Experimental and Numerical Study of Fixed-Ended High-Strength Aluminum Alloy Angle-Section Columns

Abstract

High-strength aluminum alloys are emerging and gaining increasing prominence in structural engineering. The structural behavior and design of 7A04-T6 high-strength aluminum alloy equal-leg angle-section columns under axial compression are investigated in this study. Eighteen experiments on extruded high-strength aluminum alloy angle-section columns with various lengths were carried out. Complementary material tests and initial geometric imperfection measurements were also performed. The test setup, procedure, and results, including failure modes, load-carrying capacities, and load–end shortening responses, are fully reported. The test program was followed by a numerical study, where refined finite-element (FE) models were first developed and validated against the test results and then utilized to carry out parametric analyses covering a wide range of cross-section dimensions and column lengths. Finally, the load-carrying capacities obtained from the tests and numerical analyses were used to evaluate the accuracy of existing design provisions in European, Chinese, and American standards for aluminum alloy structures and the direct strength method (DSM). The results show that the existing design methods generally yield good capacity predictions for fixed-ended members failing by flexural buckling, but rather conservative and scattered predictions when failure is by flexural-torsional buckling. Improved resistance predictions were achieved through application of a revised DSM-based approach.