汽车结构耐撞性分析中的冲击接触算法

The contact-impact algorithm for crashworthiness analysis of automobile structures

汽车碰撞过程是一个典型的大变形动态接触过程 ,在汽车结构耐撞性分析研究过程中 ,除了有限单元和材料模型方面的因素外 ,接触算法在计算时间和计算精度方面起着很重要的作用 .用于大规模动态接触问题的接触搜索过程大体可分为两阶段 :全局搜索和局部搜索 .目前使用较普遍的、有影响的全局搜索算法主要包括主从面算法、单曲面算法、级域算法、位码算法及NBS算法 ;局部接触搜索算法主要有基于“点面算法”、基于“小球算法”、基于光滑曲面 (曲线 )算法三大类 .接触界面算法目前主要有拉氏乘子法和罚函数法 ,以及扰动拉氏法和扩大拉氏法 .此外 ,接触问题的并行计算也是不可忽视的研究内容 .分析接触算法的研究现状 。

It is a typical great deformed dynamic contact process for automobile impact.Contact algorithm plays an important role in the aspect of computation accuracy and cost,except the factor of finite element and material model in the crashworthiness analysis of automobile structures.Special attention is paid to the contact searching algorithms which can be divided two parts:global searching algorithms and local searching algorithms.Advantage and disadvanage are both given for wide spread algorithms respectively(master slave algorithm,single surface algorithm,territory algorithm,position code algorithm,and NBS algorithm for global searching,node surface algorithm,pinball algorithm and smooth curved surface algorithm for local searching).Else,contact interface algorithms(Lagrange multiplier method,penalty method,perturbed Lagrangian method and augmented Lagrangian method),and the parallel computing methods for the contact impact problems on the computer cluser net environment are also discussed.Analysing the present condition of contact algorithm can push forward the further researching of crashworthiness analysis of automobile structures.