The Torsional Warping (7 DOF) add-on allows you to consider the cross-section warping as a 7th degree of freedom. degree of freedom in the global calculation of RFEM 6 and RSTAB 9. In this case, the warping is considered as a local member deformation, but it is considered as part of the calculation of the Global Model. The stiffness of the adjacent structural components is automatically taken into account.
You can find the same options in the static analysis settings as for the calculation with 6 degrees of freedom.
Please note that a sufficiently fine FE mesh division is required for correct consideration of the cross-section warping in RFEM. It is recommended to use at least 8-10 divisions per member. You can specify the size of finite elements as well as the minimum number of member divisions in the static analysis settings. In RSTAB, no division is necessary.