等径通道挤压过程三维有限元模拟

3D Finite element simulation of equal channel angular pressing

利用三维有限元模型对等径通道挤压过程中变形分布的不均匀性进行了模拟,通过对不同摩擦系数下截面等效塑性应变分布比较发现:沿三个方向截面上的变形分布都不是均匀的,这说明二维有限元模型不能真实模拟等径通道挤压过程中试样中的变形分布。此外,摩擦对等效塑性应变分布及挤压力的影响较大,截面变形不均匀参数和最大等效塑性应变出现的位置随摩擦系数的增大而变化。压力-位移曲线的变化可以结合试样的变形过程来解释。

In this paper, a three-dimensional finite element model is used to analyze the deformation inhomogeneity during a single pass of equal channel angular pressing（ECAP）. The equivalent plastic strains under different friction conditions are compared. It is found that the equivalent plastic strain varies along three directions, which indicates 2D finite element model is unable to perfectly simulate the deformation distribution during ECAP process. The influence of friction on equivalent plastic strain and pressure is also found remarkable. The deformation inhomogeneity indexes and the location of maximum equivalent plastic strain are varied with the increasing friction coefficient. The different stages presented in the pressure versus displacement curves are associated with those in specimen deformation.