Structural performance of aluminium alloy channel section tensile members connected with gusset plates

Aluminium alloy becomes increasingly popular in the construction industry due to its light self-weight, exceptional corrosion resistance and the ability to be fully recycled. This paper presents experiments and numerical simulations on aluminium alloy channel section tensile members connected with gusset plates. The experimental programme was conducted on 19 aluminium alloy channel section tensile member specimens, with either channel flanges or webs connected with gusset plates. The experimental failure loads, load–elongation curves, net section fracture behaviour and longitudinal strains at critical sections were reported, together with the influences of the connection length and eccentricities on the net section efficiency analysed. Numerical simulations were subsequently carried out, including development and validation of finite element models as well as parametric studies to generate further numerical data over a wide range of channel section sizes and connection lengths. The experimental and numerical results were used to evaluate relevant codified design provisions specified in the European, American and Australian/New Zealand standards. The evaluation results revealed that (i) the European code resulted in conservative and scattered predictions, underestimating actual failure loads by an average of 24 %; (ii) the American code offered unsafe and scattered predictions, overestimating load-carrying capacities by an average of 26 %; and (iii) the Australian/New Zealand standard led to conservative and scattered predictions for the web-bolted scenario but relatively accurate and consistent predictions for the flange-bolted scenario. Consequently, a new set of design equations was then proposed by properly considering all key influencing geometric parameters, including connection length and out-of-plane as well as in-plane eccentricities, and shown to offer substantial improvements in the design of aluminium alloy channel section tensile members connected with gusset plates.