超薄板料多次拉深成形数值模拟关键问题处理

Study of key problems in multi-stage deep drawing numerical simulation of ultra-thin sheet

针对超薄板料多次拉深数值模拟中出现的网格翘曲和质量增大过大问题,从有限元理论基础和材料厚度的特点出发,指出薄板多次拉深成形仿真过程中应注意的几个关键技术问题:单元大小、单元法向之间夹角、单元厚度、质量缩放因子。并通过钢笔外壳多次拉深实例说明,及时修改自适应划分网格参数可以避免网格翘曲,随着网格变小要相应调整质量缩放因子以降低虚拟惯性力。

For the matter of mesh warping and mass enlargement in multi-stage drawing numerical simulation of ultrathin sheet, the reasons were analyzed in view of the finite element theory and the material thickness. The key technologies used in simulation , such as element size, the angle between element normal, element thickness and mass scaling were pointed out. Through pen shell multistage drawing, it could be realized that modifying parameters of adaptive meshing could avoid mesh warping, and with the element becoming smaller it needed to adjust the mass scaling factor in order to reduce the virtual inertia force.