基于物质点法金属体积成形过程的仿真

Simulation of Metal Bulk Forming Based on MPM

针对传统有限元法开展金属体积成形分析过程中存在的网格畸变,以及在常规无网格法分析中存在的本质边界条件施加困难等问题,建立了基于物质点法金属体积成形过程的仿真模型。因其背景网格积分采用了有限元形函数,从而有效地解决了边界条件施加困难的问题。通过对圆柱顶镦和反向挤压等金属体积成形过程的仿真,并将仿真结果与实验和有限元结果进行了对比分析,结果显示物质点法不仅能有效地消除网格畸变,而且在金属发生大变形时其计算精度优于有限元法的计算精度。所得结论可为物质点法在弹塑性大变形分析中的应用提供指导。

Aiming at the problems that mesh distortions in finite element method（FEM）and difficulties of applying the essential boundary conditions in the traditional mesh-less method when doing the analysis of metal bulk forming process,a simulation model of metal bulk forming process was presented based on MPM.Because the shape function of the finite element method was used on the background grid nodes,MPM might solve the difficulty problems in dealing with the boundary conditions effectively.Two metal bulk forming processes（heading of cylindrical billets and backward extrusion）were performed,compared the results of experiments with those of finite element method,it is shown that MPM may eliminate the mesh distortions,and may get more accurate results than that of the finite element method when large deformations occur.The conclusions may provide guidance for the MPM to be applied in the large elastic-plastic deformation analyses.