Traveling-wave vibrations of disc-drum rotors with PSC under mistuning-coupled conditions

Abstract

This study emphasizes the considerations of both strain-dependent characteristics for partial coatings in the rotatory state and multiple mistuning-coupled conditions, both of which are difficult to find in reported studies. Due to the initial manufacturing error and the coupling loosening, the mistuning coupling does exist. It can induce local vibration exceeding standards, so the vibration-suppression demand is strong. The damping effect of strain-dependent coatings is significant, and compared with coatings on entire surfaces, partial coatings are easier to meet actual needs. Therefore, this study seems to have a certain significance and innovation. Firstly, the existing spring technology is improved to simulate connection-angle mistuning, connection-stiffness mistuning, and arc-length mistuning. Considering the centrifugal and gyroscopic effect of the disc and drum, the dynamic model of disc-drum rotors with partial strain-dependent coatings (PSC) under multiple mistuning-coupled conditions is created. Secondly, the multi-zone decomposing method is developed for presenting a united method of introducing the strain-dependent characteristics of partial coatings in the rotatory state, and the matching method of solving the nonlinear model is also provided. The validity of the model is verified. Finally, traveling-wave vibration analyses show that the Coriolis effect seriously affects the number of frequency-curve veering and the evolution of the vibration modes in veering regions. Moreover, the mistuning coupling induces the increase of frequency-curve veering, and also significantly influences vibration modes, towards of frequency curves, and response-distribution situations.