从聚合物粘弹性理论出发,构建了注塑制品内应力计算的蠕变模型。结合蠕变试验结果,分析聚合物注塑粘弹性行为的非线性响应,并提出在应力、温度作用下聚合物弹性模量和粘度的计算公式。在此基础上,利用有限元法对工程塑料ABS(Acrylonitrile butadiene styrene)平板注塑制件脱模前的内应力进行了模拟计算并与相关试验数据及模拟结果进行比较。结果表明该模型计算精度较高,且计算过程简便,为进一步准确预测注塑制件内应力提供了新的途径。
In the light of viscoelastic theories of polymer and relevant experimental results, a creep model for calculating the internal stress of injection molded parts is constructed. Based on the creep experimental results and theoretical analysis on the non-linear viscoelastic response of polymer, the formulas are presented to evaluate elastic modulus and viscosity of injection molding polymer. Furthermore, the internal stresses of an injection molded ABS plate are predicted by finite element method. To verify the reliability of the model, the results are compared with relevant experimental data and the data simulated by Moldflow. The results show that the calculating precision with new model is improved. And the calculating steps are simplified. It is tested that the model is an effective approach to predict the internal stresses of injection molded parts.