| 摘要: | 在射出成型產業中，產品研發與設計過程中需要進行品質控制與修正，除了經驗法則外，使用CAE（Computer aided engineering）軟體進行分析是一種常見的方法。模流分析（Mold flow analysis）軟體在此產業中不可或缺，模流分析是一種有限元素分析（Finite element method），因此在進行分析之前，需要將CAD（Computer aided design）模型進行網格化，以提供網格資料供軟體計算。非結構網格有許多種形式，其中，最常見的是邊界層網格（Boundary layer mesh）和四面體網格（Tetrahedron）。然而，這兩種網格排列不規則且網格數量較多，因此為了提高網格品質和準確度，使用結構化的六面體網格（Hexahedron）效果較佳。結構化網格通常需要對CAD模型進行切割後才能進行，由於CAD模型有進行切割，結構化網格具有規則排列和對稱的特性，且在相同網格尺寸下，結構化網格的體積較四面體網格大，可以大幅減少網格數量。故模流分析時，使用結構化網格可以提高精準度和效率。然而，由於需要進行切割，不同輪廓可能需要不同的切割方式。因此，本研究將CAD模型經過薄殼體積分解後，將其分解區塊結果之輪廓，開發分解演算法，由輪廓分解結果經過撒點等步驟後，建立此多邊形的點資料，最後實現多邊形輪廓的結構化網格。;In the injection molding industry, quality control and correction are required in the process of product development and design. In addition to rules of thumb, using Computer aided engineering software for analysis is a common method. Mold flow analysis software is indispensable in this industry. Mold flow analysis is a Finite element method, so before analysis, Computer aided design model needs to be gridded, to provide grid data for software calculation. There are many forms of unstructured grids, among which the most common are Boundary layer mesh and Tetrahedron mesh. However, the arrangement of these two grids is irregular and the number of grids is large, so in order to improve the quality and accuracy of the grid, it is better to use the structured Hexahedron grid. The structured grid usually needs to be cut after the CAD model is cut. Because the CAD model is cut, the structured grid has the characteristics of regular arrangement and symmetry, and under the same grid size, the volume of the structured grid is smaller than that of four sides. The volume mesh is large, which can greatly reduce the number of meshes. Therefore, in mold flow analysis, the use of structured grid can improve accuracy and efficiency. However, due to the cutting required, different profiles may require different cutting methods. Therefore, in this study, after the CAD model is decomposed by thin shell integration, the contour of the decomposed block result is taken, and the decomposition algorithm is developed. After the contour decomposition result is scattered through steps such as points, the point data of the polygon is established, and finally the polygon contour is realized. structured grid. |
