New Features and Enhancements
Tilt-up Building Analysis and Design
Powerful new capabilities have been implemented for the analysis and design of tilt-up buildings. In the Modeler walls are designated as either cast-in-place or tilt-up. Wall faces are designated as either interior or exterior exposure, and the appropriate bar cover is applied in design. If there are gaps between wall panels, that condition can be assigned (without the necessity of physically modeling a small gap between panels). Wall pressure loads perpendicular to the walls are defined and applied perpendicular to the walls. In RAM Frame, moments from beams framing into the wall and from deck supported by the wall are automatically determined and applied. A 2nd-order analysis is performed, accounting for the thin wall effects. In the RAM Concrete Wall module (previously called RAM Concrete Shear Wall) walls with reveals are designated, and the wall design section properties are reduced accordingly. The tilt-up walls are designed for both the in-plane forces (acting as shear walls) as well as for the out-of-plane forces. Steel beams, steel joists, and steel columns can be designed in RAM Steel. This new feature provides the engineer with tools to quickly and productively design tilt-up buildings safely and economically.
Eurocode Design of Steel Beams with Web Openings
The design of steel beams with web openings has been implemented for the Eurocode, based on the recommendations of SCI Publication P355 Design of Composite Beams with Large Web Openings. Round and rectangular openings are allowed. The need for web reinforcement is investigated, and if needed is designed by the program.
Eurocode Combinations in RAM Steel Beam
Previously the load combinations used for design per the Eurocode used the provisions of Equation 6.10 in BS EN 1990:2002+A1:2005. The program has been enhanced to now use load combinations based on Equations 6.10a and 6.10b. Designs based on the load combinations of Equation 6.10 were conservative, designs based on Equations 6.10a and 6.10b will likely result in more economical designs.
Web Opening Modeling
RAM Steel Beam has the ability to design for round and rectangular openings in steel beam webs. Previously the modeling of the openings in the Modeler required the definition and placement of each opening individually, one at a time. The Layout – Beams – Web Openings – Add command has been enhanced to allow generation of openings along a portion of the beam length or along the entire length. Placement of single or generated openings can be done on an individual beam using the Single command, or on a series of adjacent beams using the Intersect Line command. This is done by drawing a line across all of the beams for which the opening or openings are to be placed; all of the beams that intersect this line will have the openings added. Note that if the Intersect Line is drawn nearest to the left end of the beam the distance to the first opening will be measured from the left end; if the Intersect Line is drawn nearest to the right end of the beam the distance to the first opening will be measured from the right end.
Web Opening View/Update
In RAM Steel Beam module, when a beam has web openings the View/Update dialog has been enhanced to graphically show the beam with its openings. Failing openings are shown in red. If an opening is selected from the list of openings, the corresponding opening in the graphic will highlight; if an opening is selected in the graphic, the corresponding opening in the list of openings will highlight.
Previously openings could be modified in the View/Update command; now openings can also be added and deleted there.
Data Extractor
Model data can be easily extracted from the model using the Data Extractor. This can be accessed using the Post-Processing – Extract Data command in the RAM Manager. This feature has been available in a limited scope as a Technology Preview (beta) feature. It is now fully available for use. Available data is model geometry, Criteria selections, gravity steel beam and column results, and frame analysis results (frame displacements, reactions, forces, etc.). Templates can be created for reuse which specify precisely what information is to be extracted and included in the file. The data can be previewed in Excel format, and saved in any of several formats: Excel, Access, SQLite, or XML file formats. This provides a powerful tool for extracting data for use in in-house spreadsheets and programs. In order for the Frame analysis results to be available, select the option in the Process – Analyze command in RAM Frame to write the results to the Data Extractor database. See the RAM Manager manual for more information.
Installation Report.
An Installation Report is available in the Post-Processing menu in RAM Manager. This report lists the currently installed program version, the location of the ramis.ini file, and the locations of the various directories (Prog, Data, Tables, etc.).
Deflection Limits Listed on Steel Beam Design Report.
The Gravity Beam Design report lists the deflections and span/deflection ratios for the various conditions of Dead, Live, and total loads. This listing has been enhanced to now show the corresponding deflection limits specified by the user. The ratio of actual to allowable deflection values is also listed. This makes it easier to see to what limits the beam was designed.
