Coupled dynamic analysis of low and medium speed maglev vehicle-bridge interaction using SIMPACK

2020 ◽  
pp. 095440972092567
Author(s):  
Junxiong Hu ◽  
Weihua Ma ◽  
Shihui Luo
Keyword(s):  
Vertical Vibration ◽  
Dynamic Force ◽  
Vehicle Speed ◽  
Coupled Vibration ◽  
Coupled Dynamic Analysis ◽  
Maglev Vehicle ◽  
Vehicle System ◽  
Medium Speed ◽  
Levitation System ◽  
Multi Body

The low- and medium-speed maglev vehicle generally operates on elevated bridges with a levitation gap of only 8--10 mm, which makes it very sensitive to the vehicle--bridge coupled vibration. To conduct the corresponding modeling and simulation with common dynamics tools, an equivalent processing of the levitation system is required. Using the dynamics software SIMPACK, this paper first introduces the methods of building the multi-body vehicle system, levitation control system and the elastic bridge, respectively, in the SIMPACK railway module, levitation control module and SIMBEAM elastomer module, thus providing a modeling idea for the simulation of the active levitation and operation of low- and medium-speed maglev vehicles through multi-span bridges. It then goes on to simulate and analyze the coupled vibration of a 160 km/h low- and medium-speed maglev vehicle passing through 25 m + 25 m double-span continuous bridges. The research results show that the modeling method introduced in this paper can simulate the low- and medium-speed maglev vehicle--bridge coupled vibration phenomenon, which can be affected significantly by the low-order frequency of the elastic bridge, and can also be intensified under the bridge end impact when the vehicle enters and leaves the bridge. As the running speed of the vehicle increases and the dynamic force increases, the vertical vibration amplitudes of the elastic bridge mid-span, the car body as well as the levitation frame approximate a linear fitting with the vehicle speed. The variation amplitudes of the levitation gap and of the electromagnet current approximate a quadratic fitting with the vehicle speed.

VERTICAL VIBRATION CHARACTERISTICS OF A HIGH-TEMPERATURE SUPERCONDUCTING MAGLEV VEHICLE SYSTEM

2013 ◽  
Vol 27 (15) ◽  
pp. 1362022 ◽  
Author(s):  
JING JIANG ◽  
KE CAI LI ◽  
LI FENG ZHAO ◽  
JIA QING MA ◽  
YONG ZHANG ◽  
...  
Keyword(s):  
High Temperature ◽  
Vibration Frequency ◽  
Excitation Frequency ◽  
Vertical Vibration ◽  
External Excitation ◽  
Maglev Vehicle ◽  
Vehicle System ◽  
High Temperature Superconducting Maglev ◽  
External Excitation Frequency ◽  
Maglev Vehicle System

The vertical vibration characteristics of a high-temperature superconducting maglev vehicle system are investigated experimentally. The displacement variations of the maglev vehicle system are measured with different external excitation frequency, in the case of a certain levitation gap. When the external vibration frequency is low, the amplitude variations of the response curve are small. With the increase of the vibration frequency, chaos status can be found. The resonance frequencies with difference levitation gap are also investigated, while the external excitation frequency range is 0–100 Hz. Along with the different levitation gap, resonance frequency is also different. There almost is a linear relationship between the levitation gap and the resonance frequency.

scholarly journals Rigid-flexible coupling modelling and dynamic performance analysis of novel flexible road wheel

2019 ◽  
Vol 234 (1) ◽  
pp. 67-81
Author(s):  
Yaoji Deng ◽  
Youqun Zhao ◽  
Han Xu ◽  
Fen Lin ◽  
Qiuwei Wang
Keyword(s):  
Dynamic Performance ◽  
Coupled Model ◽  
Vertical Vibration ◽  
Outer Ring ◽  
Vehicle Speed ◽  
Tracked Vehicles ◽  
Operation Conditions ◽  
Combined Structure ◽  
Multi Body ◽  
Dynamic Performance Analysis

A novel flexible road wheel with hub-hinge-ring combined structure is introduced to improve the buffer damping performance and lightweight level of tracked vehicles. To balance computational efficiency and precision, an advanced rigid-flexible coupled model of the flexible road wheel is established using a hybrid modelling method combining finite element method and multi-body dynamics. The reliability and accuracy of the established rigid-flexible coupled model are verified by wheel static loading experiment. The modal flexible body of the elastic outer ring is developed by modified Craig-Bampton method and the simulated results are in good agreement with the experimental data. Based on the verified rigid-flexible coupled model, the dynamic characteristics of the flexible road wheel under typical operation conditions were investigated. The simulation results show that when the motion state changes, the elastic outer ring will produce a hysteretic angle with respect to the hub, delaying the transmission of torque. The system parameters have a greater effect on the vertical vibration of the flexible road wheel. The higher the vehicle speed, the more vibration will be caused, and the increase in the load and number of hinge groups will reduce the vibration. The research results provide reference for structure optimization of flexible road wheel and lay a foundation for flexible multi-body dynamic simulation of tracked vehicles with flexible road wheels.

