Chaotic Vibration and Internal Resonance Phenomena in Rotor Systems: Part II — Experimental Analysis
In the practical rotating machinery, the gyroscopic moment is often small. In addition, some mechanical elements of a rotor system make various types of nonlinearity. In such rotor systems, the natural frequency of a forward whirling mode pf and that of a backward whirling mode pb almost satisfy the relation of internal resonance pf : pb = 1 : (−1). However there are few studies on the nonlinear phenomena of the rotor systems due to the influence of internal resonance, especially the experimental investigation have not been reported. In this study, we investigate experimentally the dynamical characteristics of nonlinear phenomena due to the internal resonance at the major critical speed and at two times of the major critical speed. The following are clarified experimentally: (a) the amplitude modulated vibration due to Hopf bifurcation from the steady state vibration occur and then the chaotic vibration occur at the major critical speed, (b) the amplitude modulated vibration due to Hopf bifurcation from the steady state subharmonic resonance of order 1/2 occur and then the chaotic vibration occur at two times of the major critical speed, (c) another chaotic vibration from the combination resonance occur at two times of the major critical speed. These experimental results match to the theoretical results (Part I).