Dynamic Characteristics and Experimental Research of Dual-Rotor System with Rub-Impact Fault

Xu, Hongyan; Wang, Nanfei; Jiang, Dongxiang; Han, Te; Li, Dewang

doi:10.1155/2016/6239281

Cited by 17 publications

(18 citation statements)

References 15 publications

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“…e effects of rotational speed, imbalance, damping coefficient, and friction coefficient on the response of the microrotor system were evaluated. Xu et al [9] studied the rubbing failure model of rotor system, considering the elastic deformation, contact penetration, and elastic damping support during friction.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Characteristics and Experimental Research of a Two‐Span Rotor‐Bearing System with Rub‐Impact Fault

Zhu

Wang

Han

et al. 2019

Shock and Vibration

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Rotor rub-impact has a great influence on the stability and safety of a rotating machine. This study develops a dynamic model of a two-span rotor-bearing system with rubbing faults, and numerical simulation is carried out. Moreover, frictional screws are used to simulate a rubbing state by establishing a set of experimental devices that can simulate rotor-stator friction in the rotor system. Through the experimental platform and its analysis system, the rubbing experiment was conducted, and the vibration of the rotor-bearing system before and after the critical speed is observed. Rotors running under normal condition, local slight rubbing, and severe rubbing throughout the entire cycle are simulated. Dynamic trajectories, frequency spectrum diagrams, chart of axis track, and Poincare maps are used to analyze the features of the rotor-bearing system with rub-impact faults under various parameters. The vibration characteristics of rub impact are obtained. Results show that the dynamic characteristics of the rotor-bearing system are affected by the change in velocity and degree of impact friction. The findings are helpful in further understanding the dynamic characteristics of the rub-impact fault of the two-span rotor-bearing system and provide reference for fault diagnosis.

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Section: Introductionmentioning

confidence: 99%

Dynamic Characteristics and Experimental Research of a Two‐Span Rotor‐Bearing System with Rub‐Impact Fault

Zhu

Wang

Han

et al. 2019

Shock and Vibration

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“…Its specific solving method will be mentioned in [12]. On the basis of the system NOFRFs acquired, the frequency domain output of the system can be rewritten as…”

Section: Theory Of Nofrfsmentioning

confidence: 99%

“…According to the method mentioned in [12], when two harmonics with different intensities but the same frequency are used to excite the system, the first four orders of NOFRFs can be obtained, namely, G 1 (jω), G 2 (jω), G 3 (jω), G 3 (j3ω), G 4 (j2ω), and G 4 (j4ω). ey can be used directly for fault detection, and they can be further extracted from fault features.…”

Section: Theory Of Nofrfsmentioning

confidence: 99%

“…en, two vibration responses with di erent excitation strengths but the same excitation frequency can be obtained only by changing the imbalance and solving again. According to equation (9) and [12], the rst four orders of NOFRFs of the system can be obtained by the two inputs and Shock and Vibration outputs of the system.…”

Section: Estimation Of Nofrfs Of Rotor-stator Rub-impactmentioning

confidence: 99%

“…Researchers found that the frequency domain output of the system will have nonlinear phenomena [11,12], such as harmonics, intermodulation, and so on when the mechanical system is damaged. However, the knowledge of the linear method cannot explain the generation of nonlinear phenomena [13].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Research on Fault Feature Extraction Method Based on NOFRFs and Its Application in Rotor Faults

Liu

Zhao

et al. 2019

Shock and Vibration

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Rub-impact between the rotating and static parts is a more common fault. The occurrence of faults is often accompanied by the generation of nonlinear phenomena. However, it is difficult to find out because the nonlinear characteristics are not obvious at the beginning of the fault. As a new frequency domain-based method, nonlinear output frequency response functions (NOFRFs) use the vibration response to extract the nonlinear characteristics of the system. This method has a better recognition rate for fault detection. Also, it has been applied in structural damages detection, but the high-order NOFRFs have the characteristics that the signals are weak and the features are difficult to extract. On this basis, the concept of the weighted contribution rate of the NOFRFs is proposed in this paper. The variable weighted coefficients with orders are used to amplify the influence of high-order NOFRFs on the nonlinearity of the system so as to extract its fault characteristics. The new index RI is proposed based on Clenshaw–Curtis quadrature formula to eliminate the effect of artificially selected weighted coefficients on sensitivity. Especially in the early stage of the fault, the new index varies greatly with the deepening of the fault. Both simulation and experimental results verify the validity and practicability of the new index. The new index has certain guiding significance in the detection of mechanical system faults.

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Research nonlinear vibrations of a dual-rotor system with nonlinear restoring forces

Liu

Wang

Luo

2020

J Braz. Soc. Mech. Sci. Eng.

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A dual-rotor system is a core component of an aero-engine, and it is very important to study the nonlinear vibrational characteristics for the aero-engine's development. Based on analyzing structural characteristics of aero-engine's rotors, a novel and more practical dual-rotor dynamic coupling model with nonlinear restoring forces of high-pressure and low-pressure rotors is first proposed. In the linear dynamic coupling model, the coupling critical speed, natural frequencies and vibration responses of the low-pressure rotor are analyzed systematically. In the nonlinear dynamic coupling model, the vibrational characteristics of the dual-rotor system with different nonlinear parameters are simulated numerically based on the nonlinear dynamic theory. The improved shooting method combined the harmonic balance method, and the genetic algorithm is proposed to calculate theoretical solutions of the nonlinear dynamic coupling model. The stability of theoretical solutions is investigated by the Floquet theory. The research results show that the dual-rotor system appears very complicated nonlinear vibrations such as nonlinear multitudinal solutions, double period motions, almost periodic motions and chaotic motions. The transition between nonlinear vibrations occurs suddenly.

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Dynamic Characteristics and Experimental Research of Dual-Rotor System with Rub-Impact Fault

Cited by 17 publications

References 15 publications

Dynamic Characteristics and Experimental Research of a Two‐Span Rotor‐Bearing System with Rub‐Impact Fault

Dynamic Characteristics and Experimental Research of a Two‐Span Rotor‐Bearing System with Rub‐Impact Fault

Research on Fault Feature Extraction Method Based on NOFRFs and Its Application in Rotor Faults

Research nonlinear vibrations of a dual-rotor system with nonlinear restoring forces

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