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Interpreting the semantics of GD&T specifications of a product for tolerance analysis



Mehmet I. Sarigecilia, Utpal Roy, Sudarsan Rachuri


The representation and management of product information in its life cycle requires standardized data exchange protocols. Standard for exchange of product model data (STEP) is such a standard that has been used widely by the industries. The information language used for STEP is EXPRESS. Even though EXPRESS language is capable of developing well defined and syntactically correct product models, the semantics of product data are represented implicitly. Hence, it is difficult to interpret the semantics of data for different product life cycle phases for different application domains. OntoSTEP, developed at NIST, provides semantically enriched product models in OWL. In this paper, we would like to present how to interpret the GD & T specifications in STEP for tolerance analysis by utilizing OntoSTEP. This process requires (1) the development of the tolerance analysis oriented information model in EXPRESS, (2) combine this model with STEP product model, (3) translate the combined model in OWL and (4) define SWRL rules to map the GD & T specifications to the specifications needed for tolerance analysis. This study will help users interpret the GD & T specifications of a product differently as it may be required in different phases of the product's life cycle.
Computer Aided Design


Product modeling, STEP, EXPRESS, OWL, Semantic, GD & T, Tolerance analysis


Sarigecilia, M. , Roy, U. and Rachuri, S. (2014), Interpreting the semantics of GD&T specifications of a product for tolerance analysis, Computer Aided Design, [online], (Accessed May 27, 2024)


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Created February 1, 2014, Updated December 9, 2022