汽车发动机罩耐撞性强度优化仿真研究

摘要

对汽车发动机罩耐撞性强度的优化,能够有效提高汽车的安全系数.对汽车发动机罩的耐撞性强度的优化,需要计算出汽车发动机罩单元节点力,得到汽车发动机罩有限单元接触力,完成发动机罩耐撞性优化.传统方法进行发动机罩材料失效参数分析,得到不同因素发动机罩材料耐撞性的影响,但忽略了得到汽车发动机罩有限单元接触力,导致优化效果不理想.提出基于Hypermesh和OptiStruct的组合优化方法对汽车发动机罩耐撞性进行分析.首先采用有限元软件Hypernesh对汽车发动机罩CAD模型进行网格划分,建立汽车发动机罩各结构特征的碰撞有限元模型,求解汽车运动系统的速度和位移,计算出汽车发动机罩单元节点力和节点力矩,计算汽车发动机罩有限单元接触力,完成汽车发动机罩耐撞性强度优化.仿真证明,所提方法汽车发动机罩耐撞性强度优化分析精度较高,且鲁棒性较强.%An analysis method for crashworthiness of automobile engine hood is proposed based on combinatorial optimization method of Hypermesh and OptiStruct.The finite element collision model for structural characteristic of automobile engine hood is establish by using finite element software Hypemesh,and then speed and displacement of vehicle motion system is solved to calculate element nodal force,joint torque and contact force of finite element of automobile engine hood.At last,crashworthiness strength optimization of automobile engine hood is completed.The simulation results show that the proposed method has high analysis accuracy for crashworthiness strength of automobile engine hood and stronger robustness.