Buckling behaviors of section aluminum alloy columns under axial compression

• Seven irregular shaped aluminum alloy columns were tested.
• Effects of plate thickness on buckling stress and buckling mode were presented.
• Direct strength method can give accurate predictions on ultimate strength.

Thin-walled columns with section are used widely as columns in aluminum alloy framed structures, offering high strength-to-weight ratios and convenience in connection with maintaining walls. In this paper, thin-walled aluminum alloy columns with section were studied experimentally and numerically to investigate the buckling behavior and to assess the accuracy of current design methods. A finite element model (FEM) was developed and used to perform parametric studies after being verified by tests. Effects of plate thickness on elastic buckling stress was studied using finite strip method (FSM) and to find the potential buckling failure mode at a given length. Tested ultimate strengths were compared with those predicted by the current American, European and Chinese specifications on aluminum alloy structures and the Direct Strength Method (DSM) on thin-walled structures. Following reliability analysis, the design strength predicted by current design specifications were found to be generally conservative, whereas DSM offered more accurate results.