantage of this feature fully. Mechanical cover for the shells should also be assigned in the Shells - Materials spreadsheet.

To see the output on screen first select the desired combo at the bottom and then use View - Stresses to see stress contours. In the list of stress options, pick As 1 or As 3 top or bottom.

To get a report of the same information use Output - Analysis - Analysis Results - and select the last option "Flexural reinforcement in shells", Be sure to select the desired combo or combos on the right and then OK. 

Obviously having shells with local axes aligned to the direction of the reinforcement is critical for making this output useful.

Also note, this does not take into acount shear design nor the effects of axial tension or compression acting on the shells.

Can Ram Elements be used to design a mat foundation on soil?

Yes, one of the keys to modeling the mat foundation is to define a regular mesh. Since the nodes of the mesh need to be supported by vertical compression-only springs, we need the mat to be manually meshed. Using a regular size mesh will help so that the tributary area of each node is fairly constant allowing you to use the same spring stiffness.

The assigned spring stiffness should be derived from the soil subgrade modulus and the average shell area. Note, the spring units are in force/length, e.g. kip/in, meaning how many kips of compression at this point does it take to yield 1 inch of deflection. To make the springs compression-only, just check the Compression only - TY box (assuming Y is vertical).

In order to insure stability some soil friction resistance or edge restraint should also be modeled. Modeling the self-weight of the foundation may also be required for stability (this can be modeled using the Gen - Self weight option). If self weight is included as part of the dead load, also make sure that the dead load is used in all of the combos. Because the model includes compression-only springs, iterative analysis is required. It may be that the model is stable for combinations, but not for the lateral load cases alone, but that's OK so long as the combos all produce valid results.

A sample file can be found here.

The method above outlines how to get steel requirements for the shells. Bearing stress results can be derived from the spring reactions.

For something a little more automated, consider Ram Concept. 

Can I apply a varying pressure on a shell?

No, pressure loads on shells are always uniform and normal to the shell surface in Ram Elements. Mesh the shell into smaller pieces in order to create a stepping pressure to approximate a varying force (e.g. due to soil or wall pressure).

How can I apply a point load somewhere on a shell?

You can apply a nodal load anywhere on the surface of the shell and that load will be resisted by the meshed elements of the shell. All that is required is to add a node at the location of the load.

If the load is close to the edge, put the node right at the edge to avoid a tiny mesh between the node and the edge. Ram Elements - Meshing Errors [TN]

Make sure you have the option to segment shells turned on under Process - Analyze - Finite element model tab:

Also make sure you are running version 13.00.03.45, this is a fairly recent enhancement to Ram Elements.

Why are the corner node reactions less than the applied load?

When shells are meshed automatically by the program, a determination about the support for the edge nodes must be made. On the Shells tab of the spreadsheet, the fifth sheet is for "Intermediate Supports", and the first control is a check box labeled "Only at Ends"

If this box is unchecked (which is the default setting) then the program will extrapolate similar supports along the meshed edges of the shell. You can verify the support conditions for the meshed nodes using View - Finite Elements. In the example below, since all 4 corners has some restraint, all four edges are also restrained in 1 or more degrees of freedom.

If you plot or report the nodal reactions for such a wall, you need to report all of the nodes, not just the corner nodes to see the total reaction on the system.

If the option is checked, then only the original corner nodes are restrained, and only those points will have reactions.

 Press F1 on the "Intermediate Supports" spreadsheet to get more Help on the "Extent" option. 

See Also

RAM Elements Masonry Wall FAQ

Ram Elements - Meshing Errors [TN]

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!

Why do I get the warning Quality (shape ratio) on one or more segments of shell "#" is too low. There may be nodes that are too close on its edge?

Ram Elements can automatically mesh complex slabs into quadrilateral elements. In order to accommodate the various user specified node locations, the resulting mesh can become highly skewed and when the shape of the elements diverge far enough from square a warning will be given.

One common cause for the problem is to model a shell with an edge from point A to point C. Another node, B, falls nearly along the line between A and C but not quite. The program tries to include node B in the finite element mesh for the shell and it also tries to maintain the original edge from A-C. When B is far enough from the edge, then the program will mesh without warning. If node B is only a tiny fraction on an inch from line A-C, then the edge will just be adjusted to connect to point B, but when the node is off by more than the merge nodes tolerance, then the warning will occur and you can visualize the problematic mesh:

See Also

Ram Elements Shells FAQ

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!

