Applying the topological relationships of form features to retrieve part files from a CAD system

The efficient retrieval of stored CAD files is an area that has received significant attention in recent years. Several Product Data Management products have been developed, most of which are based on the use of coding concepts to retrieve designs. However, the limited number of codes that can be used limits the flexibility of part shape representation and also versatility in retrieving existing drawings. In this paper, an integrated approach using topological relationships among form features as the search indices is proposed. The use of a feature adjacency graph and also a feature topological relation graph that acts as the interface enables this approach to translate the feature-based B-Rep model of a part that is stored in the CAD system into topological relationships that are stored in a relational database. In addition, five types of queries based on topological relationships are used to aid the retrieval of designs. The proposed technique for design retrieval is more convenient than traditional coding based methods.