Analysis And Optimization Of The Energy Absorption Of Aluminum Foam-filled Tubes By Contact Model And Inducing Grooves

In low-speed collision, thin-walled metal tube filled with aluminum foam has been regarded as a crash box with ideal performance. Experts and scholars have made various studies on aluminum foam、thin-walled metal tube and coupling structure of both,and have made certain progress. Based on scholars’ research on aluminum foam-filled thin-walled metal tube, the purpose of this thesis was to put forward an aluminum foam-filled thin-walled structure with inducing grooves and optimal contact strength, and its energy absorption performance was analyzed.The definition of the contact strength parameters between the aluminum foam core and the thin-walled metal tube directly affects the interaction of the two parts. In this paper, the optimal contact parameters between the aluminum foam core and the thin-walled metal tube was found out, the optimal contact model was obtained. On this basis, the effect of the inducing grooves on the energy absorption property of the aluminum foam-filled thin-walled metal tube was learnt. By analyzing the influence of the contact strength and the inducing grooves on the energy absorption property, aluminum foam-filled thin-walled metal tube with optimal energy absorption performance was achieved. The research was carried out from the following three aspects:Firstly, based on the test, the 3D model was built by CATIA, the material and property of aluminum foam core and thin-walled metal tube were defined by HYPERMESH, the finite element model was established, and the grid quality and element size were checked. According to the loading type of the tests, constraints and loads of finite element model were defined. The keyword file of the finite element model was calculated by the LS-DYNA solver, and the result was outputted. Based on the test and simulation results, the deformation mode and crashing force curve were compared. The comparison results showed that, test and simulation had a certain degree of matching within the admitted tolerance, the reliability of the finite element model was verified. So the finite element model could be used to replace the test model on further analysis and optimization.Secondly, the influence of contact strength for aluminum foam core and thin-walled aluminum tube on energy absorption performance was analyzed. Different level of finite element contact models which simulate the contact strength of aluminum foam core and thin-walled metal tubes were built, and the conclusion was drawn: the contact strength of aluminum foam core and thin-walled metal tube has a certain influence on the energy absorption performance. Finite element simulation based on orthogonal test design method were arranged, samples of cubic polynomial response surface was drawn by MATLAB. Optimal energy absorption performance of the certain parameters of the contact strength was carried out by multi-objective particle swarm optimization(MOPSO).Finally, based on the optimization results of optimal contact strength, two inducing grooves in the middle and upper position of aluminum foam-filled metal tube were set, the finite element model of aluminum foam filled thin-walled metal tube with different induction grooves and contact strength was established:(1)with inducing grooves and optimal contact model;(2)without inducing grooves and optimal contact model;(3)without inducing grooves and traditional interference fit, and the energy absorption property were contrasted. Through the comparative analysis, the conclusion was drawn: compared with typical aluminum foam-filled metal tube, aluminum foam-filled metal tube with optimal contact strength and inducing grooves is relatively better in energy absorption performance.