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coupling vibration analysis of high-speed maglev train-viaduct systems with control loop failure

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Journal of Central South University 2022年第8期29卷 2771-2790页

作者： GUO Wei CHEN Xue-yuan YE Yi-tao HU Yao LUO Yi-kai SHAO Ping HUANG Ren-qiang WANG Xu-yixin GUO Zhen TAN Sui School of Civil Engineering Central South UniversityChangsha 410075China National Engineering Research Center of High-speed Railway Construction Technology Changsha 410075China Engineering Technology Research Center for Prefabricated Construction Industrialization of Hunan Province Changsha 410075China CCCC Highway Consultants Co. Ltd.Beijing 100088China School of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China

The risk of failure of the control loop can occur when a high-speed maglev train runs on ***,the failure of the levitation magnets which balances the gravity of the maglev train could cause the train collision with *** study the dynamic response of the train and the viaduct when the levitation magnet control loop failure occurs,a high-speed maglev train-viaduct coupling model,which includes a maglev controller fitted by measured force-gap data and considers the actual structure of train and viaduct,is *** the accuracy and effectiveness of the established approach are validated by comparing the computed dynamic responses and frequencies with the measurement *** that,the dynamic responses of maglev train and viaduct are discussed under normal operation and control loop failures,and the most disadvantageous combination of control loop failures is *** results show that when a single control loop fails,it only has a great influence on the failed electromagnet,and the maglev response of adjacent electromagnets has no obvious change and no collision *** there is a risk of rail collisions when the dual control loop fails.

关键词： high-speed maglev train control loop failure coupling vibration maglev control

A comprehensive review on coupling vibrations of train-bridge systems under external excitations

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Railway Engineering Science 2022年第3期30卷 383-401页

作者： Yongle Li Huoyue Xiang Zhen Wang Jin Zhu Department of Bridge Engineering Southwest Jiaotong UniversityChengdu 610031China Wind Engineering Key Laboratory of Sichuan Province Chengdu 610031China

In recent years,high-speed railways in China have developed very rapidly,and the number and span of the railway bridges are keeping ***,frequent extreme disasters,such as strong winds,earthquakes and floods,pose a significant threat to the safety of the train–bridge ***,it is of paramount importance to evaluate the safety and comfort of trains when crossing a bridge under external *** these aspects,there is abundant research but lacks a literature ***,this paper provides a comprehensive state-of-the-art review of research works on train–bridge systems under external excitations,which includes crosswinds,waves,collision loads and seismic *** characteristics of external excitations,the models of the train–bridge systems under external excitations,and the representative research results are summarized and ***,some suggestions for further research of the coupling vibration of train–bridge system under external excitations are presented.

关键词： Train-bridge system coupling vibration Crosswind Wave Collision loads Seismic load

Seismic response analysis of road vehicle-bridge system for continuous rigid frame bridges with high piers

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Earthquake Engineering and Engineering vibration 2012年第4期11卷 593-602页

作者： Li Yongle Chen Ning Zhao Kai Liao Haili Department of Civil Engineering Southwest Jiaotong University CCCC Highway Consultants CO. Ltd.

The objective of this study is to investigate the effects of earthquakes on road vehicle-bridge coupling vibration systems. A two-axle highway freight vehicle is treated as a 13 degree-of-freedom system composed of several rigid bodies, which are connected by a series of springs and dampers. The framework of the earthquake-vehicle-bridge dynamic analysis system is then established using an earthquake as the extemal excitation. The equivalent lateral contact force serves as the judgment criteria for sideslip accidents according to reliability theory. The entire process of the vehicle crossing the bridge is considered for a very high pier continuous rigid frame bridge. The response characteristics of the vehicle and the bridge are discussed in terms of various parameters such as earthquake ground motion, PGA value of the earthquake, incident angle, pier height, vehicle speed and mass. It is found that seismic excitation is the most influential factor in the responses of the vehicle-bridge system and that the safety of vehicles crossing the bridge is seriously impacted by the dual excitations of earthquake and bridge vibration.

