My application is actually off topic, but my question is general enough that I thought I would post it here. I was trying to model an aluminum truss structure using "L" 6061 extrusions, with the force from a 90 mph wind. There was a warning about "twist-bending coupling not being modeled results may not be accurate." I would say so! It was giving displacements in the region of 40Km! Does anyone know how to model a truss made from "L" extrusions? What I am using is "Mecway" freeware, a cousin of the Lisa software.