A unified simulation of the filling and postfilling stages in injection molding. Part I: Formulation
A unified simulation of the filling and postfilling stages in injection molding. Part I: Formulation
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DOI：
10.1002/pen.760310210
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发表时间：
1991
影响因子：
3.2
通讯作者：
H. Chiang;C. A. Hieber;K. K. Wang-K.
中科院分区：
文献类型：
--
作者：
H. Chiang;C. A. Hieber;K. K. Wang-K.
本研究采用一个统一的理论模型来模拟注射成型过程的填充和后填充阶段。这样一个模型的实现是基于混合有限元/有限差分数值解的广义Hele-Shaw流动的可压缩粘性流体在非等温条件下。聚合物材料的剪切粘度由用于剪切速率依赖性的Cross模型和用于温度和压力依赖性的WLF型函数形式表示，而比容由双域Tait方程建模。该分析还处理作为温度的函数的聚合物的可变比热和热导率。变厚度的复杂薄零件可以通过平面三角形有限元进行建模和离散化，这些有限元在三维空间中可以具有任意方向，而零件中的流道和可能的圆销或凸台则表示为一维圆管单元。一个控制体积计划，导致自动熔体前沿的进步，在空腔填充阶段。
This study employs a unified theoretical model to simulate the filling and postfilling stages of the injection-molding process. Implementation of such a model is based on a hybrid finite-element/finite-difference numerical solution of the generalized Hele-Shaw flow of a compressible viscous fluid under nonisothermal conditions. The shear viscosity of the polymeric material is represented by a Cross model for the shear-rate dependence and a WLF-type functional form for the temperature and pressure dependence, whereas the specific volume is modeled in terms of a double-domain Tait equation. The analysis also handles variable specific heat and thermal conductivity of the polymer as a function of temperature. Complex thin parts of variable thickness can be modeled and discretized by flat, triangular finite elements which may have arbitrary orientation in three-dimensional space, whereas runners and possible round pins or bosses in the part are represented as one-dimensional circular-tube elements. A control-volume scheme is employed that leads to automatic melt-front advancement during the cavity-filling stage.