The Optimization Study On The Crashworthiness Of The Automobile Crash-box

With the high-speed development of the economy, automobile has gradually become essential traffic tool for human in the modern society, however, with bring us great convenient, the high prevalence of automobiles also bring huge disaster for people, The manufacturing industry, the academic field, the governments and the consumers pay more and more attention to the automotive safety.In the low-speed crash, the crushing deformation of the crash-box structure helps energy absorption and converts the crash kinetic energy into the internal energy of the crash-box structure, besides crash-box also transfer the crash kinetic energy from the front beam to the front longitudinal beam, this play an important role in protecting the car and passenger from damage. Analyze the energy absorption property and deformation property of the crash-box during the crash process can help improve its energy absorption performance which has great significance to enhance the car’s passive safety.Based on the domestic and overseas references on the car crash safety, this paper comprehensive summarize the research methods, impact factors and other key issues of the crash-box performance during the crush. Through optimize the crash-box’s material and structure to improve its crashworthiness. During the finite element model processing, this paper simplified the vehicle finite element model and used two ways to do the analysis,indirectly verified the validity of the simplified model which provides great convenience for follow-up study and improves the simulate efficiency.In order to optimize the crash-box this paper use HyperMesh and LS-DYNA to do the analyze work. Firstly, use aluminium alloy as the thin-wall component material, the simulation result shows aluminium alloy crash-box has better performance than the low-carbon steel crash-box. Secondly, simulate the crash-box based on different cross-section shape, after comprehensive comparison this paper determines the hexagon structure is more suitable for the crash-box structure. Thirdly, in order to get the optimumstructure parameter this paper use nonlinear response surface optimization method to analyze the wall thickness and cross-section length of the aluminium alloy crash-box.Finally, add the optimized crash-box into the bumper of the simplified vehicle model to verify the performance, the verification shows the optimized crash-box has better energy absorption property.Based on the optimization study on the crash-box’s structure and material, this paper puts forward the crash-box prioritization scheme. After the simulation and verification, the result shows the optimized crash-box has better energy absorption performance, so this can improve the car safety on the low-speed crush and give better protection to longitudinal beam and other automobile components. The prioritization scheme has great significance not only in the automobile lightweight design but also in reducing the car maintenance cost on the low-speed crush.