Enhancing product robustness in reliability-based design optimization

Different types of uncertainties need to be addressed in a product design optimization process. In this paper, the uncertainties in both product design variables and environmental noise variables are considered. The reliability-based design optimization (RBDO) is integrated with robust product design (RPD) to concurrently reduce the production cost and the long-term operation cost, including quality loss, in the process of product design. This problem leads to a multi-objective optimization with probabilistic constraints. In addition, the model uncertainties associated with a surrogate model that is derived from numerical computation methods, such as finite element analysis, is addressed. A hierarchical experimental design approach, augmented by a sequential sampling strategy, is proposed to construct the response surface of product performance function for finding optimal design solutions. The proposed method is demonstrated through an engineering example. •A unifying framework for integrating RBDO and RPD is proposed.•Implicit product performance function is considered.•The design problem is solved by sequential optimization and reliability assessment.•A sequential sampling technique is developed for improving design optimization.•The comparison with traditional RBDO is provided.