板材在模具圆角处的接触状态研究

A Study of Contact between Strip and Die Shoulder

以数值模拟为手段对板材在拉力下通过模具圆角时的接触状态进行了研究,分析了板材与模具圆角间的接触特点,通过大量对比计算给出了接触状态与圆角大小及受力状态间的关系。指出一般情况下,板材与模具圆角间的接触压力呈两端高、中间低的分布趋势;两者间依拉力及圆角半径的不同存在4种典型的接触状态。并在此基础上对欧拉公式进行了误差分析及修正。

In the paper, the contact and frictionstates of a strip at die shoulder is studied by FEM simula-tion when strip is pulled through the shoulder withstretching force. The characteristics of contact state areanalyzed. The relations between contact states and shoul-der radius, stretching force are investigated by a largenumber of calculations. The simulation results show thatthere are four typical styles of contact pressure distribu-tion, and generally the distribution of contact pressure isnonlinear, higher pressure exists at the two ends of con-tact area and lower pressure at middle. Then the frictioncalculating errors between Euler equation and simulationis analyzed. And it is pointed out that usually the Euler e-quation has enough precision for the requirementa of engi-neering calculations. But if the stretching force and radiusof die shoulder are smaller, the Euler equation will pro-duce bigger calculating errors. At the end, an modifiedEuler equation is given out.