June 3, 2022

Match Properties in RISA-3D

RISA-3D now includes the ability to "match properties" between members. For more information about this feature, check out the video below:

Tags: RISA-3D, Properties, New, Members

January 17, 2019 | RISAFloor, Diaphragms, New

RISAFloor & RISA-3D: Two Buildings on the Same Podium

RISAFloor is the RISA Building System’s floor design software which allows users to design with composite decks, elevated concrete slabs and more. When paired with RISA-3D, the two create a complete solution for the analysis and design of multi-story structures, including two buildings on the same podium. Equivalent Lateral Force/Static Force Procedure After the definition of slab edges and the application of diaphragms in RISAFloor, RISA-3D is used to determine the different lateral forces that need to be attributed to each individual diaphragm that exists at each elevation. These story forces can then be displayed graphically (as shown below) per diaphragm at each elevation. Dynamic Analysis If your building requires a dynamic analysis, mode shapes can be calculated and displayed in the same fashion as they are for a single structure. Similarly, building frequencies and mass participation’s are just as simple to retrieve by simply choosing “frequencies” or “mode shapes” from the Results Toolbar or the Results menu drop-down. Intermixing Diaphragm Types RISA also allows users to analyze with different diaphragm types (flexible, semi-rigid, rigid) at the same elevation of your separate buildings. Using RISAFloor paired with RISA-3D, engineers can analyze and design complex structures with this configuration. In addition,…

August 17, 2016 | RISA-3D, New, Warping, Torsion

How Does RISA-3D Account for Torsional Warping?

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. The primary reference used in the development of RISA-3D’s torsional calculations was the AISC Design Guide #9, Torsional Analysis of Structural Steel Members. It is important to remember that RISA-3D models warping members using CASE 2 only. As shown in the Torsion reference, CASE 2 represents the torsionally fixed and warping fixed end conditions for the member. Thus, a member would be then subjected to an equal and opposite point torque at the end of the member. Note: RISA’s calculation of torsion stresses is good for capturing the torsion due to racking of the structure, not point or line torques on an individual member. That type of check is not supported. Stress Results RISA-3D calculates and lists the torsional stresses for the members of the structure, including the warping stresses. These are reported in the Member Torsion spreadsheet. For warping shapes (I’s and C’s), three separate stresses are calculated: pure torsion shear, warping shear and warping normal (bending) stresses. Code Check Results These torsional…

January 2, 2014 | RISA-3D, New, RISASection

Designing Built-Up Sections using RISA-3D

Use RISASection to find the properties of built-up steel sections, then model beams using the same section properties in RISA-3D and get full code-checks using AISC 360. This webinar will teach you how to use RISASection quickly and easily to determine complex section properties…