Study of Bearing Capacity of Aluminum Alloy Thin-Walled Circular Tube Filled with Lightweight Filler

In this study, experimental research, a numerical simulation, and a theoretical analysis were performed on the bearing capacity of an aluminum alloy circular tube filled with a lightweight filler (ATLF). Bearing capacity tests were conducted for six ATLF columns and two aluminum alloy hollow tubes (AAHTs), and their local buckling failure modes and mechanical properties were obtained. A finite element model was developed using ABAQUS software (ABAQUS 2016, ABAQUS Inc., Palo Alto, CA, USA) for numerical calculations. Furthermore, a large-scale numerical analysis was performed to investigate the effect of structural parameters, such as the tube thickness, diameter, column length, and initial geometric imperfections, as well as the aluminum alloy’s properties and the lightweight filler’s properties, on the bearing capacity of the ATLF columns and AAHTs under axial compression. Based on the test and numerical analysis results, a formula for calculating the local buckling stress of AAHTs under axial compression is proposed. An improved coefficient of bearing capacity for the ATLF columns caused by the internal lightweight filler was obtained by fitting, and based on the results, a formula for computing the bearing capacity of ATLF columns under axial compression is proposed in this study.