中文摘要：

摘要对半结晶聚合物注射成型过程及其结晶过程进行偶合模拟，分析了二者的相互影响。具体是在注射成型考虑结晶动力学效应，分别在本构方程、能量方程及材料物性参数方程中引入反映结晶效应的参数；同时在结晶动力学计算中考虑流动诱导效应，从能量的角度提出并使用修正的动力学模型，用材料流动过程的耗散能表征流动对结晶的影响。通过对等规聚丙烯（iPP）和聚对苯二甲酸乙二醇酯（PET）两种半结晶聚合物注射过程模拟结果的分析比较，证实成型过程具有加速结晶的作用。同时，材料的结晶也对注射成型加工过程，尤其是保压与冷却过程的温度场分布有较大的影响。

英文摘要：

The crystallization of semi-crystalline polymers is often influenced by processing, and their crystallization may also influence the processing simultaneously. The present study is an attempt to simulate the two aspects of the injection moldings of semi-crystalline polymers. Firstly, by assuming that the effect of flow on crystallization is only in terms of increasing the crystallization rate constant, an approach based on the quiescent-state crystallization equation is proposed to develop the qualitative description of crystallization phenomena under non-isothermal flow occurring in injection molding processing. The energy of dissipation, the work of stress occurring in the injection molding operations, is regarded as the main parameter of the equation of the crystallization rate. Secondly, the proposed modeling of the flow-induced crystallization kinetics is directly applied to predict the development of the crystallinity during the injection moldings of two semi-crystalline polymers： fast-crystallizing polymer isotactic polypropylene （iPP） and slow-crystallizing polymer polyethylene terephthalate （PET）. In the prediction, the kinetics of crystallization is considered in the simulateion of three stages：filling, packing and cooling of injection molding, and the parameter reflected the effect of crystallization is included in the equation of the relationship of stress and strain, along with the equations of continuity, momentum and energy conservation, the equation of state and other parameters of materials; the flow-induced effect is also considered and the energy of dissipation is regarded as the main parameter in computing the kinetics of crystallization. Finally, the conclusion can be drawn after the simulated data for the development of crystallinity and the distribution of temperature and pressure field in the moldings are compared and analyzed. Although the results show the kinetics of flow-induced crystallization has little influence during the process of computing the distribution of the pres