Local buckling behaviour and design of aluminium alloy plates in fire

This paper presents a comprehensive study into the local buckling behaviour and design of aluminium alloy plates in fire. Finite element (FE) models were firstly developed to replicate the structural performance of aluminium alloy plates in fire obtained from fire tests collected from the existing literature. Upon validation of the FE models, comprehensive numerical parametric analyses were carried out considering a wide range of aluminium alloy grades, plate slendernesses, temperature levels as well as boundary and loading conditions. The obtained numerical results were then utilised to evaluate the accuracy of current design methods for aluminium alloy plates in fire. It has been found that the current design methods provide inaccurate and scattered resistance predictions for aluminium alloy plates in fire. To address the shortcomings of the existing design approaches, new cross-section classification limits and effective thickness method, taking due consideration of the variation in strength and stiffness of aluminium alloys at different elevated temperatures, were proposed. The new method is shown to be able to eliminate the discontinuity of the resistance predictions of aluminium alloy plates in fire in the European code and provide an improved level of buckling resistances, in terms of accuracy and consistency.