Hierarchical representation and similarity assessment for reuse of sheet metal parts

Sheet metal parts are widely used in the manufacturing industry. With the number of 3D models increasing, it is essential to retrieve existing resources. Effective similarity assessment would be useful in many downstream applications, such as design reuse and manufacture process revision. We propose a hierarchical representation and similarity assessment algorithm to retrieve 3D models of sheet metal parts. Based on single-side representation extracted from solid models, flat and bent faces are recognized and clustered into groups. The morphological relationship between these two groups is then described and an attributed graph is built to store the connection between flat groups. A hierarchical representation is derived by a simplification and assembly process. This structure supports similarity assessment in different levels of detail; thus, a multiple-resolution formula is introduced to measure the total similarity. The algorithms were implemented based on a neutral standard for the exchange of product model data (STEP) format and a prototype demonstrates the application in shape search and reuse in manufacturing industry.