In the RISA-3D when you model a WT brace it exists at the member centroid, which means that no bending ends up in the brace due to the fact that the brace is actually eccentric to the braced frame.
Seismic Forces are generated automatically using seismic parameters R, SD1, and SDS in the Seismic Load Generator when using the Director to go from RISAFloor to RISA-3D or when inserting Seismic Loads on a rigid diaphragm in RISA-3D. Additionally, Seismic Load Combinations can be generated using...
In a model that contains both RISAFloor and RISA-3D data it is possible to define your diaphragms as either flexible or rigid for lateral design. You can do this from the Diaphragms spreadsheet in either program:
In RISA-3D’s addition of the AISC 14th Edition code we added Section E4 checks to wide flange members. Section E4 is Torsional and Flexural-Torsional Buckling of Members Without Slender Elements and is for compression capacity.
Twisting of a member or frame induces torsional forces and stresses. This is included in the RISA-3D analysis as long as you have the Torsional Warping checkbox selected on the Solution tab of (Global) Model Settings.
When using RISA Integration between RISASection and RISA-3D, RISA-2D and/or RISAFloor, there are a few common mistakes that people make when attempting to access the RISASection files from the Shape Database.
Wall Panel Forces Spreadsheet The power of RISA is the easy to access output. The Wall Panels have all the calculations and forces displayed in the Detail Report and now the new Wall Panel Forces gives you a quick way to get all the forces across the base of the wall. This new spreadsheet can be...
You may find that when looking at the Code Check spreadsheet that a given member is failing in design. Here is an example where a steel brace is failing in bending.
The Pacific Earthquake Engineering Research center (PEER) has a large library of measured earthquake records. Below is an example of how to quickly convert one of these records into a format that can be imported into RISA.
