Local – distortional interaction buckling of stainless steel lipped C-section beams

Abstract

Based on a bearing capacity test of 10 specimens composed of 20 stainless steel lipped C-section components, a refined finite element model was established and verified to investigate the failure mode and bearing capacity. 267 numerous parametric analyses were carried out to investigate the effects of the distribution and amplitude of initial geometric imperfections, strength improvement of corner and buckling slenderness ratio on the buckling modes and bearing capacity of stainless steel beams. The effects of both distribution and amplitude of initial geometric imperfections on the bearing capacity were significant. However, the effect of amplitude of initial geometric imperfections on the buckling modes was small. When the ratio of cross-sectional area of corner to the whole cross-sectional area was smaller than 5%, the increase of strength improvement of corner to the bearing capacity was within 5%. When the ratio was larger than 5%, the increase was more significant. The existing methods for calculating the bearing capacity of local – distortional interaction buckling of carbon steel and high-strength steel lipped C-section beams underestimate that of stainless steel lipped C-section beams. Therefore, two design methods for local – distortional interaction buckling of stainless steel lipped C-section beams based on Direct Strength Method were proposed for the first time. A reliability analysis of the proposed methods was conducted to verify the reliability for engineering application.