Release Date: July 7, 2014
This document contains important information regarding changes to the RAM Structural System. It is important that all users are aware of these changes. Please distribute these release notes and make them available to all users of the RAM Structural System.
This version can be found on the Bentley SELECT Services Downloads and Updates web page at:
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.
Updated Star Seismic Buckling Restrained Brace Table and Values
The Star Seismic Buckling Restrained Brace table has been updated by Star Seismic, with an expanded library of low capacity brace options included. Additionally, design values for stiffness and overstrength factors determination have been updated.
Some program errors have been identified and corrected. 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.
LOAD COMBINATION GENERATOR: If one template's name was a subset of another template's name, the first template did not work correctly.
Effect: Could not use both templates.
EUROCODE UKNA STEEL COMBINATIONS: In the template RamSteelEuroUKNA.cmb the default for Reduction Factor Xi was set to 0.85 (which is the recommended value in EN 1990:2002), but it should be 0.925 (which is the required value in the UK NA).
Effect: Incorrect factors in some load combinations if the default value for Xi was used rather than the value of 0.925 specified in the UK National Annex.
CANTILEVER CAPACITY: For beams with cantilevers on both ends, the moment capacity listed in the Beam Design report was incorrect for the cantilever on the right end of the beam.
Effect: Report error only, the designs were correct.
BS 5950 HIGHER DUCTILITY SHEAR CONNECTORS*: Amendment 1 to BS 5950 allows the use of a lower minimum percent composite if the shear connectors qualify as "Higher ductility". In addition to other requirements, these only occur when the profiled deck is perpendicular to the beam; however the program erroneously allowed the lower percent if it met all of the other requirements for “Higher ductility” even if the deck was parallel or was a flat formed slab.
Effect: When the deck was parallel or flat slab the program specified too few studs if the minimum percent composite requirements controlled the design.
CAN/CSA S16-09 HIGH SHEAR: The moment capacity of beams was reduced when the beam had high shear.
Effect: Incorrectly reduced moment capacity when the beam was highly stressed in shear. That reduction of moment capacity due to high shear is not required and not applicable per the CAN/CSA S16-09 Specification.
CAN/CSA S16-09 TENSION FLANGE STRESS: When checking the tension flange stress per Clause 17.11 for unshored beams the program was using an allowable stress of 0.9Fy rather than Fy.
Effect: If that check controlled, a member size may have been selected by the program that was larger than necessary or an erroneous design warning may have been given.
USER-ASSIGNED BRACING: Adding a column or changing the story data would clear user-assigned bracing.
Effect: The program would use the bracing determined by the program rather than assigned by the user when determining the unbraced length of the column.
USER-ASSIGNED COLUMN SPLICES: Adding a column or changing the story data would clear user-assigned splice level assignments.
Effect: The program would use the splice levels specified in the Story data rather than those assigned to individual columns by the user when determining the splice locations of the column.
CAN S16-09 DESIGN REPORT: An incorrect minor axis unbraced column height was reported for columns unbraced in the minor axis.
Effect: Report error only, the designs were correct. The report showed an incorrect minor axis unbraced length.
CAN S16-09 U1 FACTOR: For columns subjected to compression and bending a U1 factor of 1.0 was always used.
Effect: Interaction equation values may have been incorrect (conservative). Columns that would have otherwise passed design checks may have been failed.
MULTI-SEGMENT COLUMN STACK*: For column stacks where the unbraced length in either the major or minor axis was comprised of two or more segments of columns (i.e., the unbraced column length extended two or more stories) and beams framed into the intermediate story that applied moments (such as stub cantilevers) but did not provide bracing, individual columns within the unbraced length may have been designed using an incorrect moment at the unbraced level.
Effect: For the unusual case described above the design moment used at the unbraced level may have been incorrect. This could have resulted in incorrect designs if this should have been the controlling design moment or if the resulting modification factor for nonuniform moments (Cb for AISC, w2 for CAN/CSA S16, mLT for BS 5950, C for Eurocode, and Moment Modification Factor for AS 4100) was incorrect. This error did not affect the design of columns braced at each story.
