Lightweight design of automotive front end material-structure based on frontal collision 2020-01-0204
The front end structure is an important role in protecting the vehicle and passengers from harm during the collision. Increasing its protective capacity can be achieved by increasing the thickness or replacing high-strength materials. Most of the current research is analyzed separately from these two aspects. This paper proposes a multi-objective optimization method based on agent model, which combines material and thickness selection. First, the optimized components are determined based on the 100% frontal collision simulation results. Secondly, six thicknesses and four materials of the front part of the vehicle body are selected as design variables to construct a material-structure integrated multi-objective optimization model. Taking the total mass and energy absorption of the research object as the optimization target, the B-pillar acceleration and the maximum intrusion of the dash panel are used as constraints, using the radial basis (RBF) proxy model and the second generation non-dominated genetic algorithm (NSGA-II) for lightweight design, the Pareto solution set is obtained, This optimization method can select the best material and component thickness combination scheme. Finally, by comparing the initial design with the optimized design, it was found that the body stiffness and modal values did not decrease significantly.The results show that the selected parts are reduced by 16.2%; the total energy absorption is increased by 5.6%; the intrusion in the dash is reduced by 8.9%; and the peak acceleration of the B-pillar is reduced by 39.2%.The material-structure integration optimization method is an effective method to solve the contradiction between lightweight and crashworthiness.