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Release Date: July 6, 2011
This document contains important information regarding changes to the RAM Structural System. It is important that all users are aware of these changes. Please distribute these release notes and make them available to all users of the RAM Structural System.
RAM Structural System V8i is part of the Bentley Systems V8i family of products. It is part of a coordinated release of the entire suite of Bentley programs. Its intent is to create a common identity between all of the Bentley programs, indicating the growing integration between these programs. V8i is not a reference to a version number; this is Release 14.03, or Version 14.03, of the RAM Structural System.
The Tutorial Manual has not been updated but is still valid. The appearance of some parts of the program in this version may differ from that shown in the Tutorial.
Version 14.04 automatically converts databases created in previous versions to the new database format. Note that a backup file is created automatically when a database is converted; the name of the database is the same, with “Orig” and the version number appended to the name. The file has an extension of “.zip” and is located in the same directory as the original database.
Version 14.04 may give slightly different results than V14.03.
The previous steel tables and load combination templates supplied with the program will be replaced with new tables and templates of the same name. If you have customized any Master or Design tables or load combination templates supplied with the program without changing the file names, those file names should be renamed from the original RAM table names prior to installation to prevent your changes from being lost.
This version can only be installed by downloading the installation file from the Bentley SELECT web site. It can be found on the Bentley SELECT Services Downloads and Updates web page at:http://selectservices.bentley.com/en-US/Support/Downloads+And+Updates/
Select “Search Downloads” and log in using your User Name and Password. Perform a Search by searching for the “RAM Products”, and select the latest version of the RAM Structural System. See Appendix A at the end of these Notes for information on Installation Directories.
For details on these new features and enhancements, refer to the manual .pdf files available from the Help menu in each module or from the Manuals folder on your hard drive.
Like standard columns, hanging columns can be sloped.
Models can now be imported to and exported from ISM repositories, providing interoperability with other Bentley and third-party programs.
The Change Management system provided with ISM identifies changes made to the model, allowing for the changes to be accepted or rejected before re-importing a model.
This feature also provides another method of exchanging models between the RAM Structural System and Revit.
The design and analysis requirements of AISC 360-10 Specification for Structural Steel Buildings, including the Direct Analysis Method, have been implemented. These requirements are very nearly identical to the requirements of the previous AISC 360-05, although there are some differences. The option is given to select ASD or LRFD for either version of AISC 360. Most designs will not be affected by selecting the new Specification versus the previous Specification.
The pertinent requirements of IBC 2009, based on ASCE 7-05, for Live Load Reduction, Wind Loads, Seismic Loads, Response Spectra and Load Combinations have been implemented. Because both IBC 2006 and IBC 2009 are based on ASCE 7-05 there is no difference between the two, except that Supplement No. 2 which revises Eq. 12.8-5 is mandatory for IBC 2009. In the generation of Seismic forces in the Loads – Load Cases command in RAM Frame the option to apply this requirement must be selected if the loads are to comply with IBC 2009.
When selecting BS 5950:2000 as the design code in the RAM Steel Beam module an option is given to apply the Amendment 1:2010 requirements. This has an impact on composite beam design, especially the capacity of shear connectors and the minimum percent composite.
EurocodeThe implementation of the Eurocode has been expanded:• EC 2 in RAM Concrete Shear Wall module.• EC 3 Baseplate design in RAM Steel Column module.• EC 3 Joint Checks in RAM Frame Steel Standard Provisions module.
Live Load Reduction for Walls• The Live Load Reduction requirements of all of the building codes implemented in the program are now available for Walls under one-way decks. The Live Load Reduction percentages are automatically calculated and applied to the Live Loads.• In lieu of the automatically calculated reduction percentages, user-specified reduction percentages can be assigned to walls supporting either one-way or two-way deck.
Computational Robustness and TolerancesThe library of polygon and math routines was significantly improved to make the analyses performed in several parts of the program more robust and more accommodating of members modeled imperfectly; the program can accommodate larger tolerances in coordinates. These changes are particularly beneficial for models created by importing models from Revit or DXF. Errors that sometimes occurred when slab edges were assigned directly on beams (rather than at an offset) have been significantly eliminated. These changes will result in a significant reduction in the incidences of polygon intersection and tolerance error messages, allowing the program to perform the various analyses in a more robust way, for models that previously would have terminated the analysis.
