Design of a NES device via efficient stochastic linearisation

Abstract

Non-linear energy sinks (NES) are often used to mitigate the dynamic response of structures, but its large-scale use and design have been limited by their inherent non-linearities. Assuming that loads are random in nature, the stochastic analysis of non-linear systems may be done through computational intensive techniques as Monte Carlo simulations (MCS). Alternatively, the Stochastic Linearisation (SL) technique has proven to be an effective tool. Since, in general, controlled systems are non-classically damped and most of SL algorithms operate recursively, the computational burden required is still large for those problem that make intensive use of SL technique, like passive control optimal design procedures. In this study, a procedure to speed up the Stochastic Linearisation technique by avoiding numerical evaluations of response statistics is proposed and an application have been carried out on a well-known case study related to the vibrations mitigation of an aircraft wing. The ability of the proposed procedure to effectively reduce the computational effort and to reliably design the optimal passive control device is showed.