汽车发动机罩的轻量化设计

Lightweight Design of Automobile Engine Hood

文章基于更换轻质材料(铝合金),并结合多目标优化对发动机罩进行轻量化。对发动机罩的扭转刚度、弯曲刚度、强度、模态、行人保护性能进行了分析。以刚强度及模态性能为约束,行人保护性能和发罩质量为目标,在Isight软件中搭建多目标优化流程,经过NSGA-Ⅱ算法迭代优化得到最优解。结果表明:优化后的发罩相比原发动机罩,刚度性能与行人保护性能有小幅提升,质量减轻39.85%,达到了很好的轻量化效果。该方法可为发动机罩轻量化设计提供一定的参考。

The paper is based on replacing lightweight material(aluminum alloy)and combined with multi-objective optimization.The torsional stiffness,bending stiffness,strength,mode and pedestrian protection performance are analyzed.With stiffness strength and modal performance as the constraint,pedestrian protection performance and hood quality as the goal,a multi-objective optimization process is built in Isight software,and the optimal solution is obtained through iterative optimization of the NSGA-H algorithm.The results show that compared with the original hood,the optimized hood was slightly improved with pedestrian protection performance,and the quality was reduced by 39.85%,which achieved a good lightweight effect.The method can provide some reference for lightweight design of engine hood.