Robust lightweight design and digital twins considering manufacturing quality variation and sustainability requirements

In this paper, robustness optimization of a fatigue-critical welded structure with measured misalignments and a generic robust design procedure are presented. The motivation for considering uncertainties, robustness and multi-criteria decision making in engineering design comes from the increasing sustainability requirements. Lightweight design of vehicles can reduce CO2 emissions and increase energy and material efficiency, but often the fatigue of welds limits the weight reduction. The manufacturing quality affects the fatigue strength of welds, and by quantifying the manufacturing quality and using robust design methodology the increasing sustainability requirements can be met, while also considering the technical and economical constraints. The surrogate model representing the relationship between the actual, measured geometry and the fatigue life can be used as the digital twin during operation.