The present paper proposes a novel general approach to automatically calculate the variational parame- ters for planar or cylindrical features for a given set of tolerance specifications, according to ANSI or ISO Stan- dards. Variational parameters correspond to those directions along/around which variation, in terms of small translation and rotation, may propagate for a given feature with toler- ance specifications. A graph representation of these tolerance specifications is adopted and it is used along with screw the- ory and Davies’s laws to automatically calculate the varia- tional parameters, and then the net variational space of each toleranced feature, by capturing nominal geometries directly from a CAD environment (SolidWorks). From screw theory, twist matrices, able to capture the motion properties of any kinematic joint in mechanical assemblies, are here adopted at part level and collected for every feature-to-datum relation- ship. Davies’s laws are then recalled to put those matrices together to calculate the variational parameters. In this way, both single-datum and multi-datum tolerance specifications can be handled. The proposed approach for the automatic calculation of variational parameters could be successfully implemented in a more general expert system for design- ing mechanical assemblies where an added-value interaction could allow user to detect relationships between geometric features. In this way, the leading of activities aimed to toler- ance analysis could be accomplished both during the prelim- inary design stages and throughout the manufacturing and reviewing sessions.

Automatic evaluation of variational parameters for tolerance analysis of rigid parts based on graphs / Pasquale, Franciosa; Salvatore, Gerbino; Lanzotti, Antonio; Patalano, Stanislao. - In: INTERNATIONAL JOURNAL ON INTERACTIVE DESIGN AND MANUFACTURING. - ISSN 1955-2513. - (2013), pp. 1-239. [10.1007/s12008-012-0178-4]

Automatic evaluation of variational parameters for tolerance analysis of rigid parts based on graphs

LANZOTTI, ANTONIO;PATALANO, STANISLAO
2013

Abstract

The present paper proposes a novel general approach to automatically calculate the variational parame- ters for planar or cylindrical features for a given set of tolerance specifications, according to ANSI or ISO Stan- dards. Variational parameters correspond to those directions along/around which variation, in terms of small translation and rotation, may propagate for a given feature with toler- ance specifications. A graph representation of these tolerance specifications is adopted and it is used along with screw the- ory and Davies’s laws to automatically calculate the varia- tional parameters, and then the net variational space of each toleranced feature, by capturing nominal geometries directly from a CAD environment (SolidWorks). From screw theory, twist matrices, able to capture the motion properties of any kinematic joint in mechanical assemblies, are here adopted at part level and collected for every feature-to-datum relation- ship. Davies’s laws are then recalled to put those matrices together to calculate the variational parameters. In this way, both single-datum and multi-datum tolerance specifications can be handled. The proposed approach for the automatic calculation of variational parameters could be successfully implemented in a more general expert system for design- ing mechanical assemblies where an added-value interaction could allow user to detect relationships between geometric features. In this way, the leading of activities aimed to toler- ance analysis could be accomplished both during the prelim- inary design stages and throughout the manufacturing and reviewing sessions.
2013
Automatic evaluation of variational parameters for tolerance analysis of rigid parts based on graphs / Pasquale, Franciosa; Salvatore, Gerbino; Lanzotti, Antonio; Patalano, Stanislao. - In: INTERNATIONAL JOURNAL ON INTERACTIVE DESIGN AND MANUFACTURING. - ISSN 1955-2513. - (2013), pp. 1-239. [10.1007/s12008-012-0178-4]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/564730
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