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The tolerance analysis aims to check if the tolerances specified on mechanism components allow to respect the assembly and functional requirements. Several papers illustrate that the form defects have an impact on the mechanism behavior, but most tolerance analysis techniques neglected them. To perform the tolerance analysis, three issues must be addressed: the geometrical deviations modelling, the geometrical behavior modelling and the technique of tolerance analysis. Therefore, this paper presents one contribution for each issue to perform tolerance analysis of over-constrained mechanism with form defect: • Modal representation of the form defect • Behavior modelling technique of the contact with form defect • Tolerance analysis technique with the integration of the different contact types. [ABSTRACT FROM AUTHOR]

The tolerance analysis aims to check if the tolerances specified on mechanism components allow to respect the assembly and functional requirements. Several papers illustrate that the form defects have an impact on the mechanism behavior, but most tolerance analysis techniques neglected them. To perform the tolerance analysis, three issues must be addressed: the geometrical deviations modelling, the geometrical behavior modelling and the technique of tolerance analysis. Therefore, this paper presents one contribution for each issue to perform tolerance analysis of over-constrained mechanism with form defect: • Modal representation of the form defect • Behavior modelling technique of the contact with form defect • Tolerance analysis technique with the integration of the different contact types. [ABSTRACT FROM AUTHOR]

Abstract The general scope of tolerancing analysis with polytopes, more precisely by polytopes in double description: with half-spaces (half-spaces= constrains) and with vertex (vertex= extremal displacement), consists in modeling the displacement restrictions of a surface in a tolerance zone or between two surfaces of two distinct parts potentially in contact. Initially these works were developed to simulate the variations of ideal surfaces with no form variation. This article presents an original methodology to overcome this limitation. The evolution of the polytope topology and the associated quantification will be presented. This approach will be applied on double descriptions. [ABSTRACT FROM AUTHOR]

In tolerancing analysis area, the most various existing approaches do not take form defects of parts into consideration. As high precisions assemblies cannot be analyzed with the assumption that form defects are negligible, the paper focuses in particular on the study of the form defects impacts on the assembly simulation and that by comparing two optimization algorithms (iHLRF and Quapro). The study is limited firstly to the cylinders. For the optimization, two main types of surfaces modelling are considered: difference surface-based method and real model. The compared models allow assessing the non-interferences between cylinders with form defects, potentially in contact. This is in the main issue to validate a tolerance analysis approach. [ABSTRACT FROM AUTHOR]