板材多点成形过程数值模拟的研究

多点柔性成形是一种先进的板材成形技术。在多点成形过程中 ,板材的受力状态、变形特点、接触边界等与传统的冲压成形有很大的不同 ,商业软件不能有效地反应这些特点。本文给出了自主开发的板材多点成形过程数值模拟专用软件 (MPFORM)所采用的有关理论与公式 ,介绍了基于UL隐式格式的弹塑性大变形有限元方法、退化板壳有限元模型以及处理多点不连续接触边界的接触单元技术等 ,给出了球形面与马鞍面多点成形过程的MPFORM数值模拟结果

STUDY ON THE NUMERICAL SIMULATION OF MULTI-POINT FORMING PROCESS FOR SHEET METAL

The multi Point Flexible Forming(MPF) is an advanced processing technique of sheet metal.The stress state?deforming state and contact boundary, etc.of sheet in multi point forming process are very different from those in traditional stamping process.Commercial software couldn't represent these features effectively and exactly.In this paper,the theory and formulations in the special numerical software(MPFORM) which is developed independently by us for the simulation of MPF process are described.The elasto plastic large deformation finite element method based on Updated Lagrange implicit formulation,the degenerated shell element model and the method of contact element to deal with multi point,discontinuous contact interface are introduced.The simulating results calculated by MPFORM for the MPF process of sphere and saddle shape are presented finally.