Plastic collapse load numerical evaluation of welded beam-to-column steel joints

摘要

A finite element based numerical procedure for predicting the plastic collapse load as well as the plastic collapse mechanism of beam-to-column steel joints is presented. The promoted procedure is based on two methods following the static and the kinematic approach of limit analysis. Both methods have been rephrased for a von Mises type material in the deviatoric plane and in terms of deviatoric stress invariants. The key concepts are: i) in the static formulation, to mimic the stress redistribution arising within a structure approaching its critical (collapse) state, such stresses being in equilibrium with the maximum redistributable loads; ii) in the kinematic formulation, to build a plastic collapse mechanism characterized by compatible strain and displacement rates corresponding to a minimum value of loads doing positive work equal to the total plastic dissipation. A validation of the numerical results is pursued by comparison with experimental findings on real scale prototypes of the tackled steel joints. Future developments are outlined at closure. (C) 2017 Elsevier Ltd. All rights reserved.