ModelerSeveral enhancements and modifications were made in the Modeler to improve the interface. Key enhancements include:• There are now options to show columns to scale in Modeler, in the Options – User Interface command. If these options are not selected the columns will be drawn a fixed, slightly exaggerated size.• Concrete columns with a circular concrete section property assigned as their size are now drawn as round in Modeler.• The dialog boxes for Steel Column commands that include specifying column orientation now show the orientation options with icons of the currently selected shape (previously it only showed an icon of an I-shape even if the selected shape was something else).• Steel columns using Round Hollow Sections and Rectangular Hollow Sections are now drawn hollow in the 3D graphics (previously they were drawn with solid end caps), making them more distinguishable from concrete columns.• The Layout – Type – Copy command has been enhanced to allow Walls and Beams to be copied independently. Previously either both were copied or neither were copied, now one or the other or both can be specified in the Select Items list.• In the Layout – Slab – Deck Assign – Show command and the Layout – Loads – Surface – Show command the Gross and Net areas of the polygon are listed. The Gross area is the area of the entire polygon; the Net area is the area of the clipped polygon, excluding openings and any area covered by a different polygon.• The View – Measure Distance command was enhanced to show distances to more decimal places.
Steel Beam Interaction ColorsBeams can be displayed in colors based on the demand-to-capacity ratios for strength, deflection, and the controlling value of the two. The value of the ratios can be displayed. This is done using the Process – Design Colors command.
Star Seismic Buckling Restrained BracesIn RAM Frame, the implementation of Star Seismic Buckling Restrained Braces (BRB) has been significantly enhanced. They are now recognized as a distinct shape in the Assign – Braces – Size command, and can be assigned, analyzed and designed. Criteria for Star Seismic BRB’s can be set using the Criteria – Buckling Restrained – Star Seismic command which is used globally for those braces, or can be assigned to individual braces using the Assign – Braces – Buckling Restrained – Star Seismic command. The Axial Stiffness Modifier is automatically calculated, but can be over-ridden by the user if desired. The braces are checked per the requirements of the AISC 360 Specifications and the AISC 341 Seismic Provisions.
See Appendix A of this document for more details.
The ability to analyze and design generic BRB’s that was previously available is still available.
Note: Because this more complete implementation of Star Seismic Buckling Restrained Braces uses a specialized table, the master table named BRB_StarAISC.TAB that was installed with V14.03 can be deleted from the Tables directory.
RAM Frame License Consolidation• The RAM Frame Drift module is now available as a part of RAM Frame, and no longer requires a separate license. This module is now available for all users of RAM Frame by selecting the Mode – Drift Control command. The Drift module provides a power means of identifying which elements in the model contribute the most to the lateral drift of the structure, allowing sizes to be more economically optimized to control the lateral drift. See the RAM Frame Drift Control manual for information on this feature.• The RAM Frame Steel Standard Provisions module and the Seismic Provisions module are licensed together under a single license, as the RAM Frame Steel module. Users with a license for the Steel Standard Provisions now also have access to the Steel Seismic Provisions.
RAM Frame:Several enhancements have been made to RAM Frame.• Frame Beam Connection Type: Standard and special connection types can be assigned to beams for the beam-to-column connection using the Assign – Beams – Connection command in RAM Frame. These include: o The standard Fixed or Pinned condition.o Springs defining the Major Axis rotational stiffness. This can be a specific spring stiffness value or a percent of the beam stiffness.o Custom connections defined as a length and stiffness modifiers. This is useful for the analysis of beams using proprietary connections or for haunched beams. The beam design is based on the member forces out at the distance (length of connection) specified.o Reduced Beam Section (RBS). The option is now given to explicitly include the effects of the reduced properties in the analysis of the frames. As was done in previous versions, the frame is checked per the requirements of AISC 360 Specifications and AISC 341 Seismic Provisions for an RBS.o SidePlate. The proprietary SidePlate connection can be specified. The stiffening effects of the side plates are automatically determined and included in the analysis. The beam and column design is based on the moments at the faces of the plates, the frame is checked per the requirements of AISC 360 Specifications and AISC 341 Seismic Provisions. See Appendix B of this document for more details.The impact on the building periods, drifts and member force distribution due to these connection types is included in the analysis. The ability to design RBS’s was incorporated previously; now the program can consider the impact of the reduced section on the building drifts.• Gravity Loads: In order to more correctly determine the gravity loads on Lateral Frame members in concrete structures with two-way slabs, an option to include the gravity framing in the gravity load case analysis is now available in the Criteria – Diaphragm command. Previously the gravity members where represented by springs; that option is still available but including all of the gravity framing members in the analysis of the gravity load cases may often be more accurate. One option or the other, to include gravity members or to represent the gravity members as springs, must now be selected.• Cracked Factor for Walls: There are now two cracked factors that can be designated for walls, one for the in-plane stiffness and one for the out-of-plane stiffness. Also, the method of applying the cracked factors has been improved, applying them to the stiffness rather than to the thickness used in calculating the stiffness (which over-estimated the effects of cracking on the out-of-plane stiffness).• Nodal Mass in Z-direction: An option has been added to the Criteria – General command to include the nodal mass in the Z-direction in dynamic analyses. This option is available when the diaphragm is specified as Semirigid. Except for buildings with large cantilevering areas this option is generally not necessary.• Large Models: Improvements in the solver result in faster analysis of large models.• Reactions: The Process – Results – Reactions command has been enhanced to include the ability to graphically show the reactions under walls for the Response Spectra load cases.• ASCE 7-05 Stability Coefficients report: The calculation of the stability coefficient given in this report has been enhanced to include Live Load in the Vertical Load.• Centers of Rigidity report: A new, more accurate methodology for the calculation of center of rigidity has been implemented for this report.• Gravity Loads on Two-way Decks report: A Summary of Total Gravity Loads has been added to this report.
