Robust optimization of nonlinear energy sinks used for mitigation of friction-induced limit cycle oscillations

This paper aims at proposing robust methods to optimize nonlinear energy sinks (NES) used for the mitigation of friction-induced vibrations due mode coupling instabilities. The study is based on a mechanical system composed two NES coupled well-known two-degrees-of-freedom Hultèn’s model. In such an unstable with NES, it usual observe discontinuity in steady-state amplitude profile which separates parameter space into parts corresponding respectively mitigated and unmitigated regimes. predicted by methodology previously developed authors Multi-Element generalized Polynomial Chaos. method allows determine Propensity undergo Harmless Steady-State Regime (PHSSR). objective present work therefore maximize value PHSSR obtain optimal design NES. To this end, several stochastic optimization problems are presented that take account dispersion uncertain parameters using approaches; first one, considered as deterministic, second one they also supposed but known probability law. • A friction NESs studied. Robust performed ME-gPC method. consists Regime. can be