Manufacturing signature in variational and vector-loop models for tolerance analysis of rigid parts

Abstract

To control and to manage the geometric deviations along the product life cycle, the first step is to consider, during the design stage, the tolerance specification, the tolerance allocation and the tolerance analysis. Many approaches of the literature for tolerance analysis of rigid assemblies exist, and different commercial computer-aided tolerancing (CAT) software packages were developed with those models. However, there is a growing interest in considering working conditions and operating windows in CAT. As a response to these needs, skin model concept was proposed. The aim of this paper is to connect a point cloud-based discrete geometry framework (i.e. a skin model representation) to the manufacturing processes, in order to bring the CAT simulation tools closer to reality. In this work, the effect of a manufacturing process on solving a stack-up function is investigated throughout circular profiles obtained by a turning process. A case study has been defined and solved using two literature models, the variational model and the vector-loop one, by considering the manufacturing signature. The results have been compared to those obtained by the same models without considering the manufacturing signature. Monte Carlo simulations have been carried out by solving the stack-up functions into Matlab® software, and statistical analyses have been carried out by Minitab® software.