An inerter nonlinear energy sink for torsional vibration suppression of the rotor system

•An inerter- enhanced NES is proposed for torsional vibration of the rotor system.•The inerter can amplify the rotary inertia of the NES in an adjustable way by levers.•The vibration inhibition ability of INES is verified by test. To reduce size and weight of the inertial mass required in traditional nonlinear energy sink (NES), an inerter nonlinear energy sink (INES) for suppressing the torsional vibration of the rotor system is developed in this paper. The INES is a combination of a NES with piecewise linear stiffness and an inerter whose vibration can be enlarged by levers. The structure of the INES is introduced, the inerter mechanism is analyzed and the dynamic model of the INES-rotor system is built. Vibration attenuation performance of INES on the rotor system is evaluated by the transient torsional vibration and steady-state torsional vibration, both of which are optimized by the genetic algorithm (GA). It is found that the inerter mass of INES can save about 14.2 times its own rotary inertia when suppressing the torsional vibration of the rotor system. By using the inerter, a significant damping effect also appears. In transient torsional vibration suppression, the percentage of accumulated energy dissipation of INES can reach 95.1%. In steady-state torsional vibration suppression, the peak vibration eliminations of INES for the rotor system can achieve 89.1% in simulation and 80.6% in test.