6A13-T6 high-strength aluminium alloy columns under axial compression: Experiments, finite element analysis and design recommendations

Novel high-strength aluminium alloy 6A13-T6 is interesting for its exceptional mechanical properties. Its mechanical performance is understudied, hindering its utilization in the construction industry. This paper reports the experimental results of material tensile and axial compression tests carried out on 8 members. After the test, the finite element models were developed by ABAQUS and validated with the test results. Then, finite element parameter analysis was carried out, and the bearing capacity was compared with the values calculated based on the codes of China and the United States. In addition, column compression's mechanical essence is explored using the finite element refined analysis method. Finally, the overall stability coefficient of the Chinese codes was modified. The results show that the nonproportional yield strength of 6A13-T6 is 340 MPa, the ultimate strength is 352 MPa, and the elongation after fracture is 14.5%, which is much better than other 6-series aluminium alloy materials. Due to the large width-thickness ratio of the section, significant local buckling occurs in all members. With the increase in the slenderness ratio, the failure mode of the member changes from local buckling failure to the coupling failure mode of global buckling and local buckling. Good ductility can fully develop the section stress, so the bearing capacity calculated by the finite element models is greater than the predicted value in the codes. With the adjusted overall stability factor calculation formula, designers and engineers can more economically design 6A13-T6 high-strength aluminium alloy axial compression members.