Effective Width of Locally Buckled Plates in Compression and Bending

Abstract

The effective‐width concept has been recognized as an efficient way to compute the strength of locally buckled thin‐walled members. In a previous paper, an effective‐width formula for a locally buckled plate in combined compression and bending was presented. The formula was derived from the numerical results of an elastic postbuckling analysis of plates subjected to eccentric loading in its plane. The present paper is aimed to extend the previous study. An elastic‐plastic large‐displacement finite element (FEM) analysis has been performed to compute the ultimate strength of simply supported, initially imperfect steel plates in compression and bending. The plate is assumed to possess initial out‐of‐flatness as well as welding‐type residual stresses. Based on an extensive numerical study, a set of new effective‐width formulas have been derived as functions of both the magnitudes of initial out‐of‐flatness and compressive residual stress. Thus, the formulas could be used to predict the strength variations of various plate‐assembled members in combined compression and bending.