A scheme for functional tolerancing: A product family in 3D CAD system

Abstract: To meet the need for product variety, many companies are shifting from a mass-production mode to mass customization, which demands quick response to the needs of individual customers with high quality and low costs. The multifunctional nature of mechanical components necessitates that a designer redesign them each time when a component’s function changes. The functional Geometric Dimensioning & Tolerancing (GD & T) specification, also called functional tolerancing, must be updated for each component. Currently, this is done by humans, and thus can be very time-consuming and error-prone. Functional tolerancing is one of the main obstacles to practical mechanical product family modeling. In this paper, a graph-based functional tolerancing scheme in 3D CAD is proposed. In the scheme, a product is generated by applying production rules to the graph of the base product, following customers’ or manufacturing engineers’ requirements. Functional tolerancing of each component of a product in the family is formulated as a non-linear constrained optimization (or cost minimization) process. Certain critical aspects of the scheme have been implemented in SolidWorks®, by using its Application Programming Interface (API) and C++. LEDA® and MATLAB® have been used to solve the graph and optimization problems.

How to cite this paper

 Wang, H & Thamma, R. (2012). A scheme for functional tolerancing: A product family in 3D CAD system.International Journal of Industrial Engineering Computations , 3(1), 81-92.

Refrences

Anselmetti, B., Thiebaut, F., & Mawussi, B. (2002). Functional Tolerancing Based on the Influence of Contacts. APSE 2002 Summer Topical Meeting on Tolerance Modeling and Analysis. Charlotte, North Carolina. CD ROM. 15-16 July 2002.

Clement, A., Valade C., & Rivière A. (1996). The TTRSs: 13 oriented constraints for dimensioning, tolerancing and inspection. Proceedings of the Advanced Mathematical Tools in Metrology III Conference. Berlin. September, 25-28.

Kandikjan, T., Shah, J.J., & Davidson, J.K. (2001). A mechanism for validating dimensioning and tolerancing schemes in CAD systems. Computer-Aided Design, 33, 721-737.

Linares, J. M. (2002). Synthesis of tolerancing by functional group. Journal of Manufacturing Systems, 21(4), 260-275.

MacDuffie, J. P., Sethuraman, K., & Fisher, M. L. (1996). Product Variety and Manufacturing Performance: Evidence from the International Automotive Assembly Plant Study. Management Science, 42, 350-369.

Martin, M. V., & Ishii, K. (1996). Design For Variety: A Methodology for understanding the Costs of product proliferation. ASME Design Engineering Technical Conferences, Irvine, CA. 96-DETC/DTM-1610.

Rothwell, R., & Gardiner, P. (1990). Robustness and Product Design Families, Design management: a handbook of issues and methods. Moakley. Cambridge, MA. Basil Blackwell Inc.

Wang, H., & Roy, U. (2005). A Graph-Based Method For Mechanical Product Family Modeling And Functional Tolerancing. The 31st Design Automation Conference, ASME IDETC/CIE.

Wang, H., Pramanik, N., Roy, U., Sudarsan, R., Sriram, R.D., Lyons, K.W. (2006). A Scheme for Mapping of Tolerance Specifications to Generalized Deviation Space for Use in Tolerance Synthesis and Analysis. IEEE Transactions on Automation Science and Engineering (T-ASE). 3(1), 81-91.

Wheelwright, S. C., & Clark, K. B. (1992). Revolutionizing Product Development: Quantum Leaps in Speed, Efficiency and Quality. New York, The Free Press.

Whitney, D. (1996). Why mechanical design cannot be like VLSI design. Research in Engineering Design, 8, 125-138.