Torsion warping transmission at thin-walled frame joints: Kinematics, modelling and structural response

This paper reports on the use of simple kinematic models to simulate the torsion warping restraint and transmission at thin-walled frame joints in the context of beam finite element structural analysis. After reviewing the main concepts involved in the torsional behaviour of thin-walled members, the paper addresses the development of kinematic models aimed at simulating the torsion warping transmission at frame joints connecting two or more non-aligned plain channel (U-section) or I-section members. Finally, numerical results are presented and discussed, in order to illustrate the application and show the capabilities of the above kinematic models, which make it possible to use beam finite element models accounting for the joint torsion warping behaviour. For validation purposes, the beam finite element results obtained are compared with values yielded by rigorous shell finite element analyses.