Classifying and recognizing face types of thin-shell models for volume decomposition in CAE analysis

Abstract

Volume decomposition aims to split a computer-aided design (CAD) model into sub-volumes that can be meshed with existing hexahedral mesh generation algorithms. The possibility of making automatic decomposition has been investigated, but the challenge remains whenever a CAD model has many extrusion features. Therefore, we propose an approach for separating extrusion features from the main body of a thin-shell model by assigning different face types. In addition, a novel method for classifying thin-shell models into regular and irregular wall types is introduced. This study mainly focuses on the type of irregular wall and divides the face-type recognition algorithm into the following four steps: separation of inner and outer regions, classification of regular and irregular-wall types, further classification of irregular-wall types, and assigning face types on each sub-type of irregular walls. As a result, a set of attributes that are usable for decomposition derivation is available for each face on the model. To verify the feasibility of the proposed method, several realistic thin-shell models are employed to demonstrate the face types recognized. In addition, the application of the face types obtained in volume decomposition is demonstrated.