Warping torsion is drilling with restrained axial displacement or forced torsion.
Warping torsion occurs in the cross-sections that are not free to warp, if the warping of the end cross-sections is restrained. The non-free-to-warp cross-sections include, in particular, open thin-walled steel cross-sections. On the other hand, a circle, a circular ring, and a square hollow cross-section with constant wall thickness, are free-to-warp cross-sections.
Usage in Program
You can perform the warping analysis, taking into account the cross-section warping, using the Warping Torsion (7 DOF) add-on. It allows you to perform lateral‑torsional (flexural-torsional) buckling analyses of members according to the second‑order theory with 7 degrees of freedom and the application of imperfections with regard to mode shapes.