Robust structural optimization in presence of manufacturing uncertainties through a boundary-perturbation method

Most manufacturing processes are inevitably characterized by process tolerances that ultimately affect the way a component behaves and complies with the design requirements. These uncertainties determine the real performance of a structure, with their impact growing with increasing deviations from the nominal values. This work introduces a simple approach, applicable to both static and dynamic cases, to conduct robust structural topology optimization in presence of manufacturing uncertainties. This approach, based on the level set method, makes use of a computationally efficient boundary-perturbation technique to describe over- and under-etching errors. Compared to the existing methods, it does not require a frequent re-initialization of the level set function, nor does it require a mapping between the etched structures and the nominal one. Moreover, compared to the standard case with uniform uncertainty, the technique presented in this work allows dealing with arbitrary spatially varying errors without increasing the computational cost.