关键词： vehicle-bridge system coupling vibration seismic effects safety dynamic response

Nonlinear Dynamic Characteristic Analysis of the Shaft System in Water Turbine Generator Set

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Chinese Journal of Mechanical Engineering 2009年第1期22卷 124-131页

作者： MA Zhenyue SONG Zhiqiang School of Civil and Hydraulic Engineering Dalian University of Technology Dalian 116023 China

A 3D finite element vibration model of water turbine generator set is constructed considering the coupling with hydropower house foundation. The method of determining guide bearing dynamic characteristic coefficients according to the swing of the shaft is proposed, which can be used for studying the self-vibration characteristic and stability of the water turbine generator set. The method fully considers the complex supporting boundary and loading conditions; especially the nonlinear variation of guide bearing dynamic characteristic coefficients and the coupling effect of the whole power-house foundation. The swing and critical rotating speed of an actual generator set shaft system are calculated. The simulated results of the generator set indicate that the coupling vibration model and calculation method presented in this paper are suitable for stability analysis of the water turbine generator set.

关键词： water turbine generator set dynamic characteristic coefficients nonlinearity coupling vibration critical speed

Dynamic performance analysis of a seismically isolated bridge under braking force

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Earthquake Engineering and Engineering vibration 2012年第1期11卷 35-42页

作者： Yu Fang Wen Liuhan·heisha Zhou Fulin Ye Lieping Department of Civil Engineering Tsinghua University Beijing 100084 China Shenzhen Municipal Design and Research Institute Co. limited Shenzhen 518029 China Earthquake Engineering Research ＆ Test Center of Guangzhou University Guangzhou 510405 China

In order to study the dynamic performance of seismically isolated bridges under the most unfavorable loads in the longitudinal direction, a dynamic equation for vehicle braking in the longitudinal direction is established. A four or five- order Runge-Kutta method is adopted to obtain the time-history response of a wheel set under braking force. The quadratic discretization method is then used to transform this time-history into a braking and bending force time-history of a structural fixed node, and a dynamic response analysis of the seismically isolated bridge under the vehicle＇s braking force is carried out using ANSYS, a universal finite element analysis software. According to the results, seismic isolation design results in a more rational distribution of braking force among piers; the influence of the initial braking velocity on the vehicle braking force is negligible; the location where the first wheel set leaves the bridge is the most unfavorable parking location; a seismic isolation bridge bearing constructed according to typical design methods enters into a yield stage under the braking force, while the shearing force at the bottom of the pier declines as the isolation period is extended; the design requirements can be met when the yield displacement of the seismic isolation bearing is less than 5 mm and the yield strength is greater than the braking force.

关键词： seismically isolated bridge braking force coupling vibration quadratic discrete dynamic analysis

Study on dynamic stiffness of supporting structure and its influence on vibration of rotors

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Chinese Journal of Aeronautics 2022年第11期35卷 252-263页

作者： Yongfeng WANG Yanhong MA Jie HONG School of Energyand Power Engineering Beihang UniversityBeijing 100083China Research Institute of Aero-Engine Beijing 100083China

The dynamic response of the rotor depends on not only itself but also the dynamical characteristics of the structures that support it. In this paper, the coupling vibration characteristics of the rotor and supporting structure are studied using one simple rotor-supports model firstly, and then the dynamic stiffness of the typical supporting structure of an aero-engine is investigated in use of both numerical and experimental methods. While, one simulation strategy is developed to include dynamic stiffness of realistic supports in the dynamical analysis of the rotor system. The simulated and tested results show that the dynamic stiffness of the supporting structure not only depends on the structural parameters but also is related to the frequency of the excitation force. The dynamic stiffness is affected by the damping and inertia effect when the excitation frequency is high and closed to the resonance frequency of the support, which may decrease the dynamic stiffness *** resonance frequencies may be induced and the critical speed could be reduced or *** higher vibration response peak and overload of the bearing may also be caused by the varied dynamic stiffness, which needs to be avoided in the design of the rotor-supports system.

