Numerical investigation on buckling resistance of stainless steel hollow members

Structural stainless steel requires appropriate recognition of its beneficial properties such as material non linearity and significant strain hardening. The Continuous Strength Method (CSM) exploits those benefits through a strain based approach for both stocky and slender cross-sections. In this paper, a new design method is proposed that combines the CSM design principles with Perry type buckling curves for stainless steel square and rectangular hollow sections (SHS and RHS) subjected to compression. Numerical models were developed to investigate effects of various parameters on column strength and to develop complete column curves for hollow members. It was observed that cross-section slenderness lambda(p) and material properties such as non-dimensional proof stress e and strain hardening exponent n significantly influence column resistances. Effects of e and n were appropriately incorporated through introduction of correction factors to modify non-dimensional member slenderness. It was observed that the shapes of column curves were mostly affected by and hence imperfection parameter eta, as used in Perry formulations, was expressed as a function of lambda(p); this technique yielded separate column curves for different lambda(p) values. The proposed method includes the strain hardening benefits for stocky sections, and abolished the necessity of calculating effective cross-sectional properties for slender sections. Performance of the proposed technique is compared against those obtained by using the European guidelines.