When a member with a rigid offset includes an end release where is the hinge exactly?  

When a member is offset from its reference node, a rigid link is created between the original node which is unmodofied and the new member end position. The link is essentially a very stiff member with both ends fixed. If the member in Ram Elements is then hinged, the hinge occurs at the new end location of the member, before the rigid link.

Note, other Bentley Structural Analysis and Design products like STAAD.pro and RAM Structural System are similar in this regard.

See Also

RAM Instability in Finite Elements Analysis [TN]

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!

Problem Description

When RAM Elements is opened, it also retrieves a RAM Connection license. This behavior may not be desirable for the following reasons:

1. An engineer is not modeling connections within RAM Elements, causing unnecessary license usage.
2. Another engineer using RAM Connection Standalone requires access to the program at the same time.

Reason

By default, RAM Elements release 13.00.03.45 and earlier enables connection integration features within the program if the RAM Connection for RAM Elements component is installed. Starting with Ram Elements 13.02.00.99, which uses trust licensing, we changed the default behavior so that users have to opt-in to utilizing Ram Connection. If a RAM Connection license is available, the program will retrieve a license automatically and add buttons for Connections, Bolts, and Welds to the Databases ribbon. If the integration features are not needed, this behavior can be disabled.

Steps to Resolve

Option 1: Disable RAM Connection integration within RAM Elements.

If an engineer only occasionally models connection data within RAM Elements, the integration can be disabled from within RAM Elements itself and turned on only when needed.

1. Open the E menu in the upper left.
2. Click the General Configuration button in the lower right corner.
   
3. In the window that appears, click the Licenses tab.
4. Then clear the checkbox labeled "Check RAM Connection license" (or "Use a license in each session").
   
5. Click OK to save changes.

RAM Elements will disable the RAM Connection integration features and will no longer automatically retrieve a license or log usage for RAM Connection.

Ram Elements should then be restarted.

Option 2: Remove the RAM Connection for RAM Elements component.

For RAM Connection 8.0 only, the integration component, which is called RAM Connection for RAM Elements, is installed separately. If an engineer will never model connections within RAM Elements, uninstall the RAM Connection for RAM Elements component from the Add or Remove Programs (Windows XP) or Programs and Features (Windows Vista/7/8) control panel. RAM Elements will then retrieve a license only for itself regardless of the license setting in the Configuration dialog. Users of RAM Connection 7.3 and earlier should use Option 1 to disable integration.

See Also

[[RAM Connection is installed, but the Connection button fails to appear in RAM Elements]]

[[RAM Connection v9.0 and RAM Elements]]

[[SELECTsupport TechNotes and FAQs]]

Problem Description

After installing RAM Connection v9.0, the Connection toolbar and Conn tab in RAM Elements no longer appear.

Explanation

RAM Elements 13.00.03.47 and earlier does not support RAM Connection v9.0. RAM Connection for RAM Elements v8.0 must remain installed in order to use the connection module in those versions of RAM Elements. If RAM Elements for RAM Connection was uninstalled before installing RAM Connection v9.0, then the Connections toolbar and Conn tab will be removed.

Steps to Resolve

A. Install Ram Elements 13.02.00.99 or later.

B. The following steps can be used to restore Ram Connection 8 functionality with Ram Elements 13.00.03.47 or earlier.

If RAM Connection v9.0 has not been installed, make sure that RAM Connection for RAM Elements is not uninstalled prior to running the installation setup.

If RAM Connection v9.0 has been installed and RAM Connection for RAM Elements was uninstalled, open the Setup.exe file in C:\Bentley Downloads\rc08000023en. If this file is not found, download the installation for RAM Connection v08.00.00.23 from the SELECT download page. Click here for instructions on accessing the download page.

In the setup dialog, click the link labeled "Install RAM Connection for RAM Elements" as shown in the screen capture below to reinstall the component.

See Also

[[RAM Connection is installed, but the Connection button fails to appear in RAM Elements]]

Why does RAM Elements also retrieve a RAM Connection license?

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

Problem Description

After installing RAM Connection 8.0, the Connection button still fails to appear in the Database ribbon within RAM Elements. 

