A Comparative Analysis of Different Robust Design Approaches in Sheet Stamping Operations

Abstract

A crucial issue in sheet stamping optimization problems is related to the process robustness improvement: critical scattering in the investigated performances arises due to some noise variables influence, often evolving up design failure itself. In fact, strong variations in the final stamped part or fluctuations of strain distribution may lead to an uncontrolled process design. Such variability cannot be controlled but anyway it is possible to develop proper design tools able to identify robust process calibrations above which the noises variations effects are admissible. In this paper, a multi‐objective optimization problem was analyzed, with the aim to minimize both excessive thinning and springback occurrences in a sheet stamping process of an aluminum alloy. In fact, major stamping operations are characterized by conflicting goals to be accomplished, introducing a further difficulty in the process variability control. Two kinds of robust design approaches were compared, a hybrid deterministic‐stochastic framework and a dual response based approach, with the aim to analyze how each kind of approach may address the final design choices. Actually, the variability investigation may be considered as final robustness evaluation, otherwise the process may be calibrated under the stochastic effects of the noise variables.