Development of a Computer-Aided integrated method for the tolerance-cost multi-disciplinary optimization of an automotive engine

Geometric and dimensional deviations are the main contributors on quality and cost of products. Specifically, the selection of tolerance types and the appropriate allowable range plays a central role for an effective development process. Nevertheless, the trade-off between expected performances and target costs requires skills and interaction of many areas of engineering design, especially in the early design phases. Despite many tolerance-cost optimization practices are proposed by the research community several limitations still hamper the industrial application: among them, data and parameters sharing, flexibility to application complexity, and integration of simulation tools are the main ones. Focusing on a systematic framework, an integrated modelling and simulation environment is required to take full advantage of the concurrent use of engineering software. The present paper contributes to this aim by suggesting a Computer-Aided framework that integrates Geometric Dimensioning and Tolerancing simulations and manufacturing cost estimations in a multi-disciplinary optimization environment. Advanced tools are the cornerstones of the suggested framework, enabling easy identification of the main operational steps and providing the automation of the optimization. To be validated and demonstrate the effective applicability, the framework has been applied for the tolerance-cost optimization of an archetypal case study of an automotive engine assembly. The simulation models have been integrated within the optimization, providing several configurations of tolerances from which identify the optimal one. The analysis of optimization results allows to assess the efficiency of the method, highlighting further improvements to extend its robustness, flexibility, and application range.