Nonlinear inverse unbalance reconstruction in rotor dynamics

This article is devoted to the identification and reconstruction of unbalance distributions in an aircraft engine rotor with a nonlinear damping element. We have developed a rotor model that takes into account the nonlinear behavior of a squeeze film damper between the engine's shaft and casing for large oscillation amplitudes. Based on the Tikhonov regularization for nonlinear ill-posed problems, we provided a three-step algorithm that enables us to identify and reconstruct single and distributed unbalances from data measured at the casing of the engine. In view of practical capability, the algorithms were accelerated to meet the requirement of tolerable computation time for larger models, too.