Stiffness Loss of Curvic Coupling Under Bending Vibration and Its Effect on Dynamic Characteristics of Rotor Systems

Aiming at the complex mechanical characteristics of the curvic coupling in the aero-engine rotor under operation condition, the contact stiffness model of the curvic coupling under the bending vibration is proposed to study the law of stiffness loss of the curvic coupling and the dynamic characteristics of the rotor with the curvic coupling under the bending vibration. Based on the Hertz contact theory and the elastic-plastic contact theory, an analytical model for the contact stiffness of the three-dimensional curvic coupling is established considering the complex geometric characteristics of the curvic coupling. And the law of stiffness loss of the curvic coupling under the bending vibration is studied. Then, a finite element model of the rotor system is proposed and the dynamic characteristics of the rotor system is analyzed. The results are tested and verified. The results show that the stiffness loss of the curvic coupling under the bending vibration is increased and the critical speed of the rotor is decreased caused by the increased stiffness loss. The contact stiffness model and research conclusions proposed in this paper provide an important theoretical basis for the design and dynamic characteristics analysis of modern aero-engine rotor systems.