Note: For column segments in a multi-column stack between unbraced stories, and where intermediate stories have moments due to beam, cantilever or stub cantilever framing, a moment modification value (Cb, w2, mLT, etc.) of 1.0 is assumed. Where no intermediate framing exists between unbraced points, the design moments for the intermediate segments are interpolated from the moments at the top and bottom brace points of the multi-segmented column stack. At intermediate stories where moments due to beams, cantilever and stub cantilevers exist, the design moment assumed is the moment due to the beam, cantilever or stub cantilever.
RAM Frame – Analysis
HANGING DIAPHRAGMS NOT RECOGNIZED AS PSEUDO-FLEXIBLE*: If a model included a hanging diaphragm (a level that is only supported by hanging columns), the Pseudo-Flexible Diagram Properties dialog did not show it and hence, it was not recognized as a pseudo-flexible diagram.
Effect: Such diaphragms were not recognized as pseudo-flexible diagrams.
DIAPHRAGM MASS DIALOG: If a model had a story with no diaphragm but had some mass on members, (referred to as “None” in the dialog), and if the user tried to combine this mass to another diaphragm, the program ignored it and reverted back to the original state (not combined).
Effect: Combining "None" mass components on such stories was ignored. Note that if there was a diaphragm at that level the Combine command functioned correctly.
DROP CAP ON RAISED OR LOWERED COLUMNS: When a drop cap was located on a column that had been raised or lowered, the slab mesh generated by the program was incorrect.
Effect: Invalid analytical mesh generated.
Note: The user should also be aware that if a drop cap falls on more than one slab polygon with different slopes, the drop cap must be modeled in smaller sections such that there is a different section on each different sloped slab polygon.
COREBRACE TABLE: The CoreBraceAISC.TAB table had not been updated when the other AISC tables were updated with some new sizes.
Effect: The CoreBraceAISC.TAB table was not compatible with the Beam and Column design tables and wouldn't allow the modules to run with that table selected.
RAM Frame – Steel Standard Provisions
EUROCODE STEEL COMBINATIONS: In the templates used to generate the steel combinations for the Eurocode and for the Eurocode UK National Annex (RamSteelEURO.cmb and RamSteelEuroUKNA.cmb) the Reduction Factor Xi was applied to the GammaGj,inf * Gkj,inf term. It should only be applied to the GammaGj,sup * Gkj,sup term.
Effect: Incorrect (conservative) load factor on the Dead Load for the Eq. 6.10b combinations when the Permanent Action is Favourable.
EUROCODE STEEL COMBINATIONS* In combinations that include Negative (that is, upward acting, usually caused by uplift on the backspan support of a cantilever beam) Roof, Negative Live, and Wind, the Psi0 term for Imposed loads, rather than for Roof loads, was applied to the Negative Roof term. Same for those that include Negative Roof, Negative Snow, and Wind.
Result: For a rare condition of uplift, potentially some incorrect Load Combinations. Note that those Psi0 terms usually have the same value, in which case there wouldn't be any error.
CAN S16-09 TENSION CAPACITY: The Code Check report did not show the capacity for a member design governed by tensile and bending loads.
Effect: Although the member code check was correct, the report failed to show the tensile capacity of the member if controlled by tensile and bending loads.
RAM Frame – Steel Seismic Provisions
DYNAMIC STORY SHEARS* : In the calculation of story shear demands for the joint checks for AISC 341-10 LRFD + AISC 358-10, the program did not consider story shears for Response Spectra load cases (only gravity, wind and seismic load cases were included).
Effect: Calculated story shear demands for joint check calculations did not include any dynamic load case result.
AISC 341-10 CUSTOM COMBINATIONS: Member Code Checks under the AISC 341-10 crashed when custom load combinations were created.
