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Hong Ying Hu

Bio: Hong Ying Hu is an academic researcher from Dalian Nationalities University. The author has contributed to research in topics: Hilbert–Huang transform & Span (engineering). The author has an hindex of 2, co-authored 2 publications receiving 6 citations.

Papers
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TL;DR: In this article, the effects of two cracks in shafts on dynamic characteristics of the rotor-bearing system are analyzed, along with the increase of the crack depth in first span, chaotic and periodic motions increase, and the quasi-periodic motion decrease in the supercritical rotate speed.
Abstract: The nonlinear dynamic model of two-span rotor-bearing system with two cracks in shafts is set up, and the effects of two cracks in shafts on dynamic characteristics of the rotor-bearing system are analyzed. Along with the increase of the crack depth in first span, the chaotic and periodic motions increase, and the quasi-periodic motion decrease in the supercritical rotate speed. There are harmonic elements of 1/4, 1/2 and 3/4 frequency division within the sub-critical speed range at different crack depths. There appears the frequency doubling resonance obviously when the crack depths are larger. Along with the increase of the crack depth in second span, the main influences to the responses of system are in the second span. The chaotic regions increase and then decrease and the periodic motions region increase in the sub-critical rotate speed range.

4 citations

Journal ArticleDOI
TL;DR: According to wavelet regression estimation method, a new regression function estimation method based on EMD is presented and the simulation proves the advantages of the approach with easy computation and more accurate result.
Abstract: Empirical Mode Decomposition (EMD) is a non-stationary signal processing method developed recently. It has been applied in many engineering fields. EMD has many similarities with wavelet decomposition. But EMD Decomposition has its own characteristics, especially in accurate trend extracting. Therefore the paper firstly proposes an algorithm of extracting slow-varying trend based on EMD. Then, according to wavelet regression estimation method, a new regression function estimation method based on EMD is presented. The simulation proves the advantages of the approach with easy computation and more accurate result.

2 citations


Cited by
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TL;DR: A flexible Bayesian nonparametric model for test equating which allows the use of covariates in the estimation of the score distribution functions that lead to the equating transformation is proposed and may change as a function of the covariates.

11 citations

Journal ArticleDOI
TL;DR: In this paper, a nonlinear dynamic model of a two-span rotor system is constructed based on the Hamilton principle and the finite element method, where the Musznyska model and the short bearing model are employed to describe the nonlinear seal force and oil-film force.
Abstract: A nonlinear dynamic model of a two-span rotor system is constructed based on the Hamilton principle and the finite element method. The Musznyska model and the short bearing model are employed to describe the nonlinear seal force and oil-film force. The fourth-order Runge-Kutta method is used to calculate the numerical solutions. The bifurcation diagrams, time-history diagrams, phase trajectories, and Poincare maps are presented to analyze the dynamic behavior of the bearing center and the disk center in the horizontal direction. The numerical results indicate that the rotational speed, the nonlinear seal force, the oil-film force, and the stiffness of the coupling have a significant effect on the stability of the rotor system. The dynamic behavior of the two-span rotor system is more complicated when impacted by the nonlinear seal force and oil-film force.

1 citations

Journal Article
TL;DR: In this article, the nonlinear coupled vibrations of a rotor with two cracks were investigated by numerical simulated method, the stiffness matrix of cracked element is deduced by fracture mechanics principle and FEM(finite element method), the opening or closing of cracks depend on the stresses acting on the cross section where crack located.
Abstract: Rotor crack is one of the frequent faults in rotor machine. The nonlinear coupled vibrations of a rotor with two cracks were investigated by numerical simulated method. The stiffness matrix of cracked element is deduced by fracture mechanics principle and FEM(finite element method), the opening or closing of cracks depend on the stresses acting on the cross section where crack located. The dynamic responds of two-crack rotor with angle between them be 0°, 90° and 180° are analyzed in both time domain and frequency domain. It is concluded the coupled axial and torsion vibration are excited by lateral forces due to crack. The angle between two cracks had obvious effects on the harmonic components, amplitude and rotor orbits of rotor vibration.

1 citations