Research on Crack Detection of Nonlinear Rotor Based on Energy Tracks

In rotating machinery, because of high-speed working characteristics and terrible working conditions with variable cycles and variable loads, it is easy for rotors to cause a crack initiation and propagation, which may cause serious harm or even the life-threatening. The super harmonic component is an important role of the crack detection. But it is difficult to reflect the super harmonic component in the high-speed region after super harmonic resonances. In this paper, the dynamic equation of a nonlinear rotor system with a crack is considered, the potential energy expression of the cracked rotor is derived, and the concept of energy tracks is proposed. In the distortion of energy tracks, the effects of different crack parameters and nonlinear parameters on the vibration characteristics of the rotor system are compared. The results show that the energy trajectory distortion can diagnose the crack fault. It provides a new research method for vibration response analyses and fault diagnoses of cracked rotor system.