Article
Mechanics
Pengfei Wang, Hongyang Xu, Hui Ma, Yang Yang, Qingkai Han, Bangchun Wen, Xiaopeng Li
Summary: A rotor dynamic model with bearing dynamic misalignment is established to study the nonlinear vibration problem caused by the dynamic misalignment of rolling bearings in rotating machinery. The effects of single and two bearings' dynamic misalignment and the phase relationship of two dynamic misalignment bearings on the rotor vibration characteristics are investigated. Furthermore, the influence of bearing clearance, raceway curvature radius, ball number, and radial load on the nonlinear vibration response of the dynamic misalignment bearing-unbalance rotor system is analyzed. The results indicate that dynamic misalignment can excite vibration at twice the rotor frequency, increase resonance speed, and enhance the rotor's hardening-type nonlinearity characteristics. The influence of out-of-phase dynamic misalignment on rotor resonance is greater than that of in-phase misalignment. The system stability can be improved by reducing bearing clearance and increasing the curvature radius coefficient. The vibration caused by bearing dynamic misalignment can be reduced by selecting bearings with more balls and appropriately increasing the bearing load.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Engineering, Multidisciplinary
Hongchuan Cheng, Yimin Zhang, Wenjia Lu, Zhou Yang
Summary: A mathematical model is presented to study the dynamic properties of rotor-bearing coupling system under various effects, and the impact of typical parameters on the mechanical characteristics of the rotor system is analyzed. The results offer theoretical support for controlling the rotor-bearing system and studying the nonlinear vibration mechanism in practical applications.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Mechanics
Zhenyong Lu, Shun Zhong, Huizheng Chen, Xiaodong Wang, Jiajie Han, Chao Wang
Summary: This study focuses on the nonlinear behaviors of a dual-rotor system supported by a rolling element bearing, discussing the time-varying stiffness and primary resonance behaviors affected by the ball bearing parameters. The results show that the mean values of the equivalent stiffness of the system and the rotation speed for forced resonance decrease as the clearance of the ball bearing increases.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2021)
Article
Engineering, Multidisciplinary
Zeyuan Chang, Lei Hou, Yushu Chen
Summary: This paper investigates the nonlinear dynamics and thermal bidirectional coupling characteristics of a rotor-ball bearing system. The motion equations of the rotor system are formulated considering the thermal effects on the radial clearance of the ball bearing. A heat transfer model, incorporating the frictional heat generation induced by the ball bearing's dynamic load, is established and coupled with the motion equations. The results demonstrate that the thermal expansion of the ball bearing affects the dynamics and thermal characteristics of the system, while the nonlinear dynamic response of the rotor leads to nonlinear thermal characteristics of the ball bearing.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Engineering, Mechanical
Zhongliang Xie, Jian Jiao, Kang Yang, Tao He, Rugang Chen, Weidong Zhu
Summary: The high temperature liquid Lead-Bismuth (PbBi) solution lubricated bearing plays a crucial role in the two-circuit main loop system of nuclear power stations. This study developed revised dynamic lubrication models considering cavitation effects and investigated the influences of clearances, rotating speeds, eccentricity ratios, and annular guiding grooves on the hydrodynamic characteristics. The results confirm the relationship between peak pressure, speeds, and eccentricity ratios, as well as the impact of clearances on maximum/minimum pressure. Theoretical analysis coincided with experimental data, verifying the rationality and correctness of the lubrication models.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Mo Shuai, Zhang Yingxin, Song Yuling, Song Wenhao, Huang Yunsheng
Summary: The nonlinear dynamic model of the non-orthogonal face gear-rotor-bearing system was established in this study, considering the influence of nonlinear features such as time-varying meshing stiffness, transmission error, tooth backlash, bearing clearance, and collision force and friction between tooth. The effects of excitation frequency, friction coefficient, and support stiffness on the dynamic characteristic of the system were analyzed using various methods. The results revealed that the non-orthogonal gear-rotor-bearing transmission system exhibits a variety of nonlinear characteristics, and the parameters of the system should be controlled to ensure stability and prevent amplitude mutation.
NONLINEAR DYNAMICS
(2022)
Article
Acoustics
Sha Li, Yanjun Lu, Yongfang Zhang, Hongbo Luo, Song Wang, Xuanen Kan
Summary: This study investigates the dynamic characteristics of an asymmetric rotor system supported in axial-grooved gas-lubricated bearings. A hybrid numerical model is established for effectively solving the nonlinear dynamic responses of the rotor system. The study reveals complex nonlinear dynamic phenomena and specific bifurcation characteristics in the asymmetric rotor system.