RAM Concrete:• Concrete Beam Reinforcing Elevations: An option to create DXF drawings with Detailed Elevations of the concrete beam reinforcing has been added to the Post-Processing – DXF File – Floor Framing command in RAM Manager. These can be created as an alternative to the Schedules previously available.• Copy Wall Reinforcement: In the Concrete Shear Wall module a Process – Copy Reinforcing command has been added to copy wall reinforcement from one wall or panel to another.• The Concrete Shear Wall module now allows as many as six layers of reinforcing to be considered in walls. Previously the limit was three. This option is found in the Assign – Manual Reinforcement command.
Error Corrections:Some program errors have been identified in V14.03.x and corrected for Version 14.04. Corrections made to graphics, reports, Modeler functions, program crashes, etc that were considered minor are not listed here. The noteworthy error corrections are listed here in order to notify you that they have been corrected or to assist you in determining the impact of those errors on previous designs. These errors were generally obscure and uncommon, affecting only a very small percentage of models, or had no impact on the results. The errors, when they occurred, were generally quite obvious. However, if there is any question, it may be advisable to reanalyze previous models to determine the impact, if any. In each case the error only occurred for the precise conditions indicated. Those errors that may have resulted in un-conservative designs are shown with an asterisk. We apologize for any inconvenience this may cause.
TablesDOUBLE ANGLE LABELS: When the program creates double angle labels it put '2' in front of the single angle label. This was incorrect for any angle sizes that start with a number (such as Australian angle 90x90x6EA). Effect: This did not impact the design of double angle sizes but the size shown was misleading or meaningless. In such cases the program now appends ‘2-‘ in front of the single angle label. Note: Double angle brace sizes assigned using the Australian or British tables need to be reassigned so that the correct labels will be used.
RAMAISC2.COL: The RAMAISC2.col table had bad data for the HSS7x2 Trial Group.Effect: The program would crash when it tried to read the table.
RAMARCELOR.TAB TABLE: The round bar information in the ramarcelor.tab table had an extraneous character.Effect: Round bars couldn't be used when ramarcelor.tab was selected as the Master table.
DXFBASE PLAN FONTS: The Font Styles selected in the "Text Options" dialog for the Base Plan were not rendered correctly in the output DXF.
ManagerModel Notes: Editing the Model Notes was not considered a model change and would not cause the program to ask the user if they wanted to save the model when exiting.Effect: Changes to Notes would be discarded if the model was not saved.
Framing TablesIBC ALTERNATE, UBC, SBC AND MASSACHUSETTS LIVE LOAD REDUCTION: The live load reduction calculated by these codes may have been incorrect (conservative) when R2 = 23.1*(1+ D/L) controlled because the deck self-weight was not included in the dead load value, D.Effect: The program may have resulted in over-conservative beam design where the R2 = 23.1*(1+D/L) formula controlled
ROOF POINT LOAD: When the option to Consider Snow, Ignore Roof was selected, point loads whose Live Load has been specified as Roof were included with the snow loads. This affected beam, wall and column loads.Effect: Roof point loads may have been applied even when the option to ignore Roof loads was selected. This may have resulted in over-conservative design.
WALL/BEAM POINT LOADS*: In some cases a beam or wall would incorrectly show a very large uplift point load. This was an extremely rare occurrence and would only happen if a point load was within a very small tolerance of (but not on) where another beam framed into that member.Effect: A very large uplift load would be applied to the beam or wall. The error was obvious when it occurred.
