Warping and bimoment transmission through diagonally stiffened beam-to-column joints

For beam-to-column rigid joints with a diagonal stiffener, the warping degrees of freedom at the beam-to-column joint have been taken to be continuous in some current literature. A new warping transmission model is presented for this type of joint in this paper, in which the bending deformation and twisting of the diagonal stiffener are considered and the restraining of the web in the joint panel zone to the twist of the diagonal stiffener is taken into account. Comparison with FEA using shell elements demonstrated the high accuracy of the proposed model, while the results with the continuous warping assumption have greater deviation with the finite element results. The suggested model can be implemented simply though modifying the traditional thin-walled beam element matrix at the joints. The proposed model is applicable for solving combined flexural and torsional problems of frames composed of thin-walled members.