Abstract: Micro injection molding is an efficient and low cost process for the large-scale replication of thermoplastic polymer microparts.Numerical simulation in cavity filling is important to mold design and process parameters setting before mold manufacture.A meshfree-based method for solving viscosity equations was proposed to simulate the filling process of micro injection molding.The N-S governing equations were discretized by using a particle approximate method of smooth particle hydrodynamics.Some physical properties,such as velocity,pressure,and temperature were investigated in the filling process.As an example,mold cavity filling simulation for a microneedle used in biomedical application was performed,and the results were consistent with experiment.Compared with the traditional mesh method,such as three dimensional finite element method,with corresponding node or particle number and process condition,the proposed meshfree method showed advantages of higher accuracy and calculation efficiency.

Key words: micro injection molding, meshfree method, smooth particle hydrodynamics, numerical simulation

摘要： 基于无网格方法和黏性本构方程，开展微注射成型数值模拟的研究。采用光滑粒子流体动力学的粒子近似法离散N-S 控制方程组，求解速度场、压力场、温度场等物理场的变化规律。以应用于生物医学领域带有细微针头的聚合物微针为例，进行充型过程的数值模拟，模拟结果与实验结果基本一致。

关键词: 微注射成型, 无网格方法, 光滑粒子流体动力学, 数值模拟