Statistical tolerance analysis of a hyperstatic mechanism, using system reliability methods
TypeArticles dans des revues avec comité de lecture
The quality level of a mechanism can be evaluated a posteriori after several months by following the number of warranty returns. However, it is more interesting to evaluate a predicted quality level in the design stage: this is one of the aims of statistical tolerance analysis. A possible method consists of computing the defect probability (PD) expressed in ppm. It represents the probability that a functional requirement will not be satisfied in mass production. For assembly reasons, many hyperstatic mechanisms require gaps, which their functional requirements depend on. The defect probability assessment of such mechanisms is not straightforward, and requires advanced numerical methods. This problem particularly interests the VALEO W.S. company, which experiences problems with an assembly containing gaps. This paper proposes an innovative methodology to formulate and compute the defect probability of hyperstatic mechanisms with gaps in two steps. First, a complex feasibility problem is converted into a simpler problem. Then the defect probability is efficiently computed thanks to system reliability methods and the m-dimensional multivariate normal distribution Um. Finally, a sensitivity analysis is provided to improve the original design. The whole approach is illustrated with an industrial case study, but can be adapted to other similar problems.
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BEAUCAIRE, Paul; GAYTON, Nicolas; DUC, Emmanuel; DANTAN, Jean-Yves (Elsevier, 2013)One of the aim of statistical tolerance analysis is to evaluate a predicted quality level in the design stage. A method consists in computing the defect probability D P expressed in parts per million (ppm). It represents ...
Statistical tolerance analysis of over-constrained mechanisms with gaps using system reliability methods BEAUCAIRE, Paul; GAYTON, Nicolas; DUC, Emmanuel; DANTAN, Jean-Yves (Elsevier, 2013)One of the aims of statistical tolerance analysis is to evaluate a predicted quality level at the design stage. One method consists of computing the defect probability PD expressed in parts per million (ppm). It represents ...
A statistical tolerance analysis approach for over-constrained mechanism based on optimization and Monte Carlo simulation QURESHI, Ahmed Jawad; DANTAN, Jean-Yves; SABRI, Vahid; BEAUCAIRE, Paul; GAYTON, Nicolas (Elsevier, 2012)Tolerancing decisions can profoundly impact the quality and cost of the mechanism. To evaluate the impact of tolerance on mechanism quality, designers need to simulate the influences of tolerances with respect to the ...
DANTAN, Jean-Yves; GAYTON, N.; QURESHI, Ahmed Jawad; LEMAIRE, Maurice; ETIENNE, Alain (Elsevier, 2013)Uncertainty is ubiquitous in tolerance analysis problem. This paper deals with tolerance analysis formulation, more particularly, with the uncertainty which is necessary to take into account into the foundation of this ...
DUMAS, Antoine; ECHARD, Benjamin; GAYTON, Nicolas; ROCHAT, Olivier; DANTAN, Jean-Yves; VAN DER VEEN, Sjoerd (Elsevier, 2013)Tolerance verification permits to check the product conformity and to verify assumptions made by the designer. For conformity assessment, the uncertainty associated with the values of the measurands must be known. In fact, ...