JOURNAL OF LOW FREQUENCY NOISE VIBRATION AND ACTIVE CONTROL
(2022)
Article
Engineering, Mechanical
Kang Zhang, Kai Feng, Wenjun Li, Lijun Song
Summary: The study presents a numerical model that efficiently reflects the actual mechanical properties of O-rings and the coupling between aerodynamic and aerostatic effects on the performance of a rotor-PAJB system. The model is well verified by experimental results, showing the significant impact of O-ring material and quantity on the stability of the system.
NONLINEAR DYNAMICS
(2022)
Article
Acoustics
Felipe Carmo Carvalho, Marcus Fernandes de Oliveira, Fabian A. Lara-Molina, Aldemir A. Cavalini, Valder Steffen
Summary: This paper focuses on the design of robust controllers applied to supercritical rotors supported by active magnetic bearings, demonstrating their effectiveness through theoretical and experimental tests. The optimal design procedure tunes the robust neuro-fuzzy controller to balance vibration attenuation performance and robustness.
JOURNAL OF VIBRATION AND CONTROL
(2021)
Article
Acoustics
Tianzhu Wang, Qian Ding
Summary: This paper investigates the modal balancing method for a rotor-bearing system based on nonlinear normal modes (NNMs). The proposed algorithm includes three steps: computing NNMs and expressing nonlinear modal shapes using complex Fourier series, describing unbalance response as a complex amplitude with higher harmonics, and estimating correction coefficients for each harmonic to obtain total unbalance corrections. Hertz contact force and different radial internal clearances of the ball bearings are considered in the balancing simulation. The accuracy and effectiveness of the proposed method are demonstrated by comparing the responses after balancing with NNMs and the linear modal method.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Metallurgy & Metallurgical Engineering
Peng-fei Wang, Yang Yang, Hong-yang Xu, Hui Ma, Qing-kai Han, Zhong Luo, Bang-chun Wen
Summary: In this study, a five-degree of freedom nonlinear force model considering bearing misalignment is proposed, and the effects of misalignment on the dynamic contact characteristics of bearing and the vibration characteristics of the rotor system are analyzed. Evaluation indexes for bearing misalignment are given based on the dynamic response. The research provides valuable insights for fault identification of the rotor-bearing system.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2023)
Article
Engineering, Mechanical
Christoph Baum, Hartmut Hetzler, Simon Schroeders, Tim Leister, Wolfgang Seemann
Summary: A novel physical and mathematical model of foil air bearings was developed with a focus on computational time-efficiency for rotor dynamic investigations. The model, which accounts for nonlinear deformation behavior and linear viscous damping, was validated using published experimental data and reduction technique, showing a decrease in computation time up to a factor of 1000 with a slight loss in accuracy. The bearing model was also coupled with a rigid rotor model to demonstrate its applicability during a run-up and coast-down.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Mechanics
Sai Zhang, Yeyin Xu, Runchao Zhao, Yinghou Jiao, Zhaobo Chen
Summary: In this paper, a nonlinear finger seal force model considering the interaction between the feet of adjacent laminates is established. The effects of rotational speed, eccentricity, pressure difference, and the number of seal laminates on the system are studied. High-order independent nonlinear vibrations are discovered, and their detailed nonlinear mechanisms are revealed.
INTERNATIONAL JOURNAL OF APPLIED MECHANICS
(2023)
Article
Acoustics
Dyah Kusuma Dewi, Zainal Abidin, Bagus Budiwantoro, Jhon Malta
Summary: This paper is focused on studying scale-fullscale models of rotor-bearing systems on rotating conditions. The gyroscopic effect causing forward and backward whirl frequencies is investigated. The experimental study validates the scaling factor of whirl frequencies and the impact of the gyroscopic effect on the first bending natural frequency. The findings have important implications for engineers in the implementation of scaling methods in rotating machinery design.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Engineering, Mechanical
Jianbo Zhang, Dongjiang Han, Zhongliang Xie, Chao Huang, Zhushi Rao, Mingbo Song, Zhimin Su
Summary: In this paper, a dynamic model of the aerostatic bearing-rotor system is established to investigate the influences of rotational speed, unbalance, rotor mass, and supply pressure on the nonlinear behaviors of the system. The results demonstrate various nonlinear phenomena, including periodic and quasi-periodic motions. Additionally, it is found that proper adjustments of the unbalance, rotor mass, and supply pressure can control the nonlinear vibration and enhance system stability.
TRIBOLOGY INTERNATIONAL
(2022)
