Session: 02-09-01: Session #1: Variation Simulation and Design for Assembly Description

Paper Number: 91890

91890 - A Hierarchical Approach for the Verification and Validation of Tolerance Analysis Models 

Established tolerance analysis methods are capable of predicting the effects of geometrical part deviations on the quality of products and hence virtually assuring their functionality at an early design stage. However, experience-based assumptions and simplifications are often made in tolerance simulations, mostly for reducing the computational effort, in terms of system behavior and geometrical models which can however lead to decisive uncertainties in the simulation models and results. In order to omit a significant effect of these uncertainties on the overall model and thus on the obtained results, both a virtual assessment of the model and its submodels and an experimental validation test comparing simulatively and experimentally determined data are necessary. The current state of the art however lacks suitable quantifiable and generally applicable methods and metrics to reliably evaluate the results of tolerance analyses compared to experimentally gathered data. In addition, an approach is needed to investigate and evaluate the effects of uncertainties in submodels within the analysis model on the overall model. The aim of this contribution is therefore to derive general statements about the suitability and significance of certain quantifiable methods and metrics of verification and validation for evaluating simulation models and their feasibility in the context of tolerance analysis. Therefore, first, general methods and metrics for the evaluation of simulation results are presented according to the current state of the art in the context of verification and validation. A consequent methodical assessment and a comparative analysis evaluates their feasibility as well as their limits and constraints for an application to tolerance analysis models and the obtained results. Subsequently, the most promising ones are customized and applied for the verification and validation of results of statistical tolerance analysis contrasting simulation and real measurement data. The statistical tolerance analysis of a planar, 3-D-printed non-assembly mechanism in motion taking into account process-specific variations is chosen as an exemplary case study for application. For gathering real measurement data, an experimental setup including optical measurement serves as the basis for a for a quantifiable assessment of the respective case study. Finally, the presented approach including the methods and metrics are discussed on their prospects and limits based on the obtained results from the case study concerning their suitability and reliability for assuring the validity of the tolerance analysis results in general. The results of applying the approach within the case study confirm the theoretical findings and highlight the utility and benefits of the proposed approach. 

Presenting Author: Paul Schaechtl Friedrich-Alexander-Universität Erlangen-Nürnberg

Presenting Author Biography: Paul Schaechtl is a research associate and PhD student in the research group ‘dimensional management’ at the Institute of Engineering Design of the Friedrich-Alexander-Universität Erlangen-Nürnberg. In his current research, he focuses on virtual product development and computer-aided tolerancing in the field of additive manufacturing. His area of expertise is the analysis and improvement of geometrical accuracy in additive manufacturing and the integration and consideration of process information in the virtual product development.

Authors:

Paul Schaechtl Friedrich-Alexander-Universität Erlangen-Nürnberg
Benjamin Schleich Friedrich-Alexander-Universität Erlangen-Nürnberg
Sandro Wartzack Friedrich-Alexander-Universität Erlangen-Nürnberg