聚合物注塑成型内应力数值计算的非线性模型

Non-linear model for calculating internal stress of injection-molded polymers

为了提高注塑内应力计算的可靠性,利用粘弹性力学理论建立了新的注塑制品内应力计算的四元件串联力学模型,并推导了其瞬态粘弹性响应的非线性本构方程.通过求解流动及保压控制方程,得到内应力计算所需的温度场和压力场,利用回归分析得到了聚合物弹性模量和粘壶系数的计算公式.用新模型对PS平板注塑制件脱模前的内应力进行了模拟计算.计算结果与固体高聚物的结构和力学性能的相关研究结论相一致.

In order to improve the reliability of calculation for injection molding internal stresses,a new four-element mechanical model in series was proposed by the theory about viscoelastic mechanics.Its non-linear constitutive equitation was derived to describe dynamic viscoelastic behavior of the polymers.The temperature and packing pressure,used as input of calculating the internal stresses,were obtained by solving the governing equations.The models of calculating elastic modulus and viscosity for moldings were built with regression method.The internal stresses of an injection molded polystyrene plate were simulated with the new models.The results agree well with published researching conclusions about the structure and mechanical properties of polymers,which shows the reliability of the established model.