Vibration mitigation of a nonlinear rotor system with linear and nonlinear vibration absorbers

Steady state dynamics of a horizontally supported Jeffcott rotor system under nonlinear restoring forces has been studied in this work. Vibration reduction of the rotor system using linear tuned mass dampers (TMD), nonlinear energy sinks (NES), and combined energy sinks (TMD-NES) was studied. In addition, the analysis on the effects of different parameters on the dynamics of the rotor system has been conducted. In this study, semi-analytical modified complex averaging technique (MCXA), numerical arc-length continuation method, and ODE integration method have been used to solve the governing equations. The obtained results showed, all three types of absorbers including TMD, NES, and combined TMD-NES sufficiently good performance in vibration reduction of primary rotor system. In a closer view, it shows that TMD-NES, TMD, and NES have respectively better performance in vibration reduction. On the other hand, combined TMD-NES, NES, and TMD give respectively broader frequency range of stability. Finally, it's concluded that in spite of good efficiency in vibration reduction for the design condition, all types of absorbers should be modified to be more robust against changes in parameters of primary system.