Effect: Member code checks using the AISC 341-10 code could not be performed when custom load combinations were included.
RAM Concrete – Analysis
DROP CAP ON RAISED OR LOWERED COLUMNS*: When a drop cap was located on a column that had been raised or lowered, the slab mesh generated by the program was incorrect.
TRANSFER WALL SUPPORT*: If a wall was supported by a slab (not by a wall, column or beam below) and there happened to be a mat foundation at the ground level that encompassed the wall coordinates, wall forces were not transferred to the supporting slab or below.
Effect: For the condition described, wall forces were not transferred to the supporting slab and hence to the supporting members, which may have then been underdesigned.
RAM Concrete – Beam
CHINESE CODE DESIGN STATUS*: Changing criteria did not reset design status when the design code was GB 50010.
Effect: Data in Criteria dialogs may not have matched the criteria used in design. The error was corrected if the model was subsequently redesigned.
RAM Concrete – Column
COLUMN SHEARS*: When designing to ACI 318-11, column shear forces due to earthquake loading were factored by the older 2.0 factor instead of the new 3.0 factor specified in Section 188.8.131.52(b).
Effect: Incorrect column shear may have been used in design.
ACI SMF JOINT CHECK: A phi value of 0.75 was being used instead of the value of 0.85 according to ACI 318 Section 9.3.4(c).
Effect: Conservative value of shear used in the joint checks.
RAM Concrete – Shear Wall
BOUNDARY ZONE*: The boundary zone check per ACI 318 Section 184.108.40.206 may have yielded incorrect results when reinforcement zones were designated as "Not boundary, but check".
Effect: This could have resulted in sections cuts passing when they should have not, or sections cuts failing when they should have passed.
TAKEOFF: On the Takeoff Report, reinforcement takeoff data was not discretized correctly by bar size when one or more wall panels had manually assigned reinforcement. In addition, the calculated weight of steel was underestimated by around 10%.
Effect: Report error only. Reinforcement takeoff values were incorrect.
Note: In order to prevent the error on the report from persisting, it is necessary that the user-specified reinforcement be cleared (Process – Clear Reinforcing) and then reassigned.
SPREAD FOOTING VIEW/UPDATE: The View/Update dialog did not recognize the top bars in a design unless there were bars in both the length and width direction. In this case, the "Top Reinf." button was grayed out. If the "Optimize Reinforcement" check box was unchecked to freeze the reinforcement, the top bars were cleared out. This resulted in subsequent Redesigns to fail.
Effect: User-specified spread footing designs that only had top bars in one direction could not be updated and saved in the database.
ISM / Structural Synchronizer
Note: The ISM errors listed here only affected the ISM repository; the designs in the design modules were correct.
BEAM REINFORCEMENT ON 64BIT INSTALLATION: With 64bit installations, the concrete beam reinforcement would not export to a repository.
Effect: No beam reinforcement was included in the repository.
CONCRETE COLUMN REINFORCEMENT: For non-symmetric bar patterns, the bars along the long side and short side were reversed upon export to ISM.
Effect: Column reinforcing was incorrect in the ISM repository.
CONCRETE COLUMN TIES: When a column had additional interior ties, the interior ties were exported to ISM slightly inset from the outside tie, so the inner ties intersected the longitudinal bars they were intended to confine.
Effect: Dimensions of the interior ties was incorrect, resulting in the ties clashing with the column reinforcement in the ISM repository.
COUPLING BEAM TIES: Coupling beam tie bars would not be fully spaced along the coupling beam when model was in metric units.
Effect: Only a portion of the coupling beam ties were included in the ISM repository.
RECTANGULAR SPREAD FOOTING REINFORCEMENT: For rectangular spread footings, the bars exported to ISM would not fit within the footing in the long direction.
Effect: The dimensions on the longitudinal bars were incorrect, resulting in the bars extending past the ends of the footings in the ISM repository.