Based on mechanical properties of rotor nonlinear vibration and the assumption of large deformation

the rotor nonlinear vibration model in the form of Duffing equation was constructed from typical engineering problem.According to analytical solutions of Duffing equation

system's equivalent frequency and frequency response equation were derived.The system's vibration influences of stiffness components

damping components and nonlinear components were studied.The single-disc rotor nonlinear vibration experimental results verified the rationality and efficiency of nonlinear vibration model's construction and Duffing equation's analytical solution and frequency response equation.The mechanisms of resonance

amplitude jump and hysteresis are revealed.It provides a new research method for rotor vibration characteristics analysis.