Abstract
This article introduces research on nonlinear rotordynamics in Japan. In most cases, the nonlinearity treated there was weak and it was approximated by a power series of low order. Firstly, the research on various nonlinear resonances due to the weak nonlinearity is introduced. Next, those on more complicated nonlinear phenomena, such as entrainment, internal resonances, chaotic vibrations, nonstationary vibrations, and more complicated systems, such as cracked rotors and continuous rotors, are explained. Then, research on phenomena due to strong nonlinearity is introduced. Various vibration suppression methods where the nonlinearity plays an important role are also explained. Finally, studies on the models representing helicopters and wind turbines are explained.
