Model-Based Definition for Non-Rigid Variation Simulation I: Automating Tolerance Analysis with the Quality Information Framework (QIF)

Abstract

The Quality Information Framework (QIF) standard aims to cover the whole product quality ecosystem using a Model-Based Definition approach. Compared to the STEP AP242 and JT standard, QIF concentrates on semantically intertwining information from product design and inspection within one information carrier. Due to its strong focus on geometrical product quality, QIF is predestined to be used as the basis for activities that aim to assure product quality in the presence of geometrical variations. Still, its potential for variation simulation, virtually predicting the effects of geometrical part and assembly variations on the final product quality, remains largely unexploited. Methods for bringing information from QIF to variation simulation and translating it into deviations are currently lacking. This article presents a novel QIF-based method that fosters the automation of deviation modeling in non-rigid variation simulation of sheet metal assemblies. Building upon an inverse mapping method for registering QIF features within shell meshes leads to a hybrid model that combines the strengths of a parametric and discrete geometry representation. By exploiting this duality, size, location, orientation, and form tolerances are translated into mesh deviations using a joint Small Displacement Torsor and Skin Model Shapes approach. An exemplary application of the proposed method to a spot-welded sheet metal assembly illustrates QIF’s potential for bridging feature-based GD&T specification and mesh-based variation simulation.