Abstract: In view of the lack of correctness verification of MBD function 3D annotation in commercial CAD software at present, this paper studies the problems of 3D dimension labeling and validation inspection based on the geometric modeling core of OpenCASCADE. By extracting the geometric features of the annotated object and combining the information annotation rules, the matching between the annotated content and the annotated object is judged, and then the correctness of the annotation is judged. The hierarchical data structure is designed to store the annotation information, and the annotation information is associated with the shape elements, which avoids the repetitive annotation, and also provides the possibility for automatic extraction of product semantic information during subsequent virtual assembly, processing and manufacturing and service. The annotated information is stored in XML format, which is convenient for information transmission and access, which lays a good foundation for further research on digital twin technology.

Key words: 3D annotation, MBD, validity checking, OpenCASCADE