Inversion performance and multi-objective optimization of multi-component conical energy absorber with a spherical cap

This paper presents the quasi-static free inversion behavior of a new conical tube absorber. The absorber is composed of a multi-component conical tube with a spherical end cap and varying lengths and diameters. When this structure undergoes an axial load, each tube component freely inverts inside the next component like a telescope. Finite element (FE) models were made using ABAQUS explicit code to simulate the deformation and energy absorption of multi-component conical tubes. To verify the accuracy of the FE models, they were validated with experimental tests. As a general framework for a design optimization study, structural parameters such as wall thickness, cap radius, and edge length of the absorber affect the initial peak load and specific energy absorption. To achieve the optimal design for the multi-component conical tube, mathematical models were developed using the response surface method, and the multi-objective optimization procedure was applied to find the optimal values for the design variables. The results of the multi-objective optimization demonstrated improvements in both objective functions compared to existing designs. Specifically, by increasing the cap radius and decreasing the edge length, the initial peak load was reduced, while increasing the wall thickness the specific energy absorption was enhanced.