3D model retrieval method of mechanical parts based on B-Rep

This study proposes a boundary representation (B-Rep) based method for three-dimensional CAD model retrieval of mechanical parts. To reduce computational complexity and improve matching precision, auxiliary geometric features that do not influence the global structure such as chamfers, fillets, casting curvatures, tool withdrawal grooves and grinding wheel grooves are removed during preprocessing. The refined model is decomposed into individual surfaces, from which comprehensive geometric and topological attributes, including surface type, outer-loop and inner-loop features, area, perimeter distribution, concave and convex vertices, and adjacency relationships, are extracted. Surface-level correspondences are computed using a shape and adjacency matching strategy, and overall similarity is assessed by aggregating matched surfaces at the part level. Experimental evaluation on a representative dataset demonstrates that the method achieves high retrieval accuracy and robustness, while maintaining moderate preprocessing and computational requirements. These results indicate that the proposed approach effectively balances retrieval performance with overall development effort, offering a practical solution for efficient and reliable 3D CAD model management.