CV/FEM simulation of composite and polymer processing

The control-volume finite element method (CVFEM) is the major numerical tool used for flow modeling in polymer processing because it is more user friendly and more robust than other numerical methods. The purpose of this study is to establish numerical methods based on CVFEMs in simulating composite and polymer processing. In the first part of this study, the formulation and applicability of a CVFEM for steady, two-dimensional, planar and cylindrical, incompressible fluid flows in problems with or without free surfaces has been presented. The CVFEM based on the work of Masson and Baliga was first established and successfully applied to a variety of test problems. Good agreements were obtained in all cases. This CVFEM method in conjunction with an adaptive mesh method was extended to solve polymer processing involving free surface problems. A mixed formulation of the CVFEM proposed in this study was successfully applied to creep-flow Newtonian jets without any surface tension effect.; The second part of this study focused on the analysis of the liquid composite molding (LCM) process by using both numerical and experimental methods. First, this study compares the accuracy, stability, and efficiency of the five numerical schemes of CVFEM for the convection term in simulating the liquid composite molding (LCM) process. Based on the cases studied, the mass-weighted skew upwind (MAW) scheme and the one-point upwind scheme are more robust schemes for the mold filling simulation with complicated part geometry and mesh shape. Secondly, a systematic analysis of heat transfer and resin reaction in flow through a fiber reinforcement is presented. The non-isothermal mold filling experiments with and without resin reaction are compared with those from theoretical analysis and numerical simulation. Heat transfer between the fluid and the fiber reinforcement is investigated using both one-temperature and two-temperature models with the thermal dispersion effect. Finally, an innovative approach is developed to fabricate composite parts with complicated geometry by structural reaction injection molding (SRIM). The mold filling pattern is simulated using a 3-D computer model. The simulated results compared well with the experimental results when race tracking and fiber impingement effects are considered in the model.