Analysis and Simulation of Low-Speed Collision of Car Front Bumpers

Bumper systems are vital to improving automotive passive safety and reducing the maintenance cost in low-speed collision. Automotive companies need to develop bumpers with adequate strength, high energy absorption rate, minimum weight and least expense. To shorten the product development period and lower the development cost, four evaluation conditions were proposed to assess the behaviors of car front bumpers based on the three main low-speed collision regulations of the US Part 581, the Canadian CFVSS215 and the European ECE-R42. A finite element method was put forward to model the car front bumper and to analyze the low-speed collision performance of the bumper system. A drop hammer impact test was carried out to verify the validity of the method, and experiment results indicated the correctness of the finite element model. The dynamic response and the energy absorption parameters of the bumper system were calculated, including structural deformation, collision force and energy absorption ratio. The maximum longitudinal deformation and the energy absorption ratio were chosen as the evaluation standards to determine whether the bumper meets the collision requirement or not. The influence of beam thickness on the collision performance of the bumper was also discussed, and a two-mm-thick beam was adopted after comparison.