Research on Rub-Impact Vibration of a Bolted Joint Rotor System with Non-Uniform Preload

This paper aims to establish a new dynamic model of a bolted rotor system that takes into account rubbing faults and non-uniform preload, and comprehensively studies and analyzes the effects of rubbing faults and non-uniform preload on the dynamic response of the rotor system. A dynamic model of a bolted joint rotor system is established based on the lumped mass modeling approach. The dynamic response of the rotor system is computed using the Newmark-β numerical integration method. Parametric studies investigate the effects of rubbing faults and non-uniform preload on the system’s dynamical behavior. Results demonstrate that the coupling between rubbing faults and piecewise linear stiffness characteristics exacerbates critical speed reduction while increasing vibration amplitude. Furthermore, experimental validations conducted on a bolted joint rotor system equipped with a rubbing device partially verify the numerically predicted results regarding the effects of non-uniform preload and rubbing faults on rotor dynamic characteristics. This paper draws some conclusions on the dynamics of bolted rotors based on rubbing fault and non-uniform preload by comparing numerical and experimental results, which are of reference value for the motion control and fault diagnosis of bolted rotor systems.