基于ALE描述的压缩流动三维粘弹性数值模拟

发布时间：2018-06-08 05:14

  本文选题：ALE + 注压成型　； 参考：《应用力学学报》2016年03期

【摘要】：塑料熔体压缩流动中在主流动平面及厚度方向均有速度变化,结合了剪切和拉伸两种流动特征。为了准确描述和模拟塑料熔体的压缩流动,本文基于粘弹性及ALE原理建立了熔体三维流动理论模型,构造了有限元求解的变分方程。为了避免整体求解计算量大、稳定性差的缺陷,提出了两重迭代解耦合算法分别求解耦合的连续方程、动量方程、本构方程、能量方程,开发了模拟程序。开展了等厚度板及变厚度板的注压成型实验及相应的数值模拟,结果表明:压缩过程中出现压力变化小于4.57%的平台现象;温度呈指数规律下降;塑料入口、流动末端第一法向应力差比平均值分别高1.73MPa、0.87MPa,变厚度区域第一法向应力差比平均值高1.16MPa。本文提出的理论模型和数值算法能够较好地表征压缩过程中熔体的压力、温度变化、应力演化。
[Abstract]:In the compression flow of plastic melt, the velocity changes in both the main moving plane and the thickness direction, and the shear and tensile flow characteristics are combined. In order to accurately describe and simulate the compression flow of plastic melt, a three-dimensional melt flow model is established based on viscoelasticity and ale principle, and a variational equation for finite element solution is constructed. In order to avoid the defects of large computation and poor stability, a double iterative decoupling algorithm is proposed to solve the coupled continuous equation, momentum equation, constitutive equation and energy equation respectively, and a simulation program is developed. The experiment and numerical simulation of injection molding of equal thickness plate and variable thickness plate are carried out. The results show that the pressure change is less than 4.57% during compression, the temperature decreases exponentially, the plastic inlet, and the pressure change is less than 4.57%. The first normal stress difference at the end of the flow is 1.73 MPA / 0.87 MPa higher than the average value, and the first normal stress difference in the variable thickness region is 1.16 MPA higher than the average value. The theoretical model and numerical algorithm presented in this paper can well characterize the pressure, temperature change and stress evolution of the melt during compression.
【作者单位】： 郑州大学橡塑模具国家工程研究中心;北京航空材料研究院;
【基金】：国家自然科学基金(11272291) 国家重点基础研究发展计划(973)项目(2012CB025900) 河南省科技厅基础研究(142300410029)
【分类号】：O357
，

本文编号：1994652