Answer:
The internal forces and deformations are determined according to the second-order analysis for torsional buckling, taking into account 7 degrees of freedom. For a linear calculation of deformations, a vertical or horizontal load only results in one vertical or horizontal deformation. Since the internal forces refer to the deformed structure and there is a nonlinear analysis, this is not valid for the second-order torsional buckling analysis.
In RFEM 5 and RSTAB 8, you can check the deformations in the shear center by using the RF‑/FE‑LTB add-on module (see Image 02). The deformations that additionally result from the displacements or rotations can only be checked with a surface model in RFEM 5.
