Nonlinear Dynamic Characteristics Analysis of Diaphragm Coupling Rotor System with Crack Fault

The diaphragm coupling may have crack failure under long-term high-speed working conditions. In this paper, the dynamic model and experimental model of the diaphragm coupling rotor system with crack fault are established, and the influence of the diaphragm crack fault on the dynamic characteristics of the rotating subsystem is studied. The nonlinear finite element model of the diaphragm coupling with crack fault is established by ANSYS to solve the stiffness matrix. The results show that the crack fault will reduce the amplitude of the angular stiffness and the radial stiffness of the diaphragm, and introduce a frequency doubling component to the time-varying angular stiffness and time-varying radial stiffness of the diaphragm coupling. The dynamic model of the rotor system is established, and the influence of crack failure on its dynamic characteristics is analyzed. The results show that the introduction of crack failure will make the axis locus of the system more complicated, and there are obvious frequency-doubling components in the frequency domain. Finally, the accuracy of the dynamic model and the effectiveness of the recognition signal are verified by constant velocity experiments.