Manufacturing signature in jacobian and torsor models for tolerance analysis of rigid parts

Abstract

Geometric deviations characterize manufactured workpieces and have great influences on the quality and function of mechanical products. Therefore, geometric variations management has to be performed to ensure the product function despite the presence of these deviations. Dimensional and Geometric Product Specification and Verification (GPS) are standards for the description of the workpiece. The Skin Model is an abstract concept of the physical interface between a workpiece and its environment. In contrast to this understanding, established models for computer-aided modelling and engineering simulations make severe assumptions about the workpiece surface. Therefore, this paper deals with operationalizing the Skin Model concept in discrete geometry for the use in geometric variations management. The Skin Model Shape has been connected with manufacturing processes, in order to bring closer the Computer Aided Tolerancing (CAT) simulation tools to reality. The pattern left by a turning process has been considered the discrete geometry framework of the skin model shape of the assembly components in a tolerance analysis approach. The obtained results are significantly different from those due to the traditional approaches. The aim of this paper is to connect the Skin Model to the manufacturing processes.Correlation among manufactured surface points constitutes the framework of the Skin Model.The manufacturing Skin Model was integrated into the jacobian and the torsor models.The new Jacobian and torsor models were applied to a three parts assembly.The obtained results were compared with those due to the jacobian and torsor models.