(An) efficient analysis of resin transfer molding process using eXtended finite element method

다국어 초록 (Multilingual Abstract)

Numerical simulation for Resin Transfer Molding (RTM) manufacturing process is attempted by using the eXtended Finite Element Method (XFEM) combined with the level set method. XFEM allows to obtaining a good numerical precision of the resin pressure near the resin flow front, where the gradient of the pressure is discontinuous. The enriched shape functions of XFEM are derived by using the level set values so as to correctly describe these shape functions with the resin flow front. In addition, the level set method is used to transport the resin flow front at each time step during the mold filling. The level set values are calculated by an implicit characteristic Galerkin FEM. The multi-frontal solver of IPSAP is adopted to solve the system. This work is validated by comparing the analysis results with analytic solutions.
Moreover, the localization of XFEM and level set method is proposed to increase the computing efficiency. The computation domain is reduced to the small region near the resin flow fronts. Therefore, the total computing quantity is minimized by the localization. The efficiency test is made with simple channel and radial flow models. The localization gives notable reduction of the computing time
Several application examples are analyzed to demonstrate ability of this study. The merging and separating of the flow fronts describes through the first analysis. In addition, the race tracking effect and macro void formation during RTM process are simulated. The wind turbine blade are also used to analyze its mold filling during RTM process. Finally, the proposed study is realized with Graphic User Interface (GUI) tool for pre/post-processing of the simulation.

목차 (Table of Contents)

• Chapter 1. Introduction
• 1.1. Overview
• 1.2. Literature Review
• 1.3. Scope of Research
• 1.4. Summary
• Chapter 2. Numerical Methods
• 2.1. Conventional Approaches
• 2.2. XFEM and Level Set Method
• Chapter 3. Analysis of RTM Process
• 3.1. Modeling
• 3.2. Formulation
• 3.3. Computing Procedures
• 3.4.Validation
• 3.4.1. Pressure Calculation
• 3.4.2. Transport of Flow Front
• 3.4.3. Comparison with Analytic Result
• Chapter 4. Efficiency of Localization
• 4.1. Level Set Method
• 4.2. XFEM
• 4.3. Efficiency Test
• Chapter 5. Applications
• 5.1. Plate with Complex Edge
• 5.2. Thin and Complex Shape Structure
• 5.2.1 Race Tracking Effect
• 5.2.2 Macro Void Formation
• 5.3. Wind Turbine Blade
• 5.4. Diamond/RTM
• Chapter 6. Conclusions
• Reference
• Appendix A. Multi-frontal solver of IPSAP
• Appendix B. Key-points of cross-sections for the composite wind turbine blade model
• Appendix C. Introduction to Parallel Computing
• 초 록