板料变形中两种摩擦模型的比较

本文应用刚塑性有限元方法，分别采用修正的常剪应力摩擦模型和库仑摩擦模型，对板料在半球形冲头下的拉胀变形和在平底圆柱冲头下的拉延变形过程进行计算，并上述两种摩擦模型的作用机制以及它们板料塑成形过程的影响进行了研究。通过分析、比较与实验验证，表明库仑模型比常剪应力模型更为适合板料成形过程模拟的摩擦描述。

A Comparison of Two Friction Models in Sheet Metal Forming

Implementing modified constant shear condition and coulomb friction condition respectively, the hemispherical punch stretching and flat cylindrical deep-drawing processes of sheet metal are simulated by rigid plastic FEM. Analysis is made about the working mechanism of the two friction models, and their effect on the deforming processes of sheet metal is studied. A comparison of calculation results with the experimental data is also made concerning the distribution of thickness strain as well as the curve of punch load/punch stroke.It is finally recommended that the use of coulomb friction model is more reasonable in process simulation of sheet metal formation.