A Comparison Study of Small Displacement Torsor and Analysis Line Methods for Functional Tolerance Analysis

Abstract:

Tolerance analysis plays an important role in the stage of product design and has great influences on the product assembly quality and manufacturing costs. Two major methods are used for three-dimensional functional tolerance analysis, which are small displacement torsor and analysis line. A positioning mechanism with two parts is presented for tolerance accumulation calculation. Through the comparison of these two methods on computation processes and results, analysis line method can establish the explicit relationship between the functional requirement and the tolerances of the influential part, which allows finding the accumulation results in the worst-case and statistical conditions. However, it requires the determination of transfer relationship case by case. For small displacement torsor model, it permits a set of inequalities to express the tolerance zones, which yields a linear programming problem. It is applicable to different tolerance chains for its general characteristic. However it is adopted only for the worst-case analysis and requires more computation time.

• Periodical: Advanced Materials Research (Volumes 605-607)
• Pages: 358-364
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.605-607.358
• Online since: December 2012
• Authors: Chun Li Li, Jian Xin Yang, Jun Ying Wang, Wen Xin Ma
• Keywords: Analysis Line, Functional Tolerancing, Small Displacement Torsor, Tolerance Analysis

References

[1] B.Anselmetti, Generation of functional tolerancing based on positioning features, Computer-Aided Design, Vol. 38 (2006), pp.902-919.

DOI: 10.1016/j.cad.2006.05.005

[2] ISO Standard, ISO 1101: Geometrical Product Specification (GPS) – Geometrical tolerancing – Tolerance of form, orientation, location and run-out, International Organization for Standardization, (2004).

DOI: 10.3403/30244906

[3] Y.S. Hong and T.-C. Chang, A comprehensive review of tolerancing research, International Journal of Production Research, Vol. 40 (2002), pp.2425-2459.

DOI: 10.1080/00207540210128242

[4] A. Desrochers, W. Ghie and L. Laperriere, Applications of a unified Jacobian-Torsor model for tolerance analysis, ASME Journal of Computing and Information Science in Engineering, Vol. 3 (2003), pp.2-14.

DOI: 10.1115/1.1573235

[5] P. Bourdet, L. Mathieu, C. Lartigue and A. Ballu, The Concept of Small Displacement Torsor in Metrology, Advanced Mathematical Tool in Metrology II (1996), pp.110-122.

[6] A. Mujezinovic, J. K. Davidson and J. J. Shah, A new mathematical model for geometric tolerances as applied to polygonal faces, ASME Journal of Mechanical Design, Vol. 126 (2004), pp.504-518.

DOI: 10.1115/1.1701881

[7] E. Ballot, P. Bourdet and F. Thiebaut, Determination of relative situations of parts for tolerance computation, Proc. 7th CIRP International Seminar on Computer Aided Tolerancing, ENS de Cachan, France, (2003), pp.63-72.

DOI: 10.1007/978-94-017-1691-8_7

[8] B. Anselmetti, Cotation fonctionnelle tridimensionnelle et statistique, Hermes Lavoisier Edition, (2008).