Nonlinear dynamic simulation and parametric analysis of a rotor-AMB-TDB system experiencing strong base shock excitations

The application of active magnetic bearings (AMBs) enables turbomachinery to increase power density, controllability and resilience external disturbances. However, due the limited load capacity AMBs, base shock excitations may result in contact between rotor touchdown (TDBs), which can seriously damage machine. This paper presents a dynamic analysis rotor-AMB-TDB system experiencing strong shocks while AMBs are operating. contacts TDBs, rolling-ball within TDBs modeled based on Hertzian theory. A PD controller is designed, considering saturation. equations were solved numerically, results showed three different motion modes after shocks. FFT spectra, STFT Poincaré maps bifurcation diagrams used for analysis. Unsuitable parameters, including unbalance eccentricity, radial clearance, equivalent stiffness damping ratio, lead complex behaviors periodic, KT-periodic, quasi-periodic responses as well jump phenomena. study reveals mechanism nonlinear responses, provides method predictions, helps with designs re-levitation.