Experimental and numerical investigations of hot-rolled austenitic stainless steel equal-leg angle sections

Abstract

The present paper reports a thorough experimental and numerical study on the cross-section behaviour and resistances of hot-rolled austenitic stainless steel equal-leg angle section structural members. The experimental programme was performed on a total of five different angle sections, and involved ten stub column tests and ten laterally restrained 4-point bending tests about the cross-section geometric axes (parallel to the angle legs), together with measurements on material properties and initial local geometric imperfections. The testing programme was followed by a systematic finite element simulation programme, where the developed numerical models were firstly validated against the experimentally derived results and then employed to carry out parametric studies for the purpose of generating further structural performance data over a broader range of cross-section dimensions. The numerically derived results were then employed together with the test data to assess the accuracy of the established design rules for hot-rolled austenitic stainless steel equal-leg angle section stub columns and beams given in the European code. The results of the assessment revealed an overly high level of conservatism and scatter of the European code in predicting cross-section capacities of hot-rolled austenitic stainless steel equal-leg angle section stub columns and beams, which can be mainly attributed to the neglect of the beneficial material strain hardening. The continuous strength method (CSM) is a well-established design approach, taking due account of material strain hardening in the determination of cross-section resistances, and has been recently extended to cover the design of mono-symmetric and asymmetric stainless steel open sections in compression and bending about an axis that is not one of symmetry. The CSM was assessed against the experimental and numerical results on hot-rolled austenitic stainless steel equal-leg angle section stub columns and laterally restrained beams, and shown to result in substantially more precise and consistent cross-section capacity predictions than the European code.