POINT LOADS*: If a point load was placed on a slab edge directly in line with a cantilever beam, but not the cantilever, the load was not distributed back to the cantilever. The load was lost. Effect: The load that should have been distributed to the cantilever end was not included in the cantilever beam design. The error did not occur if the point load was placed on the cantilever end, only if the load was placed on the slab edge beyond the cantilever beam end.
RAM Steel BeamWEB OPENING*: AISC Design Guide 2 Section 3.7a2 prescribes limits on an opening parameter, Po, to prevent web buckling. The limit for composite sections was applied to composite beams even if the beam was unshored. For the precomposite state the more stringent limit for steel sections should have been applied.Effect: Precomposite unshored beam was not held to the stricter requirement.
CANADIAN TENSION FLANGE STRESS*: The results shown for Tension Flange Stress when the design code selected was CAN/CSA S16-01 were incorrect.Effect: Beam designs not controlled by tension flange stress did not change, however designs may have been unconservative for beams controlled by tension flange stress.
TAPERED BEAM SNOW LOAD*: Snow loads tapering to zero were reported as a very small negative load in the +LL column of the beam loads report. The View Diagrams command in the View Update dialog box showed incorrect shear and moment diagrams for beams with snow loads tapering to zero.Effect: The controlling moment in the beam report and the shear and moment diagrams for beams with snow loads tapering to zero were inaccurate. The error did not occur if the smallest drift load magnitude was not 0.0.
REACTION SUMMARY: For SMARTBEAM and Westok Cellular beams, the beam unfactored reactions were listed in the Reaction Summary report even if factored reactions were specified to be reported.Effect: Although beam designs were correct, the factored reactions in the reactions summary report were not listed correctly for Smartbeams and Westok Cellular beams.
SMARTBEAM DETAILED REPORT: The web post results in the Detailed Report were not reported for Cellular SMARTBEAM when the cell diameter was optimized and the sized was assigned by the user. Effect: Although the beam designs were correct and the regular report showed the results of the web post check, the Detailed Report did not show the results for the web post check.
RAM Steel ColumnCANADA WWF COLUMNS: For the requirements of CAN/CSA S16-01 Clause 13.3.1, n was set equal to 1.0 for WWF and built-up column shapes even if in Group 1, 2 or 3, and even if built from Flame Cut plates.Effect: Conservative design of WWF and built-up columns.
RAM Frame – AnalysisMERGED LOAD CASE WITH NBCC2005 WIND AND SEISMIC*: When the user merged a nodal load case with a generated NBC of Canada wind or seismic load case the program ignored the generated wind or seismic loads and applied only the nodal loads for the merged load case.Effect: Wind or seismic components of a merged load case were not applied; only the nodal load components were applied. This only occurred for merged load case with NBC of Canada 2005 wind and seismic.
LOADS ON LATERAL WALLS SUPPORTED BY LATERAL COLUMNS BELOW*: If a lateral wall was supported by a stack of lateral columns under the wall, and if there was a point load on the lateral wall, the point was mishandled in such a way that it was applied to the columns in reversed direction.
Effect: Gravity loads on frame columns were incorrect, having been repeatedly reduced by the magnitude of the point load on the wall. This error only occurred in frame columns supporting a wall.
LOADS AND APPLIED FORCES REPORT: For models with semirigid diaphragms, if calculated nodal loads (seismic or wind) were smaller than 0.001 kips, the report excluded these point loads so that the values reported for applied loads on semirigid diaphragms and the calculated story loads did not match.Effect: This was only a report error. All loads were correctly applied on the diaphragms.
LOAD AND APPLIED FORCES REPORT FOR ASCE 7-05 SEISMIC LOAD CASE: The report has a section that gives values of Ta, Cu, T, Csmin, Csmax and k for each direction. The section's header indicates what governing equations used for calculating Csmin and Csmax. The section header was always printed according to the X-direction results. However, it was possible that different governing equations might be used for each direction.Effects: Section header may not have shown the correct equation number if X-direction and Y-direction were governed by different equations. This was only a report error, the correct forces were listed and applied.
STORY DISPLACEMENTS FOR SEMIRIGID DIAPHRAGMS: The Story Displacement report listed story displacement at mass center for semirigid diaphragms. If the mass center was in an opening or outside the diaphragm, the program either reported zero or garbage values. The program now reports an average value calculated from nodes on the diaphragm.Effects: This was a report error. No analysis results were affected.
GRAVITY COLUMN AND WALL SPRINGS FOR SLOPED DIAPHRAGMS: If a diaphragm was sloped, and if gravity springs were requested to be included in analysis of a model with a semirigid diaphragm, the program failed to create such springs.Effects: Gravity column and wall springs were not created in analysis. Hence, the analysis was performed without these springs.
