Stability performance of thin-walled pultruded beams with geometric web-flange junction imperfections

Abstract

The current paper investigates the role of initial imperfections at web-flange junction on the lateral torsional buckling behavior of pultruded fiber reinforced polymeric beams. This study is based on experimental and numerical results, which are developed in two main steps: perfect beams and beams with initial imperfections at the web-flange junction. In the first step, small-scale tests are carried out to calculate the mechanical properties of the composite section. Perfect and imperfect pultruded I- and C- shaped beams are subjected to full-scale experimental tests under an applied four-point bending load with a total lengths varying from 1500 to 3000 mm, and 2500–3500 mm for the I- and C-beams, respectively. The end conditions of all beams studied are simply supported. Perfect beams are tested to investigate their dominant failure mode, as well as the impact of lateral bracing on the failure modes. While, imperfect beams are tested to determine the effect of initial imperfections on the lateral-torsional buckling capacity and failure mechanisms.