Development of Chamfer Recognition Technology for CAD Model

• Main Authors: Himawan Wibhisana, 何馬維
• Other Authors: Jiing-Yih Lai
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/p8z3vp

碩士 === 國立中央大學 === 機械工程學系 === 105 === In finite element analysis, mesh generation is an indispensable operation. However, one of the problems encountered when converting Computer-Aided Design (CAD) models into meshes is that CAD models often feature a large number of faces, many of which are transition faces. In the mesh generating process, poor meshes can easily be formed around the transition faces, including blend faces and chamfers. The mesh size near these entities is usually smaller han that of adjacent faces, resulting in poor analysis results. In some finite element analysis, it might be necessary to suppress such tiny transition faces. However, they should be recognized first. The purpose of this study is to develop an algorithm to recognize chamfers on a CAD model based on the understanding of a boundary representation (B-rep) model. It includes the following main operations: input B-rep model, identification of candidate chamfers, methods to classify candidate chamfers, and output chamfer data. Three types of chamfers can be recognized by the proposed method: plane chamfer, vertex blend chamfer and surface chamfer. Fifty CAD models are presented to demonstrate the feasibility of the proposed chamfer recognition algorithm.