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采用GLS(Galerkin/least-squares)、SUPG(Streamline upwind/Petrov-Galerkin)、GGLS(Galerkin gradientleast-squares)等方法对塑料注射成型过程进行三维数值模拟以获取速度、压力与温度场,基于剪切应力引起分子链取向并导致平衡熔点升高的假设推导了非等温剪切诱导结晶动力学模型,引入了注射成型过程与结晶相互作用的计算模型,建立了三维流场中结晶过程的稳定有限元计算模型.不同成型工艺条件下的数值算例表明,充模过程中一般注射时间较短,熔体温度较高,塑料结晶量很小,可以忽略不计;工艺条件决定最终制品的结晶分布,可以通过改变工艺条件获得所需要的结晶形态分布,结晶过程释放的潜热对充模后冷却过程中的温度场具有重要影响.
The Galerkin / least-squares (GLS), SUPG (Streamline upwind / Petrov-Galerkin), GGLS (Galerkin gradientleast-squares) and other methods were used to simulate the process of plastic injection molding to obtain velocity, pressure and temperature fields. The model of non-isothermal shear-induced crystallization kinetics was deduced on the assumption that the molecular orientation caused by stress and the equilibrium melting point increased. The calculation model of the interaction between injection molding process and crystallization was introduced, and the stable finite element Numerical simulation results show that the injection time is short, the melt temperature is high, the amount of plastic crystallization is very small and can be neglected. The process conditions determine the crystal distribution of the final product, By changing the process conditions to obtain the required crystal morphology distribution, the latent heat released during the crystallization process has an important effect on the temperature field during the cooling process after filling.