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• Main Authors: Chia-Ying Chung, 鍾佳穎
• Other Authors: Jiing-Yih Lai
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/w865h6

碩士 === 國立中央大學 === 機械工程學系 === 106 === Solid meshes play an important role in finite element analysis. They affect the accuracy and efficiency of the numerical analysis and simulation. They also affect the computational time significantly. Thin shell parts commonly appear in injection molding and contain many extrusion features, such as ribs, tubes, complex supporting structure and molding. If tetrahedron meshes are employed for these features, it usually results in poor quality mesh. A common solution for this issue is decomposing these features and generating appropriate types of meshes for each of them. Conventionally, this process is done manually, which requires substantial operating time. If extrusion features on CAD models can be recognized and decomposed automatically, it could speed up the process of mesh generation. The aim of this research is to develop a feature recognition algorithm for internal extrusion features on thin shell parts, and to develop a feature decomposition algorithm to separate them from the model. In the proposed feature recognition algorithm, the inner and outer faces of a model are separated first. The relationship between extrusions is then evaluated, and the paired faces on each extrusion are determined. The recorded information is then employed for the decomposition of extrusions. An automatic decomposition algorithm was developed for simple CAD models. The quality of the meshes generated was also verified.