Buckling resistance of stainless steel welded L-columns

Stainless steel is characterised by its nonlinear stress-strain behaviour with significant strain hardening. However, currently available design codes treat it as elastic and perfectly plastic material like carbon steel, which leads to conservative predictions. A new design approach called the Continuous Strength Method (CSM) has recently been developed for nonlinear metallic materials to exploit the beneficial effect of strain hardening and to eliminate the effective width approach. Recently a proposal was made to calculate the buckling capacity of rectangular hollow sections (RHS) and square hollow sections (SHS) combining CSM with Perry curves. In this paper, that proposal is extended for welded l-section. Using finite element technique the behaviour of welded l-section was investigated for major and minor axis buckling. It is observed that, behaviour of column buckling about major axis is different from that of minor axis buckling and required separate column curves. It is also found that, cross section slenderness AP has a significant effect on column capacity. The shapes of column curves are mostly affected by V Hence imperfection factor r\, as used in Perry formulations, is expressed as a sigmoidal function where coefficients of the sigmoidal function were expressed as a function of AP. This technique yields separate column curves for different Ap values. Different functions for the coefficients are proposed for major and minor axis buckling. Performance of the proposed technique is compared with European guidelines.