塑料注射成型应力与翘曲的集成模拟

针对塑料注射成型工艺的特点,提出了残余应力和翘曲变形的数值模拟方法。根据不同成型阶段特征,提出复合边界条件和假设,残余应力采用线性粘弹性模型,数值实现采用在时间上有限差分和在厚度方向分层处理的方法。翘曲变形模拟在传统的平板壳元模型基础上,提出了基于制品表面网格的改进模型,避免了使用传统板壳模型的缺陷。通过实例对比分析证明,提出的数值模拟方法能较好地预测制品应力与变形。

An integrated simulation of residual stress and warpage for plastic injection molding

A numerical study of residual stresses and warpage was undertaken according to the characteristics of plastic injection molding process. A linear thermoviscoelastic model was adopted in simulating rcsidual stresses, with multiple boundary conditions and assumptions during different stages. A Finite difference method in the time was employed in calculation with a layer discretization in the thickness direction. Warpage simulation was based on a modified flat model with surface mesh, which avoided the deficiencies of traditional flat models. Validation was carried out by comparing with application data. It was found that the residual stress and warpagc could be predicted well by the proposed simulation.