Article
Engineering, Electrical & Electronic
Rui Wang, Yuefang Wang, Xiaojian Cao, Shuhua Yang, Xinglin Guo
Summary: In this study, the response surface of the Muszynska nonlinear seal force model coefficient was obtained using CFD combined with the RBF method. By conducting rotor dynamics analysis with varying parameters, a new approach for analyzing the nonlinear characteristics of rotor-bearing-seal systems was proposed, leading to different system speeds compared to traditional methods.
Article
Thermodynamics
Mo Yang, Hao Xuan, Tao Qin, Yikun Wang, Yuebin Zhou, Wen Zhang
Summary: This paper presents a nonlinear dynamic analysis of a composite rotor-bearing system with pedestal looseness, considering the nonlinear oil film force and the pedestal looseness. The results indicate that the stiffness and damping coefficients of a composite shaft tube can be strongly influenced by the laminate parameters, affecting the instability speed of the rotor system. To enhance the oil film instability speed, maximizing the ratio of the small orientation angle layer or the ±45° layer is essential. The research results have important theoretical value for the design of composite rotor-bearing systems.
ADVANCES IN MECHANICAL ENGINEERING
(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
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
Engineering, Mechanical
Pengfei Wang, Hongyang Xu, Hui Ma, Hongzheng Han, Yang Yang
Summary: This paper analyzes the effects of axial, radial, and tilt misalignments on the dynamic characteristics of the planetary gear set-rotor system. It proposes a nonlinear restoring force model for ball bearings under different misalignment conditions. The dynamic model of the planetary gear set is established using the lumped parameter method, and the rotor is modeled using the Timoshenko beam element. The results show that misalignments reduce vibration amplitude but increase load-bearing area and contact load. Different types of misalignments also affect the varying compliance frequency amplitude of the bearing. The research provides a theoretical basis for fault diagnosis and identification of bearing misalignment in complex rotating machinery systems.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
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
Automation & Control Systems
Mahboubeh Asadi Varnusfaderani, Mostafa Irannejad Parizi, Masoud Hemmatian, Abdolreza Ohadi
Summary: Magnetorheological fluid is an effective smart fluid used for vibration control. In this study, analytical tools and algorithms are presented for identifying the parameters of flexible rotor systems equipped with MR squeeze-film dampers. The developed algorithm and finite element model are shown to accurately identify the system parameters.
Article
Computer Science, Interdisciplinary Applications
Joon Ha Jung, Myungyon Kim, Jin Uk Ko, Hyeon Bae Kong, Byeng D. Youn, Kyung Ho Sun
Summary: This paper proposes label-based, mini-batch methods for convolutional neural network based diagnosis of fluid-film bearing rotor systems and compares their performance to conventional random mini-batch methods. The case study results indicate that the equally labeled mini-batch approach shows the best performance.
COMPUTERS IN INDUSTRY
(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
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
Acoustics
Jing Liu, Changke Tang, Guang Pan
Summary: This paper proposes a comprehensive numerical dynamic model of a flexible-rotor bearing system based on nonlinear contact force methods, analyzing the influences on system displacements and spectrums. Results show that differences in frequency-amplitude characteristics between flexible and rigid rotor bearing systems are small at low speeds but significant at high speeds.
JOURNAL OF VIBRATION AND CONTROL
(2022)
Article
Engineering, Mechanical
Zhou Sun, Siyu Chen, Zehua Hu, Duncai Lei
Summary: Thermal effects play a crucial role in the failure of gear systems, impacting the system motion from periodic to chaotic with temperature increase. Proper backlash and bearing type can mitigate the effects of temperature on the system.
NONLINEAR DYNAMICS
(2022)
Article
Engineering, Mechanical
Jie Yang, Rupeng Zhu, Yanjiong Yue, Guanghao Dai, Xunmin Yin
Summary: The influence of surface waviness on the dynamic characteristics of the journal bearing-herringbone gear rotor system is investigated. A coupling dynamic model is proposed, which considers the bearing waviness, time-varying meshing stiffness, gear backlash, and flexible shaft. Results suggest that the appropriate bearing waviness contributes to the stability of the system.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Siyuan Zhang, Jin Zhou, Haitong Wu, Yue Zhang
Summary: This study investigates the influence of Alford force on a permanent magnet turbo-expander/generator supported by active magnetic bearings. The results show that adjusting the control parameters can mitigate the impact of Alford force, with particular attention needed on the differential coefficient.
JOURNAL OF VIBRATION ENGINEERING & TECHNOLOGIES
(2021)
Article
Engineering, Mechanical
Dongil Shin, Junho Suh, Alan B. Palazzolo
Summary: This paper investigates the asymmetric temperature-induced thermal bow vibration of a rotor supported by a flexure pivot journal bearing (FPJB). The effects of FPJB design parameters on the vibration are explored. The developed structural and thermal finite element models are validated by comparing the predicted response with experimental results. The results demonstrate the significant impact of FPJB parameter values on the severity and speed range of the thermal bow-induced vibration.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
Huiyi Yang, Yang Xu, Chao Xu
Summary: This study focuses on the impact of dry friction interfaces on the dynamics of jointed structures, particularly on the statistics of contact pressure distribution. Through experimental and simulation analysis, it is found that surface roughness and contact load have significant effects on contact area, contact stiffness, and mean contact pressure.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Guanglan Hu, Houfu Dai
Summary: The effect of metal coating on the machinability of cubic silicon carbide was investigated using molecular dynamics simulation. The results showed that the type of coating has a significant impact on cutting force, surface morphology, stress, and tool wear. Among the three metals studied, Cu coating had the greatest impact on improving cutting performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Yunfan Liu, Guozheng Ma, Lina Zhu, Cuihong Han, Zhen Li, Bin Zhang, Haichao Zhao, Haidou Wang, Shuying Chen
Summary: The service performance of coated self-lubricating spherical plain bearings can be improved by applying self-lubricating coatings, especially double-sided coatings. The presence of a large-area and complete mixed friction transfer film on the contact surfaces can cause a signal downstage before the signal mutation stage.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Yakup Artun, C. Oktay Azeloglu, Gokhan Taylan
Summary: This article investigates the tribological properties of polymer journal bearings, particularly focusing on radial journal bearings made from UHMWPE and POM materials with different surface qualities. The study examines the performance of these bearings under varying load and speed conditions, and analyzes the relationship between material and surface roughness in tribological performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
