Tolerance Simulation of Compliant Sheet Metal Assemblies Using Automatic Node-Based Contact Detection

Abstract

Tolerance simulation is a crucial tool for predicting the outcome in critical dimensions, and is used during early phases of product development in automotive industry. In order to increase the accuracy and the agreement with reality of the predictions even further, variation simulation software offer in some cases the possibility to perform compliant analysis, i.e. the parts are not restricted to be rigid. In compliant analysis contact modeling is an important feature. In this paper a simplified method for automatic contact detection, well suited for tolerance simulations, is suggested. Traditionally, those kinds of non-rigid simulations are very time consuming, but by using this kind of simplified contact modeling in the Monte Carlo simulations, the simulation times can be kept down. The method is tested on an industrial case study. The analyses are done with and without contact modeling and those results are compared to real inspection data. The contact modeling turns out to be an important feature; the correlation between the results with contact modeling and inspection data is much stronger than the correlation for simulations without contact modeling. When using the new contact modeling algorithm the correspondence between simulated data and inspection data is very satisfying and the algorithm seems to be faster than traditional finite element software.