板材分段多点成形中局部剧烈塑性变形的研究

Study on Local Severe Plastic Deformation in Sectional Multi-point Forming for Sheet Metals

局部剧烈塑性变形是分段多点成形中特有的一种缺陷,对其进行深入的研究有利于分段多点成形技术的进一步实用化。本文以圆柱形工件为例,对分段多点成形过程进行数值模拟,详细分析了局部剧烈塑性变形的产生机理,并采用非均匀有理B样条曲面(NURBS)方法,进行过渡区的协调设计来抑制局部剧烈塑性变形的产生,实验证明这种方法能够显著提高工件的成形质量。

The local severe plastic deformation is a specific defect in sectional multi-point forming, so the deep study on it is of benefit to apply in practice further.In this text, taking cylinder workpiece as an example to simulate the process of sectional multi-point forming, the generation of local severe plastic deformation has been discussed in details and the method of NURBS has been adopted to design the shape of transition region to suppress the generation of local severe plastic deformation.Experiment showed that the method can increase remarkably the quality of workpiece.