多点成形中弹性垫变形及其对成形结果影响的数值分析

Numerical analysis of the deformation of elastic cushion and its effect on the forming results in MPF of sheet metal

多点成形过程中的弹性垫技术是抑制压痕的有效方法,但是弹性垫的使用对成形件的形状也有影响。为得到精确的成形件,在成形面造型时必须基于弹性垫的变形对基本体群成形面进行修正。文章对采用不同参数的弹性垫的球面与马鞍面成形件的多点成形过程进行了系统的数值模拟研究,分析了不同参数的弹性垫的不均匀变形及其对成形结果的影响,找出了影响成形件精度的主要原因,为基本体群成形面的补偿提供了依据。

Elastic cushion is usually used to suppress dimpling in the MPF process and its effect is obvious, but it also affects the precision of forming shape. To obtain the exact object shape, the forming surface of MPF must be corrected based on the deformation of elastic cushion. The MPF process of sphere and saddle parts with different parameters of elastic cushion are systemicly simulated and studied in the paper, and at the same time the nonuniform deformation of elastic cushion and its influence on the forming results are analyzed. Through the numerical analysis of the deformation of elastic cushion, the main reasons affecting the shape precision are found and the criterion is provided to modify the forming surface of element group.