Ram Connection 9.0 is not compatible with Ram Elements version 13.00.03.45 or earlier.

It is compatible with Ram Elements 13.02.00.99 or later. See [[RAM Connection v9.0 and RAM Elements]]  for details.

Reason

Starting with RAM Connection 8.0, RAM Connection for RAM Elements is no longer installed automatically with RAM Connection Standalone.

Steps to Resolve

1. Open the RAM Connection installer by running Setup.exe in the following directory:
   C:\BentleyDownloads\rc08000023en
2. Click the link labeled "Install RAM Connection for RAM Elements" as shown in the screenshot below.

A valid license for Ram Connection (or Structural Enterprise) must be available when launching Ram Elements, otherwise the connection toolbars are still hidden.

Finally, go into Ram Elements - e menu - General Configuration - Licenses tab and make sure the box to "Check RAM Connection license” is checked. If it is not, check it and restart. This wiki explains why some users turn that option off intentionally.

See Also

[[Why does RAM Elements also retrieve a RAM Connection license?]]

[[RAM Connection v9.0 and Ram Elements]]

Unable to Satisfy All Prerequisites for RAM Connection Release 9.0

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!

Can I assign a section such as a HSS or channel to a beam?

Currently, only I-shaped (wide flange) sections can be assigned to beams in RAM Connection. It is not possible to assign other section types, like HSS or channels, to beam members, though they can be used as columns or braces in many connection templates.

What is the difference between Basic Connections and Smart Connections?

The RAM Connection Manual defines these connections as follows:

Basic Connection:  A connection template that can automatically adjust the geometry (position or dimensions) of the connection pieces to fit the connection members. It does not calculate the quantity or dimensions of the connecting pieces (bolts, plates, etc) to resist the applied forces.

Smart Connection: A connection template that can automatically calculate the quantity and dimensions of the connecting pieces (bolts, welds, plate sizes etc) to resist the applied forces.

When basic connections are designed, the program searches through a list of predefined connection templates and selects the first connection in the list that satisfies the design requirements.

When smart connections are designed, the program optimizes the connection parameters. See the RAM Connection Manual for a list of parameters that are optimized for each connection type. If a parameter is not optimized, the program uses a default value that be modified in the Connection Pad as needed.

Some complex connection templates like gusset pate or base plates only have a smart variety. 

Where are the abbreviations used for joint types and connections defined?

The abbreviations are defined in the RAM Connection Manual (available from the help ? or as a pdf from the Windows Start menu). The naming conventions for both joints and connections are listed in Chapter 2, The Connection Database - Database organization. Here is a list of the joint types from that section:

1. Beam – Column Flange (BCF)
2. Beam – Column Web (BCW)
3. Beam – Girder (BG)
4. Beam Splice (BS)
5. Column Splice (CS)
6. Continuous beam over column (CC)
7. Column, beams and braces (CBB)
8. Chevron braces (CVR)
9. Vertical X braces (VXB)
10. Column – Base (CB)
11. Column – Base – Braces (CB)

How can I change the design code (AISC 360 or BS 5950) or the design method (ASD or LRFD)?

RAM Connection Standalone:

1. Click on the Design menu tab at the top of the program window.
2. Find the Assignment toolbar.
3. Double click on the small square box with arrow pointing to the lower right corner to open the Customize Connection Design dialog.
4. Edit the design code (or design method in version 8).

Note, in Ram Connection Stand-alone version 9.0, changing the design code does NOT retroactively alter the assigned code for the existing joints in the file. This was done intentionally so that the user can have some joints designed to one code and other joints designed to another code within a single file. Consequently, if the design code for existing joints needs to be changed, the code should first be changed, then reassign connections to the joints.

RAM Connection for RAM Structural System:

1. Click on the Design menu tab at the top of the program window.
2. Find the Assignment toolbar.
3. Double click on the small square box with arrow pointing to the lower right corner to open the Customize Connection Design dialog.
4. Edit the design code (or design method).

RAM Connection for Elements:

The design code and design method is controlled by the code selected for design when performing a design in the RAM Elements model. To change the design code or design method, redesign the model and choose the desired design code.

Changing the design code will not automatically update generated load combinations. After changing the design method, delete and regenerate the load combinations.

When designing a base plate connection, the ACI 318 Appendix D checks are not completed.

