A Theoretical and Experimental Investigation of Double Resonances of a Rotor-Shafting Torsional Vibration System of a Turbogenerator Set
Qiu Jiajun  Yang Zhian  Cai Ganhua
(Dept. of Mechanics & Engineering Measurements, Tianjin University)

Abstract: In this paper, a rotor-shafting torsional vibration system of a turbogenerator
set with quadratic nonlinearities to a simple harmonic excitation is investigated.By the use of the method of averaging, the first approximate solution and corresponding steady-state solution are obtained while W₁ about equal to 2W₁,and A about equal to w₁.The paper points out that the response curves exist jump phenomenon, and the topological structures of the response curve are decided by the physical parameters of the system. As internal resonance is insufficient detuning, response curves demonstrate soft characteristics; as internal response is complete detuning,response curves are symmetric and are of M shapes; as internalr esponse is excessive detuning, response curves demonstrate hard characteristics.The results of theoretical analysis are shown to be in good agreement with experimental results.
Keywords: rotor-shafting torsional vibration,double responses, internal resonance, themethod of averaging, insufficient detuning, excessive detuning.