Post-Fire Behaviour of 7075-T6 High-Strength Aluminium Alloy Tubular Section Stub Columns

This paper presents experimental and numerical investigations on the local buckling behaviour and compressive resistances of 7075-T6 high-strength aluminium alloy circular hollow sections after exposure to elevated temperatures. The testing programme was firstly conducted, including heating tests, post-fire material tensile coupon tests, initial local geometric imperfection measurements and sixteen stub column tests after exposure to eight levels of temperatures ranging from room temperature to 550 oC. The experimental investigation was supplemented by a numerical modelling investigation, where finite element models were firstly developed and validated against the post-fire stub column test results, and afterwards used to carry out numerical parametric studies. The obtained test and numerical data were analysed and employed to conduct a design analysis, in which the applicability of the relevant room-temperature design rules in the current European, American and Australian/New Zealand standards as well as the continuous strength method to the post-fire design of high-strength aluminium alloy circular hollow sections under compression was evaluated.