Design of Aluminum Alloy Channel Section Beams

Aluminum alloy members of channel sections are widely used in lightweight structures, especially as pillars of curtain wall systems and brace and chord members in roof trusses. This paper presents both experimental and numerical studies on the behavior of aluminum alloy channel section beams. In this study, four-point bending tests under minor-axis and major-axis bending were carried out. The test specimens included plain and lipped channel sections of both 6063-T5 and 6061-T6 aluminum alloys. A finite-element (FE) model of the channel section beam was developed by using the FE package ABAQUS. The ultimate bending resistances and failure modes of the FE model were compared with the results from the bending tests. The validated model was employed for the parametric study to generate numerical simulation results. A total of 55 new experimental and numerical beam results were compared with predictions from existing aluminum alloy design specifications from the United States, Australia/New Zealand, Europe, and China. Additionally, two commonly used design approaches—the continuous strength method (CSM) and the direct strength method (DSM)—were applied to predict bending capacities for comparisons. A modified DSM approach for aluminum alloy channel section beams is proposed herein. Finally, reliability analyses were conducted to evaluate the aforementioned design methods. The results show that, in comparison with other considered design methods, the CSM provides more accurate and consistent results for aluminum alloy plain and lipped channel section beams.