MASS OF MEMBERS LOCATED INSIDE AN OPENING IN A SEMIRIGID DIAPHRAGM*: If a wall, column or beam was located inside an opening in a semirigid diaphragm, and if there were any mass line or point loads on these members (including member self-mass), the program ignored these mass loads. Effect: Mass on members was ignored if these members were located inside an opening in a semirigid diaphragm. This may have impacted the values calculated for the building periods.
RAM Frame – Steel Standard ProvisionsDOUBLE ANGLE CONNECTOR SPACING* : For double angle braces with user-assigned K-factors, the Member Code Check ignored the K-factor in the calculation of the Maximum Connector Spacing. Effect: The reported Maximum Connector Spacing may have been unconservative. When user-assigned unbraced lengths rather than K-factors were specified, the program correctly calculated the Maximum Connector Spacing. The other double angle design checks were not affected by this error, and were correct.
AISC 360 VALIDATION REPORT*: In some cases the Validation Report indicated that B1 factors do not need to be applied. This message was erroneous, that section of the report has been removed.Effect: Incorrect message.
ASD LOAD COMBINATIONS: There were some errors in the factors used on the Notional Loads in the load combination templates for AISC 360-05 ASD and IBC 2006 ASD. In some of the wind load combinations a factor of 1.0 was used on the Notional Live Load even though the factor of 0.75 used for the Live Load could have been used on the Notional Live Load as well. Also, in some of the earthquake load combinations an incorrect factor was used on the 0.2SDS term of the Notional Dead Load.Effect: Conservative factors used on Notional Loads. Not that this error only occurred if the Notional Loads were included with all combinations, not just the gravity load combinations. Note that it is almost always permissible by the Specification to include the Notional Loads with only the gravity load combinations; it is generally not necessary to include notional loads with the wind and seismic load combinations.
RAM Frame – DriftPARTICIPATION FACTORS FOR CONCRETE MEMBERS: In the Drift module, the program showed garbage numbers for concrete members. Effect: Calculated participation values for concrete members were invalid in Drift module. For steel members, they were correct.
RAM Concrete – AnalysisPIN BASE OF TRANSFER GRAVITY CONCRETE COLUMN*: If a user selected the option to pin the base of transfer concrete columns, the beam bending forces on the transfer beam were incorrect because program was incorrectly constraining the top rigid end node of the column with the diaphragm resulting in the column rigid end zone taking all of the moment.
Effect: Incorrect moments of transfer girders when the base of the transfer column was pinned.
WALL SELF-WEIGHT*: The wall self-weight did not exclude the opening self-weight in concrete analysis. Effect: Incorrect wall self-weight for walls with openings; this error was only unconservative if it impacted members or footings in uplift.
RAM Concrete – BeamCHINESE REINFORCING BAR SELELCTION: Regarding the Main Bar table used for the concrete beam design when GB50010 (Chinese) code is used: The selections of which specific bars to consider were not properly retained by the program after closing the dialog.Effect: If not considering all bars sizes when designing beams, the design would consider sizes the user had not selected.
RAM Concrete – Shear WallVERTICAL REINFORCING*: Vertical reinforcing in walls was offset from the start and end edges of wall panels by a distance Cc + 0.50" + Dvb/2, where Cc is the clear cover and Dvb is the diameter of the vertical bar. The 0.50" value should have been the actual diameter of the horizontal bar, not a fixed value of 0.50”.Effect: Very small change in the calculated flexural strength of horizontal sections in cases where the horizontal bar size is not 1/2" in diameter.
COUPLING BEAM DESIGN TO ACI 318: Section 188.8.131.52 of ACI 318-05 was getting checked even if the frame type was set to ordinary concrete wall. It should be getting checked only if it is a special concrete wall.Effect: Design failures may have been reported that did not actually apply.
SHEAR WALL REINFORCING SPACING LIMITS: The value of Lw used by the Concrete Shearwall Design module in calculating the spacing limits of ACI 318-08, 184.108.40.206, was smaller than actual in some instances, resulting in false error messages.Effect: Inapplicable design failures were displayed for section.
DataAccess (Note: these errors do not impact the RAM Structural System, they only impact client-written and third-party software written using these functions.)DATA ACCESS - GETMEMBERFORCES: The status of the forces was not checked before they were returned. If the analysis was not current, garbage was returned.Effect - Garbage numbers could be returned in place of actual forces when accessing forces through DA for models whose analysis was not current.