ASCE 7-16 Seismic Forces Site Options
The implementation of the ASCE 7-16 Equivalent Static Force load case generator has been enhanced. The options for Site Class now make a distinction between Site Class B Rock and Site Class B Rock, Not Measured. This has been done in order to satisfy Section 11.4.3 which requires that if investigation indicates that the site is rock consistent with Site Class B, but site-specific velocity measurements were not made, Fa and Fv must be taken as 1.0. Previously the program assumed that site-specific measurements were made, so it did not impose the 1.0 limit on Fa and Fv. Also, the options for Site Class now make a distinction between Site Class D Stiff Soil and Site Class D Stiff Soil Default. Section 11.4.3 allows the site to be specified as Site Class D by default (unless required or determined otherwise to be Site Class E or F), where the soil properties are not sufficiently known; however, when Site Class D is specified by default, Section 11.4.4 requires that Fa not be less than 1.2. Previously there was no option to impose this limit on Fa.
An option has been added to either calculate SDS and SD1 based on the Site Class and the values specified for Ss and S1 or to use values of SDS and SD1 specified directly by the user. This is convenient when those values are given in the geotechnical report.
There is a new option to indicate that for SDS and SD1, the values are from a ground motion hazard analysis. This option is only available when the Site Class is D and the user has selected the option for the program to use specified values of SDS and SD1. Previously it was conservatively assumed that the values were not taken from a ground motion hazard analysis, which meant that for Section 11.4.8, Exception 2 was applied. This resulted in large applied forces, particularly because of the 1.5 factor that was required. If that option is selected it is not necessary to apply the requirements of Exception 2.
Mass Accidental Eccentricity
In the Loads – Masses command in RAM Frame, the % Eccentricity to be used in the calculation of the accidental torsion can be specified. Normally this value is 5% for IBC and 10% for NBC of Canada, for example. However, in some cases of torsional irregularity that value needs to be amplified. Previously only whole numbers could be specified, and the same value was used in both the X- and Y-Axis. Now decimal values can be entered, and values are entered separately for the X- and Y-Axis.
Wall Self-Weight
There are now options to specify that wall self-weight either be applied to the top of the wall (as was done previously) or applied at each of the mesh nodes. This is particularly important for slender tilt-up walls.
Distorted Shell Mesh Warnings
During the process of meshing the floor diaphragms for Semi-rigid and two-way diaphragms, RAM Frame investigates the integrity of the resulting mesh elements. If the mesh element is highly distorted an error message is given, indicating that it won’t be included in the analysis. Previously those warnings were given one element at a time. These warnings have now been consolidated: a warning will be given that the condition occurs and lists the location (the Reports directory) where a file can be found listing all occurrences of a distorted mesh elements with their coordinates.
Note: this condition is usually caused by the side of a deck polygon not aligning exactly with a wall, beam, or other deck polygon edge. If this is the cause, the analysis results will likely be incorrect if the condition is not corrected by moving the polygon edge to correctly align with the members or other polygons.
Concrete Wall Criteria
In the Concrete Wall module, new criteria items for concrete walls have been add:
- In the Criteria – Design Criteria command, the Clear Bar Cover for Interior conditions vs Exterior conditions can be specified. Separate values for Cast-in-place vs Tilt-up can be specified. When walls are added in the Modeler the wall faces are specified as either Interior or Exterior; the Layout – Walls – Change Properties command can be used to modify those specifications.
- In the Criteria – Design Criteria command there is a Bar Placement section in which to indicate which bars, vertical or horizontal, are closest to the face. Separate designations for Cast-in-place vs Tilt-up can be specified.
- Using the Assign – Wall Panel Reveal Depths command, reveal depths can be specified and assigned to wall panels. This impacts bar placement and section properties (the wall design thickness is reduced by that amount).
India IS 456 Concrete Design
Design of concrete members per India IS 456 is now available. Design is performed by launching the STAAD RCDC program (RCDC V6.2 or later must be installed). This is invoked by setting the design code to IS 456 in the Criteria – Code command in RAM Concrete, and then selecting IS 456 Design in the Mode drop-down. All of the necessary geometry and member force information is exported to RCDC, where all of the powerful India concrete design capabilities of RCDC are available.