A novel diagnosis indicator for rub-impact of rotor system via energy method

Zhang, Xiantao; Yang, Yue; Ma, Hui; Shi, Mingming; Wang, Ping

doi:10.1016/j.ymssp.2022.109825

Cited by 28 publications

(5 citation statements)

References 45 publications

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“…Song et al [4] studied the nonlinear dynamic behaviors of an aviation engine drum with the rubbing-impact faults of the rotor and stator blades, and the theoretical research results were confirmed by experiments. A new method for identifying the rubbing faults of the rotor system by energy characteristics was proposed by Zhang et al [5]. Xu et al [6] studied the vibrational characteristics of the spindle-bearing-housing-belt system with rub-collision by the means of the theoretical modeling method and FEA, and the results showed that the dynamic parameters of the belt have little effect on the vibrational response of the system.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Analysis of Three-Rotor System with Hollow Shaft under Clutch Misalignment

Nan,

Wang,

2024

Aerospace

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Rotor system of aviation engines is often made of multiple rotors connected by the clutch. Due to manufacturing and assembly errors, there is a clutch misalignment, including the parallel misalignment and the angle misalignment. This misalignment produces additional torque in the operation of the system, leading to an abnormal increase in its oscillation, which causes the rubbing between the stator and the rotor. The rub-collision poses great harm to the safety and stability of the aero-engine. The analytical model of the rotor system with misalignment and rubbing faults is established, and the influence of the rotational speed, the misalignment, and the rubbing on the nonlinear characteristics of the rotor is investigated. Considering the nonlinear Hertz contact force and bearing gap, the model of the inter-shaft bearing is built; the parallel and angle misalignments of clutch are taken into account to analyze the characteristic frequency of the faults. For raising the thrust-to-weight ratio of aviation engines, the hollow shaft is often adopted, and the effect of the wall thickness for the shaft on the nonlinear vibration of the system is also investigated. It is innovative to study the transfer mechanism from wall thickness to the nonlinear vibrational responses of the overall structure. The result indicates that, with the increase in the wall thickness of the shaft, the second critical rotating speed increases, while the first critical rotating speed is almost unchanged. The characteristic frequencies for the three-rotor system with coupling faults are obtained. Despite intuition, the parallel misalignment can inhibit rub-collision vibration to a certain extent. The research has important reference values for the fault recognition and structural optimization of the three-rotor system.

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Section: Introductionmentioning

confidence: 99%

Dynamic Analysis of Three-Rotor System with Hollow Shaft under Clutch Misalignment

Nan,

Wang,

2024

Aerospace

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“…With the reduction of space between rotors and stators in large machinery, such as aero engines, the likelihood of rubbing faults occurring has significantly increased [1]. Rotorstator rubbing faults, as a typical secondary fault in rotating machinery, pose a great risk to the normal operation of the equipment [2]. Therefore, accurate detection of rubbing faults is important to ensure the safe and efficient operation of equipment [3].…”

Section: Introductionmentioning

confidence: 99%

A new method of noise reduction grounded on the Hankel matrix and its application in rubbing fault diagnosis

Zhang,

Yu,

Feng

et al. 2024

Meas. Sci. Technol.

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In processing signals with singular value decomposition (SVD), one of the keys lies in building an appropriate Hankel matrix from signals. To address the difficulty in extracting the feature information of rubbing faults between rotor and stator, by taking advantage of the nature of rubbing fault information closely related to the rotation period of equipment, a new method of SVD is presented according to the Hankel matrix built from the periodicity of rotation machine. Firstly, with the periodicity of rub-impact fault as the basis, the interval step size between Hankel vectors was determined to self-adaptively build a Hankel matrix of signal. Secondly, the newly-built Hankel matrix was denoised through singular value differential spectrum (SVDS). Thirdly, to reduce the loss of data as much as possible, a strategy was proposed to rebuild signals according to the first and last rows of denoised signals. Fourthly, features of rubbing faults were extracted according to the frequency spectrum of reconstructed signals and faults were identified. To verify the applicability and effectiveness of presented algorithm, various types of simulation signals and tester signals from different states were brought in; meanwhile, the presented algorithm was compared with a variety of classical methods. The result proves that the proposed method not only can effectively restrain noise interference, but also highlight fault feature information and correctly identify rub-impact faults.

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“…Using energy flow theory, Zhang et al [45] developed a PFA-based diagnostic index for rotor systems with rub-impact faults and identified a relationship between input power and rub-impact. Shi et al [46] investigated vibration transmission through nonlinear joints in coupled systems based on PFA, revealing the vibrational energy flow mechanism within the jointed structures.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear vibration isolation performance enhancement using elastic constraint and linkage mechanism

Dai,

Xu,

Wang

et al. 2024

Preprint

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This research presents nonlinear vibration isolators with elastic constraint included in linkage mechanism with geometry nonlinearity. The vibration attenuation enhancement of integrating nonlinear elements to a single-stage isolation system and an isolation system with flexible foundation considering the applications in marine engineering or aerospace engineering is investigated. The harmonic balance method (HBM) with the Alternating Frequency/Time (AFT) scheme and a time-marching method are employed to calculate responses. The vibration transmissibilities and power transmission indices are taken as measures of isolation performance. The results show that the nonlinear isolator dramatically decreases power flow and vibration transmissibility to the base in a broad frequency range. The use of the elastic constraint enables wider ranges of parameters of spring-linkage in design and the proposed isolator can provide improved vibration attenuation capabilities in low frequencies. By a collaborative design using the elastic constraint and linkage mechanism, the peaks in curves force transmission and power flow to the flexible foundation can be significantly suppressed and shifted towards lower frequencies. The study demonstrates that the proposed isolator designs can be further applied in the isolation platform of mechanical systems on board.

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A novel diagnosis indicator for rub-impact of rotor system via energy method

Cited by 28 publications

References 45 publications

Dynamic Analysis of Three-Rotor System with Hollow Shaft under Clutch Misalignment

Dynamic Analysis of Three-Rotor System with Hollow Shaft under Clutch Misalignment

A new method of noise reduction grounded on the Hankel matrix and its application in rubbing fault diagnosis

Nonlinear vibration isolation performance enhancement using elastic constraint and linkage mechanism

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