关键词： coupling vibration Critical speed Dynamic stiffness Rotor dynamic Rotor-supports system

Adjacent mode resonance of a hydraulic pipe system consisting of parallel pipes coupled at middle points

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Applied Mathematics and Mechanics(English Edition) 2023年第3期44卷 363-380页

作者： Xin FAN Changan ZHU Xiaoye MAO Hu DING Department of Precision Machinery and Precision Instruments University of Science and Technology of ChinaHefei 230022China State-owned Machinery Factory in Wuhu Wuhu 241007Anhui ProvinceChina Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechanoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China

The coupling vibration of a hydraulic pipe system consisting of two pipes is *** pipes are installed in parallel and fixed at their ends,and are restrained by clips to one bracket at their middle *** pipe subjected to the basement excitation at the left end is named as the active pipe,while the pipe without excitation is called the passive *** clips between the two pipes are the bridge for the vibration *** adjacent natural frequencies will enhance the vibration *** governing equation of the coupled system is deduced by the generalized Hamilton principle,and is discretized to the modal *** modal correction is used during the *** investigation on the natural characters indicates that the adjacent natural frequencies can be adjusted by the stiffness of the two clips and *** harmonic balance method(HBM)is used to study the responses in the adjacent natural frequency *** results show that the vibration energy transmits from the active pipe to the passive pipe swimmingly via the clips together with a flexible bracket,while the locations of them are not node *** adjacent natural frequencies may arouse wide resonance curves with two peaks for both *** stiffness of the clip and bracket can release the vibration *** is suggested that the stiffness of the clip on the passive pipe should be weak and the bracket should be strong *** this way,the vibration energy is reflected by the almost rigid bracket,and is hard to transfer to the passive pipe via a soft *** best choice is to set the clips at the pipe node *** current work gives some suggestions for weakening the coupled vibration during the dynamic design of a coupled hydraulic pipe system.

关键词： hydraulic pipe system coupling vibration adjacent mode coupling parallel pipe conveying fluid harmonic balance method(HBM)

Characteristics of ultrasonic vibration transmission in bonding process

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Journal of Central South University of Technology 2005年第5期12卷 567-571页

作者：李军辉闵四宗韩雷钟掘 School of Mechanical and Electronical Engineering Central South University Changsha 410083 China

The transmitting models of ultrasonic vibration in ultrasonic transducer and capillary were presented according to the propagating mechanism of ultrasonic wave in elastic body. The coupling characteristics of ultrasonic longitudinal-complex transverse vibration system were simulated by Matlab software. The ultrasonic vibration displacement and the velocity of high frequency were measured by using the PSV-400-M2(1.5MHz) laser Doppler vibrometer. The vibration locus shapes driven by the same frequency and different frequencies were tested by using GDS-820S dual channel digital oscilloscope. The microstructures at bonding interface were observed by means of KYKY2800 scanning electron microscope. The results show that ultrasonic vibration displacement or velocity and energy density increase with the decrease of section area in the transmitting process. The vibration locus shapes driven simultaneously by the same frequency and different frequencies are elliptical (or circular) loci and rectangular (or square) loci, respectively. And the characteristics at bonding interface are improved by coupling loci.

关键词： ultrasonic bonding coupling vibration transducer ultrasonic longitudinal-complex transverse system

Dynamic Characteristic of Damaged Ship Structures Considering the Warping Deformations

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Journal of Marine Science and Application 2002年第1期1卷 1-8页

作者： NIE Wu, WEN Bao- hua, CHEN Guo- longCollege of Shipbuilding Engineering, Harbin Engineering University, Harbin 150001 , China College of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China

For some largely damaged ships, the conventional methods are unadaptable to estimate their dynamic characteristics as to ships with symmetrical hull section. Based on dry hull modal analysis of flexure — torsion coupling vibration of unsymmetrical ship structures about longitudinal center line, a transfer matrix method to calculate the dynamic characteristics is presented. Taken both shear effect and warping deformations into account, the point and field transfer matrices are derived, and the influence on dynamic characteristics is computed according to different damaged positions and ranges. As examples, the damaged structures are calculated and some interesting conclusions are obtained.

关键词： damaged ship coupling vibration warping dynamic characteristics