Computer Aided Tolerancing - Solver and Post Processor Analysis

Abstract

The world of the designer is three dimensional, and the language of tolerancing is a set of ISO specifications. We have built a methodology in order to compute geometric specifications on parts and clearances in joints through a mathematical model based on the small displacement torsors. A tolerancing object becomes a 6D object thanks to the developed solver. One objective is to represent 6D polytopes in the 3D world of the designer in order to inform him of the results for his tolerancing choices: assemblability performance, best and worst precision zones, and functional requirements. Therefore, it is necessary to indicate, the results to the designer graphically. This representation will be done in a CAD application by means of zones (3D volumes), which will be associated with functional features of the mechanism. An assembly example is presented to illustrate this method.

Tolerancing: Managing uncertainty from conceptual design to final product

“…Huang and Ceglarek [147] proposed discrete-cosinetransformation (DCT) based on decomposition method for form defects modeling. Samper et al [251] developed the Discrete Modal Decomposition (DMD) considering modal shapes of a discretized feature. Usually, the technical interpretation of these modal representations is not easily achieved.…”