Weighted contribution rate of nonlinear output frequency response functions and its application to rotor system fault diagnosis

• Published in: Journal of sound and vibration Vol. 460; p. 114882
• Main Authors: Liu, Yang, Zhao, Yulai, Lang, Zi-Qiang, Li, Jintao, Yan, Xinxin, Zhao, Siyao
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 10.11.2019; Elsevier Science Ltd
• Subjects: Bearings; Cracked rotor; Cracking (fracturing); Criteria; Damage detection; Fault detection; Fault diagnosis; Fracture mechanics; Frequency analysis; Frequency response functions; Industrial applications; Machinery; NOFRFs; Nonlinear analysis; Nonlinear response; Nonlinear systems; Rotating machinery; Rotors; Signal processing; Vibration; Vibration signal; Weighted contribution rate; Fault diagnosis; Cracked rotor; Weighted contribution rate; NOFRFs; Vibration signal
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2019.114882

Rotor cracking is a common fault in rotating machinery, that can often be detected based on the vibrations of such machinery. Therefore, many vibration signal based techniques have been developed for rotor fault detection. However, signal based fault diagnosis is often affected by noise and cannot be used to fully quantify the operating conditions of rotors, which are often more relevant to rotor structural characteristics compared to vibration behaviours. Nonlinear output frequency response functions (NOFRFs) represent a nonlinear system frequency analysis approach that was proposed to address challenges associated with applying signal based fault detection. NOFRFs have a wide range of applications in industry, including rotor fault diagnosis. In this study, a novel NOFRFs based criterion called the weighted contribution rate of NOFRFs is proposed to enhance the capability of the NOFRFs based rotor crack detection and quantification. The proposed criterion can amplify the impact of rotor characteristics that are sensitive to rotor cracks, which considerably improves the crack diagnosis performance. The effectiveness and advantages of the proposed rotor damage detection method are verified both experimentally and through simulations, demonstrating its potential applications in the early stages of rotor crack diagnosis. Only the vibration signal of the cracked rotor at two speeds are need to be measured. The index K proposed based on the weighted contribution rate of nonlinear output frequency response functions method can be got with the vibration signal. The values of K of the faulty rotor and the normal rotor are compared with each other to realize fault diagnosis. [Display omitted] •The weighted contribution rate of NOFRFs significantly enhance the capability of the NOFRFs.•The new criterion is able to amplify the impacts of the rotor faults characteristics.•The weighted contribution rate of NOFRFs highly sensitive to the early development of faults.