A Weighted EFOR Algorithm for Dynamic Parametrical Model Identification of the Nonlinear System

Li, Yuqi; Yang, Dayong; Wen, Chuanmei

doi:10.3390/pr9122113

Cited by 2 publications

(1 citation statement)

References 30 publications

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“…On the other hand, a numerical representation model of the rotor-bearing system can be established based on a data-driven modeling method without any prior knowledge, except for the input and output data sets [15][16][17]. In the past decades, the data-driven modeling method is widely used for constructing the mathematical model to reveal the dynamic characteristics of nonlinear systems [18][19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Frequency Sweep Modeling Method for the Rotor-Bearing System in Time Domain Based on Data-Driven Model

Jin

Zhu

et al. 2022

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In practice, the modeling and analysis of nonlinear rotor-bearing systems are difficult due to the nonlinearity and complexity. In the previous studies, finite element simulation and mathematical modeling methods are mostly adopted to conduct the analysis. However, due to the time-consuming problem in finite element simulation and the lack of sufficient prior knowledge in mathematical modeling, the traditional method is difficult to establish the representation model. In order to overcome this issue, in this study, a data-driven model referred to as the NARX (Nonlinear Auto-Regressive with exogenous inputs) model is introduced to conduct the modeling and analysis of the rotor-bearing system. The identification of the NARX model requires random excitation as the system input, while the input signal of the rotor system is harmonics. Therefore, a time-domain frequency sweep modeling method is proposed in this paper by introducing the rotating speed into the coefficients function expression of the NARX model, the system output can be predicted according to the given speed. Moreover, the representation model of the rotor-bearing system obtained by using the proposed method is validated under different rotating speeds, the results show the applicability of the proposed modeling approach. Finally, an experimental case of the rotor-bearing test rig is demonstrated to show the application in practice. Both the numerical and experimental studies illustrate the applicability of the proposed modeling method, which provides a reliable model for dynamic analysis and fault diagnosis of the rotor-bearing system.

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Section: Introductionmentioning

confidence: 99%

Frequency Sweep Modeling Method for the Rotor-Bearing System in Time Domain Based on Data-Driven Model

Jin

Zhu

et al. 2022

Processes

Self Cite

View full text Add to dashboard Cite

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Bifurcation and Stability Analysis of a Bolted Joint Rotor System Contains Multi-Discs Subjected to Rub-Impact Effect

Wen

Jin

et al. 2022

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In aero-engines, the rotor systems are frequently designed with multistage discs, in which the discs are fastened together through bolted joints. During operation, rotating machines are susceptible to rotor–stator rubbing faults. Those bolted joints are subjected to friction and impact forces during a rubbing event, leading to a dramatic change in mechanical properties at the contacting interfaces, influencing the rotor dynamics, which have attracted the attention of scholars. In the present work, a mathematical model, which considers the unbalance force, rotor dimensional properties, nonlinear oil-film force and rub-impact effect, is developed to study the bifurcation and stability characteristics of the bolted joint rotor system containing multi-discs subjected to the rub-impact effect. The time-domain waveforms of the system are obtained numerically by using the Runge–Kutta method, and a bifurcation diagram, time domain waveforms, spectrum plots, shaft orbits and Poincaré maps are adopted to reveal the rotor dynamics under the effect of the rub-impact. Additionally, the influences of rubbing position at the multi-discs on rotor dynamic properties are also examined through bifurcation diagrams. The numerical simulation results show that the segments of the rotating speeds for rubbing are wider and more numerous, and the middle disc is subjected to the rub-impact. When the rub-impact position is far away from disc 1, the rubbing force has little effect on the response of disc 1. The corresponding results can help to understand the bifurcation characteristics of a bolted joint rotor system containing multi-discs subjected to the rub-impact effect.

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A Weighted EFOR Algorithm for Dynamic Parametrical Model Identification of the Nonlinear System

Cited by 2 publications

References 30 publications

Frequency Sweep Modeling Method for the Rotor-Bearing System in Time Domain Based on Data-Driven Model

Frequency Sweep Modeling Method for the Rotor-Bearing System in Time Domain Based on Data-Driven Model

Bifurcation and Stability Analysis of a Bolted Joint Rotor System Contains Multi-Discs Subjected to Rub-Impact Effect

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