Numerical simulation of local-distortional buckling behavior of lipped C-section stainless steel columns

Abstract

The stainless steel components with lipped C-section are prone to Local-Distortional Interaction Buckling (LDIB) failure when subjected to compressive load, whereas the design formula of LDIB capacity has not been well-established so far. As a follow-up work of previous experimental study, this paper aims to conduct a parametric study on the LDIB behavior of lipped C-section stainless steel columns through numerical simulation and propose the relevant calculation formulas of LDIB bearing capacity. The factors governing the buckling behavior include the initial geometric imperfection mode, the local-distortion buckling slenderness ratio, the corner region material strength improvement, and the nominal yield strength of the stainless steel materials. Based on the validated Finite Element (FE) model, the LDIB capacity of 169 lipped C-section stainless steel columns with strong-axis rotation and 201 lipped C-section stainless steel columns with weak-axis rotation were numerically computed, and the calculation formulas of LDIB capacity were then proposed using the direct strength method. Based on the comparative study, the proposed formulas deliver enhanced accuracy and robustness than the existing formulas and hence could be employed reliably for the design of lipped C-section stainless steel columns.