注射过程中残余应力演变的模拟与分析

Simulation and Analysis of Residual Stress Evolution in Injection Molding

采用线性黏弹性模型,模拟计算了平板形状制品残余应力在壁厚方向和流动方向上的分布及其在成型中的变化过程。根据模拟结果,深入讨论了注射成型过程中残余应力的形成机理和演变情况。结果表明:脱模时制品表层有着较大的拉应力,表层以下存在着一个应力低谷,在制品中心区域存在着抛物线形的拉应力分布;残余应力沿壁厚分布的形状在流动方向上基本相同,但是流动末端的应力值稍大于流动入口处。

Distribution and history of residual stress in plaque-like geometries are simulated based on linear viscoelastic model. It was found that there is a high tensile stress on the surface due to mold stripping, a compressive peak value close to the surface, and a parabolic tensile peak at the core region. Residual stress distribution along the thickness is almost the same in the flow path and the stress value near the end is a little higher than that near the gate.