Dynamic Characteristics Analysis of a Rod Fastening Rotor System Considering Contact Roughness

A rod fastening rotor is the core component of gas turbines, which affects the working stability and service life of the whole machine. The characterization of the contact mechanism of a joint’s interface is a key problem in dynamic prediction. The aim of this paper is to gain insight into the influence of the joint’s interface on the dynamic characteristics of the rod fastening rotor system. According to the equivalent bending stiffness of the joint’s interface, the natural frequency of the system is obtained by the analytical method, where the normal contact stiffness of the joint’s interface related to the frequency index is established on the theory of fractal contact analysis. After that, the effects of key parameters on the contact stiffness are discussed in detail. Finally, the variations in the vibration frequency are further revealed as well.