Experimental Research On Dynamic Behavior Of A Rotor With Base Looseness/Rub Fault Under Bounded Noise Excitation

Rotor system plays an important role in the areas of transportation, energy and electricity, and its safe operation is related to the development of our national economy. Base looseness and rub are two kinds of rotor fault, which will directly affect the safe operation of the rotor system. Moreover, random excitation is an objective external interference factor for rotor systems, we can’t ignore its effect. It is of great significance to perform the experimental research on rotor systems with base looseness/rub fault under random excitation. The main work of this thesis is as follows:1. The models of the rotor systems with base looseness and rub coupled with looseness under random excitation are presented by the analysis of stochastic rotor systems, and the external random excitation is taken in the form of the bounded noise one. By the numerical simulation, samples of the excitation are generated.2. An experimental system for the rotor under the bounded noise excitation is designed and set up, the performance of the electromagnetic exciter is analyzed experimentally, and the mappings between the input signals and the output signals are modeled, which can provide a strong support for the experimental analysis on the dynamic behavior of a rotor system under the bounded noise excitation.3. Experimental studies are performed on the dynamic behavior of the rotor systems with base looseness and rub coupled with looseness under the bounded noise excitation, respectively. The dynamical evolution between the periodic-dominant, quasi-periodic-dominant and chaotic-dominant vibrations are discussed in detail by the bifurcation diagram, the orbit of shaft center, the Poincare’s mapping portrait, the frequency spectrogram and the time domain waveform, which can be acted as experimental basis upon further theoretical study on faulted rotor systems under random excitations.