Since the ACI Appendix D checks are based on ultimate limit state design, RAM Connection will only complete the ACI Appendix D checks if LRFD is selected for the design method. See frequently asked question above for information on changing the design method.

Information that is modified in the Connection Pad is not saved after clicking the Save button and exiting the dialog.

Any item that has an icon with a red arrow* to the left of it (see figure below) is defined in a dialog outside the Connection Pad. These parameters can be edited in the Connection Pad, but the information will be lost after closing the dialog. To change the parameters permanently, modify the values in the dialog where the information is initially defined. Edit the Joint to modify loads, section, materials, etc. Edit the seismic provision options in the Customize Connection design dialog.

 * In Ram Connection 9.0 this arrow is blue.

Can I design a Gusset Connection using a Pipe Column?

No, currently in Column-Beam-Brace joints (CBB) only Wide flange (W) and Square or Rectangular Tube (HSS-rect) shaped sections can be used for columns. Circular shapes can be used for braces and as columns in some joints, but not the gusset type. A change request for pipe columns in these joints has been logged.

Why is the controlling load condition as a single load case?

RAM Connection completes a design check for all load conditions, including individual load cases and load combinations. For some connection types, such as a base plate connection with wind uplift, the design for an individual load case may control the design. The single load cases can be removed from consideration as follows:

RAM Connection Standalone or Ram Connection for RAM Structural System :

1. Click on the Design menu tab at the top of the program window.
2. Find the Assignment toolbar.
3. Double click on the small square box with arrow pointing to the lower right corner to open the Customize Connection Design dialog.
4. To have only the load combinations considered click the button, "Select all load combinations", or manually check the desired conditions.

Please note that this will not permanently delete the load case results from the worksheet. See frequently asked question above for details.

RAM Connection for Elements:

1. Click on the Modules ribbon menu.
2. Double click on the small square box with arrow pointing to the lower right corner to open the Customize Connection Design dialog.
3. To have only the load combinations considered click the button, "Select all load combinations", or manually check the desired conditions.

I'm designing a connection with seismic provisions, but the Ry and Rt values don't look right, what's wrong?

Ry (Yield strength ratio) and Rt (Tensile strength ratio) are properties of the material in Ram Connection. The can be reviewed using Home - Databases - Materials - Edit.

To add your own materials with different values, refer to the wiki Creating custom elements in RAM Elements which also applies to Ram Connection.

Note, imported materials from RAM Structural System or STAAD.pro may not have the expected values for Ry and Rt since those are not directly supplied by either of those applications. For Ram Elements users with imported RAM SS files, edit the imported RAM SS materials as shown below (or reassign different steel material to the members):

For STAAD users, be careful to define the proper values when using the RAM Materials dialog box within the connection mode.

For further details refer to Tips for Using RAM Connection within STAAD.Pro [TN]. and How to Customize a RAM Connection Template in STAAD.Pro 

See Also

Troubleshooting Errors when Assigning Connections

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

Ram Connection Stand-alone crashes when opening existing files from the file browser or from the Welcome Screen, recent file thumbnails. It may crash right away or only when designing a connection within that file.

Solution

Install Ram Connection 9.02.00.117 or later. The information below applies to users with version 09.01.00.99 or earlier.

Work-around: turn off the option to "Show the Welcome Screen on Startup". Then close and restart the program and open the file using the upper left file open button instead.

The Welcome Screen can be reactivated using the link under the Help ?.

See Also

RAM Elements Design Crash

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

Hello, I have read that variable springs are used when vertical displacements occur in pipelines do to thermal expansion, what I do not understand is the function of the variable springs, because I have vertical displacements without the variable spring and by the time I add the supports the displacements, and the stress do to thermal expansion remains almost the same, as I show in the next report.

(Please visit the site to view this file)

Problem Description

In the V8i releases listed below, the User Name, which is shown in the header of program output, is based solely on the Windows login name.

• Microstran 09.20.01.18
• Limcon 03.63.01.11
• MsTower 06.20.01.08

In some situations, the user name may also include the suffix, "Not for Production Use"

Solution

An update release for all three applications is in progress and will have an option under File -> Configure -> General to override this and manually specify the desired User Name to show on the output.

build numbers with the solution; 

• Microstran 09.20.01.21
• Limcon 03.63.01.14
• MsTower 06.20.01.09

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs