Finite Element Analysis to Investigate the Effect of Imperfections on RHS in Bending

摘要

This paper describes finite element analysis of cold-formed RHS beams, with particular reference to the effect of imperfections and corner radius on the rotation capacity of the beams. Introducing geometric imperfections into the model was essential to obtain rotation capacities that were close to the experimental results. To simulate the effect of the imperfections induced by welding the loading plates to the beams in the experiments, the amplitude of the bow-out imperfection was varied sinusoidally along the length of the beam. Attempting to simulate the imperfections caused by welding by imposing a temperature gradient on the elements comprising the weld did not have a major effect. The results on sections with a range of corner radii suggest that the trend between web slenderness and rotation capacity is described better when the clear width definition of slenderness is used, rather than the flat width definition.