方盒形件拉深成形无网格法模拟  

Numerical Simulation of Square Box Part Deep Drawing Process by Using Mesh-free

作　　者：刘红生[1] 邢忠文[1] 杨玉英[2] 

机构地区：[1]哈尔滨工业大学机电工程学院,哈尔滨150001 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《机械工程学报》2010年第4期48-53,共6页Journal of Mechanical Engineering

基　　金：国家博士后基金(20080440846);哈尔滨工业大学优秀青年教师培养计划(HITQNJS2009.014)资助项目

摘　　要：针对板材冲压成形有限元模拟存在的不足,采用一种新的数值方法——无网格法对方盒形件拉深成形进行数值模拟研究。建立基于无网格法的板材冲压成形力学控制方程。采用材料形函数避免影响域和形函数的频繁更新。通过改造无网格形函数获得动可容形函数,该形函数具有插值性,通过对全域内的节点形函数进行重新构造,可精确施加复杂问题的本征边界条件。利用模具上分布的节点建立矩阵,利用矩阵的特性可实现接触搜索。在此基础上,为提高接触搜索效率,提出建立稀疏'矩阵'数据结构加快接触搜索。编写板材冲压成形无网格模拟程序,实现方盒形件拉深成形无网格法模拟。通过盒形件冲压成形无网格数值模拟考察压边力对盒形件冲压成形过程的影响,获得厚度分布和应力应变分布,通过数值模拟结果与试验结果的比较,表明采用无网格法模拟板材冲压成形是有效的。A new type of numerical method called mesh-free method is presented to implement the simulation of square box part deep drawing in view of the drawback of finite element method.Mechanics equations for dominating the sheet metal forming process based on mesh-free reproducing kernel particle method are developed.The material shape function is adopted to avoid the frequent updates of shape function and influence domain.To impose the essential boundary conditions exactly,mesh-free shape function is re-constructed and the modified shape function called kinematically admissible shape function is interpolatory.The all shape functions associated with nodes within the whole domain are re-constructed in order to enforce the complex essential boundary conditions expediently and exactly.The nodes distributed in the die are used to construct a matrix owning the characteristic which can be used to search the slave node being in contact with the die.Furthermore a data structure called ＂sparse matrix＂ is proposed to accelerate the contact searching.The program for simulating the sheet metal forming process is set up,and the mesh-free simulations of deep drawing for the square box part are implemented.The influence of blank holder force on the deep drawing is investigated,and the distributions of thickness,stress and strain are obtained by meshless numerical simulations.The comparison of numerical results with experimental results shows the effectiveness of using mesh-free method to simulate sheet metal forming.

关 键 词：数值模拟 有限元法 冲压成形 无网格法 

分 类 号：TG316[金属学及工艺—金属压力加工]