Advantages of vibro-impact nonlinear energy sinks for vibration suppression of continuous systems: Coexistence of inter-modal energy scattering and targeted energy transfer

Abstract

Nonlinear energy sink (NES) is a lightweight nonlinear device that is attached to a primary system for passive energy localization into itself. In this paper, the energy transfer mechanism of the vibro-impact nonlinear energy sink (VI-NES) in continuous systems, and its consequences in vibration suppression is addressed. We uncovered the significance of a new distinctive energy transfer phenomenon termed inter-modal energy scattering (IMES), which was largely overlooked by most of the investigations concerning VI-NES. Considering a coupled system consists of a cantilever beam and an attached VI-NES, the non-smooth dynamics of the system is first formulated in a measure differential complementarity problem and treated using an energy-conserving integration method. Then the energy transfer mechanisms including the common targeted energy transfer (TET), the IMES, and their coexistence effect, are comprehensively investigated. Finally, the vibration damping performance of the VI-NES for the beam under harmonic force, broadband white noise, and transient shock excitations are also discussed and compared to other types of absorbers. It is demonstrated that the IMES is a distinctive phenomenon that can be realized only in the types of NESs with non-smooth vibro-impacts, to allow a broadband transfer of vibration energy among the eigenmodes of the host beam, resulting in hence a much more effective vibration reduction than the tuned mass damper (TMD) or other NESs.