Steady-state analysis of a rotor mounted on nonlinear bearings by the transfer matrix method

The steady-state responses of subharmonic, superharmonic and synchronous vibrations of a flexible rotor supported by bearings of power nonlinearity (i.e. the bearing force satisfies a power law of the deflection) are studied. The transfer matrix method is applied to formulate the transfer matrices of nonlinear rotor-bearing systems with MDOF (multi-degree of freedom) and in conjunction with the harmonic balance method to obtain the steady-state responses. Two examples of rotor-bearing systems with cubic nonlinearity spring characteristics are given to investigate the effects of nonlinearity on frequency response and the whirling orbits.