The paper presents an engineering environment called the Feature Solid Modelling Tool ( FSMT). In contrast to the common approach of simply attaching manufacturing information to existing geometric models, the feature definition in the FSMT has been greatly augmented. A geometry is always associated with the knowledge of applying it. The knowledge represents the theory and methodology of design and manufacturing, and a CAD/CAM integration strategy. Generalized sweeping has been developed as a unified method for defining various features. Through the development of a dual representation schema of a CSG index and a B-rep index, attributes such as tolerance and roughness can be conveniently assigned to individual surfaces through the CSG model or the B-rep model. The CSG model and the B-rep model are easily accessible, and the underlying consistency and integrity are guaranteed. The feature definition also provides a sound mechanism for mapping into applications such as FEM-mesh generation, process planning and NC programming. As a result, feature information is directly available to downstream activities, and feature extraction or recognition is no longer needed. The integration of CAD and CaM is accomplished to a greater degree. A prototype system has been developed.
solid modelling,features, sweeping, CAO/CAM, concurrent engineering
It is generally agreed that more than 70-80% of the total cost of a product is determined at the design stage. Aimed