Experimental and numerical investigations of hot-rolled stainless steel channel section columns susceptible to flexural buckling

Abstract

A thorough testing and numerical modelling programme has been conducted to investigate the minor-axis flexural buckling behaviour and resistances of pin-ended hot-rolled stainless steel channel section columns. The testing programme included material coupon tests, membrane residual stress measurements, initial global and local geometric imperfection measurements and ten pin-ended channel section column tests about the minor principal axis. A membrane residual stress predictive model was developed based on the measured data. The testing programme was followed by a numerical modelling programme; finite element models were developed to simulate the test results and then adopted to perform parametric studies to generate further numerical data on hot-rolled stainless steel channel section columns over a wide range of cross-section dimensions and member effective lengths. The obtained test and numerical data were then adopted to assess the accuracy of relevant design rules for hot-rolled stainless steel channel section columns failing by flexural buckling about the minor principal axis, as given in the European code and American design guide. The assessment results revealed that (i) the European code yields many unsafe flexural buckling resistance predictions and (ii) the American design guide yields overly conservative and scattered flexural buckling resistance predictions. Finally, a revised Eurocode buckling curve was proposed and shown to offer accurate, consistent and safe-sided flexural buckling resistance predictions for hot-rolled stainless steel channel section columns over the whole considered range of member non-dimensional slendernesses. The reliability of the revised Eurocode buckling curve was also confirmed using statistical analyses based on EN 1990.