A multi-stable nonlinear energy sink for torsional vibration of the rotor system

A multi-stable nonlinear energy sink (MNES) is presented and coupled to a rotor system to suppress torsional vibration. The nonlinear stiffness of the MNES is produced by sinusoidal beam which can generate negative stiffness. The torsional vibration responses of the rotor-MNES system under transient and steady-state excitation are evaluated numerically while the damping results are optimized by genetic algorithm (GA). And also, the snap-through motion (STM) of the MNES is observed, the influence of parameters on the vibration suppression of the MNES is analyzed and the vibration suppression effect is compared with a linear dynamic vibration absorber (LDVA). Finally, the experimental verification of the steady-state torsional vibration suppression of the MNES is carried out. The results show that the accumulated energy dissipation percentage of the MNES can reach 91.5% in transient torsional vibration suppression, and the vibration suppression of the MNES is 79.4% in simulation and 77.6% in test in steady-state torsional vibration suppression. And also, when the MNES and a LDVA have the same inertial mass, the vibration suppression performance of MNES is better.