Studies On Inversion Of Injection Velocity In Injection Molding Based On CAE Technology

In the precision injection-molded field, it has been a very important method to control the final quality of the parts by the filling processing parameters. In the filling processing of injection molding, Melt-Front-Velocity (MFV) is one of the most significant factors influencing the final part quality and dimensions. How to control MFV is worth of further study. In this paper, we develop an inversion model and solve it by regularization method. The feasibility of this method is justified with numerical computations.Main contents of this dissertation are as follows:In chapter 1, the background of this dissertation is introduced. The history and current status of CAE technology and processing optimization are illustrated. The fundamental conception of inverse problems is introduced and some existing methods for solving inverse problems are surveyed. Main works in the dissertation are summarized.In chapter 2, through studying the flowing behavior of melt in cavity, the pressure and temperature governing equations for filling stage are obtained based on reasonable assumption and simplification. A hybrid finite-element/finite-difference/control-volume method is employed to solve these equations.In chapter 3, the influence of MFV on the final part quality and dimensions is analyzed, and the problem is shown. Corresponding inversion model of flow rates is given.In chapter 4, the Bregman regularization is introduced to modify the model. D-functions are employed as the regularization functions, and a homotopy method is employed to widen the convergence region of the method.In chapter 5, the algorithmic implementation of Bregman regularization method and some numerical examples are given.It is shown that the method of inverse problem integrated numerical simulation is feasible to obtain the optimum injection velocity.This thesis is supported by the National Natural Science Foundation of China under Grant 10590354,10572031.