I have a couple of questions concerning the rotation of singe angle members. Which command should I use to rotate these angle members? "Beta Angle" or "Beta 45" (or 135 or 225 or whatever your required angle is)? I pose this question because I would have thought the results would have been the same but they are not. The results for "Beta Angle" actually match those of an angle member modeled along its principal axis with no rotation or "Beta 0". I also would have thought the properties for the weld design, namely Sz, Sy, CH & CV, would have changed with this "Beta Angle" command since the member end forces are no longer being applied in the same manner to the weld. Any thoughts?
You may want to take a look at the physical modeler of the STAAD.Pro CE version. The default orientation is with one of the legs parallel to one of the global planes. The program automatically determines and applies the beta angle to achieve that default.
Is the angle member a truss member or a frame member? Meaning, do you want it to carry axial forces only, or do you want it to carry bending and shears too?