Research and development of MBD model definition based on STEP AP242

A MBD information expression method based on STEP AP242 was proposed for several problems, such as the collaborative problem between heterogeneous hardware and software in product development process, the non-standardized and non-machine-readable problem of MBD model. Take the MBD model constructed by CATIA system as research object; the relevant information in MBD model was extracted using CATIA CAA (component application architecture) customized development technology, and the STEP standard neutral files were generated according to STEP AP242 standard. Firstly, introduce the development history of STEP AP242 standard and the expression mode of geometric dimension & tolerance (GD&T), namely Presentation mode and Representation mode. Then, give the expressions and extraction methods of MBD model annotation information, the association between annotation information and geometric information based on geometric element categories, such as faces and edges. Finally, the expression and conversion with STEP AP242 standard about MBD model information are realized by EXPRESS language, and the feasibility and effectiveness of the method was verified by two tools, STEP File Analyzer and STEP-NC Machine. As results, sematic Geometric Dimension & Tolerance of MBD model is achieved.