Experimental study of local buckling behaviour of 7A04-T6 high strength aluminium alloy H-section stub columns in fire

This paper presents a comprehensive experimental investigation into the local buckling behaviour of 7A04-T6 high strength aluminium alloy H-section stub columns in fire. The experimental programme comprises six room temperature tests and eighteen steady-state fire tests on 7A04-T6 high strength aluminium alloy H-section stub columns. In addition, complementary tensile coupon tests at room temperature and initial local geometric imperfection measurements of the stub column specimens were undertaken. The study meticulously details the test setup, procedures, instrumentation and key results, including failure modes, ultimate resistances and load-end shortening curves of the test specimens. The obtained test results are utilised to assess the applicability and accuracy of existing fire design rules outlined in European, Chinese and American standards, the design recommendations presented by Han et al. [1] and Maljaars et al. [2] for aluminium structural components in fire, as well as the recently developed deformation-based method named the Continuous Strength Method. The findings indicate that the existing design approaches provide conservative predictions of ultimate resistances for 7A04-T6 high strength aluminium alloy H-section stub columns in fire to varying degrees, highlighting the imperative need for further refinement of the design rules to enhance their predictive accuracy.