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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.

A test program was performed on cold-formed-steel oval hollow sections under axial compression. The test specimens were cold-rolled into oval hollow sections with flat web plates and semicircular f...

This paper presents the experimental and numerical investigation of aluminum alloy flexural members. The tests were performed on ten different sizes of square hollow sections subjected to pure bending. Material properties of each specimen were obtained from tensile coupon tests. A nonlinear finite-element model was developed and verified against the pure bending tests. Stress-strain relationships obtained from tensile coupon tests were incorporated in the finite-element model. The verified finite-element model was used for a parametric study of aluminum alloy beams of square hollow sections. A comparison of the experimental and numerical bending strengths with the design strengths calculated using the current American, Australian/New Zealand, and European specifications for aluminum structures was presented. The bending strengths were also compared with the design strengths predicted by the direct strength method, which was developed for cold-formed carbon steel members. Design rules were proposed for aluminum alloy square hollow section beams based on the current direct strength method. Reliability analysis was performed to evaluate the reliability of the design rules.

This paper presents a test program on aluminum alloy thin-walled square and rectangular hollow sections in combined axial compression and minor axis bending. A total of six series of tests was conducted that included 27 beam-column and 4 pure bending tests. The test specimens were manufactured by extrusion using 6061-T6 heat-treated aluminum alloy in three different cross sections having the clear width-to-thickness ratio ranged from 31.3 to 81.3. The beam-column specimens were compressed between pinned ends at different eccentricities in order to obtain an interaction curve for each series of tests. Pure bending tests were conducted for each test series to determine the bending capacities of the specimens. Local and overall initial geometric imperfections of the specimens were measured. Material properties were obtained from tensile coupon tests. The observed failure modes of the beam-column tests included local buckling, flexural buckling, interaction of local and flexural buckling, and material yielding in the heat-affected zone. The test strengths were compared with the design strengths calculated using the American, Australian/New Zealand, and European specifications for aluminum structures. Beam-column interaction curves were plotted for each test series. It is shown that the beam-column design strengths and bending capacities predicted by the three specifications are generally conservative.

A test program was performed on aluminum alloy columns of square and rectangular hollow sections that were compressed between fixed ends. In total, five series of tests were conducted that included columns with both ends transversely welded to aluminum end plates using the tungsten inert gas welding method, and columns without welding of end plates. The tests were performed over a range of column lengths in order to obtain a column curve for each series of test. Heat-treated aluminum alloys of 6063-T5 and 6061-T6 material were used for the column specimens. Nonwelded and welded material properties were obtained from various coupon tests. The column specimens failed by local buckling, overall buckling, as well as interaction of local and overall buckling. In addition, some welded columns failed in the heat-affected zone. The test strengths were compared with the design strengths predicted by the American, Australian/New Zealand, and European specifications for aluminum structures. Reliability of the design rules for transversely welded aluminum columns in the three specifications was examined using reliability analysis. It is shown that the design strengths predicted by the three specifications are conservative for the nonwelded columns. For the welded columns, the design strengths predicted by the American and Australian/New Zealand specifications are generally conservative, whereas the design strengths predicted by the European Code are relatively quite conservative. It should be noted that the design strengths predicted by the American and Australian/New Zealand specifications are unconservative in some cases for the welded columns.