Research On Energy-Absorption Ability Of Foam Aluminum And Its Application In Automotive Bumper

With the rapid development of the auto industry, the number of cars on the city roads becomes more and more large, and the sharp increase in the amount of vehicles has brought many traffic security problems. To minimize the maintenance cost caused in low-speed collisions, we require that the bumper should have good energy-absorption effect. With the application of LS-DYNA, this paper studied the energy-absorption ability of foam aluminum–a new functional material to equip car bumpers with better energy-absorption effect, and compared the energy-absorption effects of bumpers with aluminum-foam filled tubes and ordinary tubes.In this paper, the evaluation criterion for the bumper in collisions was specified, and according to the criterion, the energy-absorption ability of bumpers was evaluated too. Based on the structure characteristics of foam aluminum, finite element models of foam aluminum of different densities were established. Besides, the energy-absorption curves and wallop curves of foam aluminum were obtained by utilizing LS-DYNA to carry on the impact simulation. The finite element models of foam aluminum and the simulation were proved accurate by comparing between the curves and the tests data. The simulation results showed that the foam aluminum is a kind of excellent energy- absorption material and its energy-absorption efficiency can reach 70 percent. Especially for the material of the density of 0.56 g/cm~3, it has superior ability of energy-absorption and impact alleviating than others.This paper compared and analyzed the energy-absorption effects in the axial compression process between aluminum-foam filled tubes and ordinary hollow tubes used in bumpers. The conclusion was drawn that the aluminum-foam filled tube's energy-absorption effect is much better than that of ordinary hollow tubes. It has been discussed about the energy-absorption effects of aluminum-foam filled tubes under different parameters. By comparing aluminum-foam filled tubes of different wall-thicknesses, cross sectional shapes, and tubes of different materials and lengths, the parameters of aluminum-foam filled tubes for better energy-absorption effects were obtained in the paper.After determining the parameters of aluminum-foam filled tubes, the energy-absorption effects of aluminum-foam filled tubes and ordinary tubes under the parameters were analyzed using LS-DYNA. By analyzing the energy-absorption effect between pipes filled with foam aluminum with rectangular section and ordinary hollow aluminum pipes with round section applied to car bumpers, the results showed that pipes filled with foam aluminum, the same weight as hollow aluminum pipes, the amount of energy-absorption increases 71 percent.Aiming at studying the energy-absorption ability of foam aluminum, the result showed that the bumper with aluminum-foam filled tubes enjoyed great advantage on aspects of both energy-absorption and lightweight. The paper supplied bases for foam aluminum materials in the application of car bumper, and also provided valuable references for the design of bumpers with better energy-absorption ability.