高分子粘弹性熔体注射成型非等温保压过程的模拟

Simulation of the Packing Stage of Viscoelastic Polymer Melt under Non Isothermal Conditions

对粘弹性熔体的注射成型非等温保压过程进行了模拟．数值计算使用有限元／有限差分的混合方法．计算结果表明，由于可压缩性，流道中的熔体能进一步流入模腔，使制品增密．保压过程是一个非等温过程，温度变化对制品性能有较大影响．由于选用了粘弹性本构方程，除了剪切应力外，模型还能预测法向应力分布．理论计算结果与商品软件ＭＯＬＤＦＬＯＷ进行了比较，压力分布吻合较好．

A theoretical model was employed to simulate the packing stage of injection molding process. Implementation of such a model is based on a hybrid finite element/finite difference method of generalized Hele Shaw flow. The simulation of a compressible viscoelastic fluid under non isothermal conditions was discussed. In addition to the distribution of pressure, temperature and velocity, the model also predicts shear stresses and normal stresses, which could be used for subsequent calculation of residual flow stresses. The theoretical result of pressure was also compared with the prediction of the commercial software MOLDFLOW, and good agreement was obtained.