A. Gérard - Academia.edu (original) (raw)

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Papers by A. Gérard

Research paper thumbnail of Evaluation de l'énergie mise en jeu et du comportement des outils de coupe dans l'usinage

Research paper thumbnail of A computer aided tolerancing model: proportioned assembly clearance volume

Computer-Aided Design, 1999

The object of this article is to present a tolerancing model, the "Proportioned Assembly Clearanc... more The object of this article is to present a tolerancing model, the "Proportioned Assembly Clearance Volume: PACV". The finality of the PACV is to create a three-dimensional (3D) tolerancing analysis tool that takes into account only standardized specifications. The PACV is based on the Small Displacements Torsor (SDT) concept. SDT is used to express the relative position between two ideal surfaces. The rotations between two geometric features are linearized, i.e. displacements are transformed into small displacements. An ideal surface is a surface, which can be characterized by a finite number of geometric features: point, centerline, part face, etc. A nominal surface is an ideal surface by definition. By modeling fabricated surfaces in ideal surfaces, it is possible to compute the limits of small displacements of a fabricated surface inside a tolerance zone. The values of these limits define a PACV. With a similar method, the limits of small displacements between two surfaces of two distinct parts, e.g. clearance in a joint, can be determined: they define a PACV. Using a graph, we illustrate how PACV (edges) could be associated in series or in parallel between two any surfaces (vertices) in an assembly, in order to create 3D dimension-chains. The governing rule of PACV in series is introduced. In addition, one example of computation of 3D dimension-chain (result of an association of PACV in series) is presented. ᭧

Research paper thumbnail of Evaluation de l'énergie mise en jeu et du comportement des outils de coupe dans l'usinage

Research paper thumbnail of A computer aided tolerancing model: proportioned assembly clearance volume

Computer-Aided Design, 1999

The object of this article is to present a tolerancing model, the "Proportioned Assembly Clearanc... more The object of this article is to present a tolerancing model, the "Proportioned Assembly Clearance Volume: PACV". The finality of the PACV is to create a three-dimensional (3D) tolerancing analysis tool that takes into account only standardized specifications. The PACV is based on the Small Displacements Torsor (SDT) concept. SDT is used to express the relative position between two ideal surfaces. The rotations between two geometric features are linearized, i.e. displacements are transformed into small displacements. An ideal surface is a surface, which can be characterized by a finite number of geometric features: point, centerline, part face, etc. A nominal surface is an ideal surface by definition. By modeling fabricated surfaces in ideal surfaces, it is possible to compute the limits of small displacements of a fabricated surface inside a tolerance zone. The values of these limits define a PACV. With a similar method, the limits of small displacements between two surfaces of two distinct parts, e.g. clearance in a joint, can be determined: they define a PACV. Using a graph, we illustrate how PACV (edges) could be associated in series or in parallel between two any surfaces (vertices) in an assembly, in order to create 3D dimension-chains. The governing rule of PACV in series is introduced. In addition, one example of computation of 3D dimension-chain (result of an association of PACV in series) is presented. ᭧

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