Flexural buckling of stainless steel CHS columns: Reliability analysis utilizing FEM simulations

Abstract

This paper presents a numerical investigation of the ultimate limit state of imperfect columns under axial compression; the columns are made of stainless steel with a circular hollow cross-section (CHS). The subject of interest is the statistical analysis of the ultimate resistance. Statistical characteristics of input material and geometric imperfections are taken from the results of experimental research published in the literature. The first-order reliability method (FORM) along with geometrically and materially nonlinear imperfect numerical analysis (GMNIA) is conducted. The ultimate resistances of CHS columns in flexural buckling obtained from the finite element analyses are compared with the design resistances based on the corresponding European standard, considering various slenderness values. Two approaches of the initial geometrical imperfection amplitude consideration are presented. The influence of correlation between the ultimate resistance of stainless steel columns in compression and input parameters is discussed, with a focus on the geometrical imperfection influence. The results may be useful for the verification of the European standard where the flexural buckling curves of stainless steel columns are relatively new and thus are based on a relatively weaker theoretical and experimental basis compared to carbon steel.