March 12, 2015
Cold-Formed Steel Back to Back Design
Cold Formed Steel channels are often built-up as back-to-back sections to help strengthen them. RISA-3D can design the Cold Formed Steel back-to-back channel and track sections. The Shape Selection dialog will allow you to model the built –up sections by selecting “Back to Back” shown below.
There are a variety of different code checks that are done for back to back sections per the AISI and these are all done automatically for you. There is one new parameter required by RISA, the spacing of the connections between the back-to-back members in order to properly calculate the slenderness (KL/r). This additional spacing input required is listed as “a” in the Properties Panel or the Member spreadsheet:
The Detail Report for Back-to-Back members shows all the controlling section properties including Effective Area, Section Modulus, and Moment of Inertia.