A numerical model to predict three-dimensional interaction dynamic of low-medium-speed maglev vehicle–guideway bridge system

2021 ◽  
pp. 095440972199655
Author(s):  
Fenghua Huang ◽  
Bin Cheng ◽  
Nianguan Teng
Keyword(s):  
Numerical Model ◽  
Dynamic Responses ◽  
Vehicle Speed ◽  
3D Interaction ◽  
Frequency Responses ◽  
Maglev Vehicle ◽  
Coupling System ◽  
Medium Speed ◽  
Vibration Responses ◽  
Bridge System

This paper established a numerical model to investigate the dynamic behavior of LMS (low-medium-speed) maglev vehicle-guideway bridge coupling system. In this model, the vehicle was simulated as a 3D (3-dimensional) multi-rigid body with 45 DOFs (degree of freedoms), and the guideway bridge was built through finite element method. Two-dimensional magnet-guideway relationship was introduced, and the control strategies of active suspension control based on PID controller and passive guidance control were employed to reflect the vehicle-guideway interaction. A solution program was then developed to solve the vehicle-guideway interaction problem. Through case study, the vibration responses achieved from 3D interaction model were compared to those from corresponding 2D (2-dimensional) model. Besides, the effects of pier and guideway irregularity on dynamic responses of vehicle-guideway bridge coupling system were investigated, and the frequency responses of vehicle and guideway were also analyzed. The result shows that ignoring the pier modeling or guideway irregularity would significantly undervalue the vibration responses of maglev vehicle-guideway bridge interaction system. The frequency responses indicate that the vibrations of vehicle-guideway bridge system are significantly related to the geometric dimensions of maglev vehicle, especially the distance between two magnet units. Finally, parametric study was carried out to determine the effects of key parameters (i.e., vehicle speed and natural frequency of guideway) on guideway responses.

scholarly journals Study on the Urban Rail Transit Sleeper Spacing Considering Vehicle System

2019 ◽  
Vol 296 ◽  
pp. 01008
Author(s):  
Yu Zou ◽  
Yongpeng Wen ◽  
Qian Sun
Keyword(s):  
High Speed ◽  
Coupling Model ◽  
Vertical Vibration ◽  
Vibration Response ◽  
Urban Rail Transit ◽  
Vehicle Speed ◽  
Vertical Coupling ◽  
Vehicle System ◽  
Spectrum Density ◽  
The Impact

To design the optimal sleeper spacing of the track and reduce the vertical vibration of the rail, the influence of the sleeper spacing on the rail vibration is analysed in the vehicle-track vertical coupling model. By comparing the effects of vehicle speed and load on the vibration response of rails under different sleeper spacings, the importance of vehicle system is pointed out. According to the power spectrum density of the vertical rail displacement, the optimal sleeper spacing under the specific line is proposed, and verified via the vibration decay rate. The results show that the sleeper spacing directly affects the first-order Pinned-pinned vibration of the rail, and the effects of the speed and the load on the vibration response are different. In the low-speed section, the impact of the sleeper spacing on the vibration response is smaller, and the larger spacing can be appropriately selected to reduce the number of sleeper to save costs. However, in the high-speed section, the impact is larger, and the speed and the load should be comprehensively considered to select the optimal sleeper spacing.

scholarly journals A new approach to assess the influence of road roughness on driver speed behavior based on driving simulator tests

2016 ◽  
Vol 11 (2) ◽  
pp. 144-152 ◽  
Author(s):  
Mariano Pernetti ◽  
Mauro D’Apuzzo Mauro D’Apuzzo ◽  
Francesco Galante
Keyword(s):  
Driving Simulator ◽  
Experimental Studies ◽  
Vertical Vibration ◽  
The Other ◽  
Added Value ◽  
Published Data ◽  
Vehicle Speed ◽  
Safety Level ◽  
The Road ◽  
Road Roughness

Vehicle speed is one of main parameters describing driver behavior and it is of paramount importance as it affects the travel safety level. Speed is, in turn, affected by several factors among which in-vehicle vibration may play a significant role. Most of speed reducing traffic calming countermeasures adopted nowadays rely on vertical vibration level perceived by drivers that is based on the dynamic interaction between the vehicle and the road roughness. On the other hand, this latter has to be carefully monitored and controlled as it is a key parameter in pavement managements systems since it influences riding comfort, pavement damage and Vehicle Operating Costs. There is therefore the need to analyse the trade-off between safety requirements and maintenance issues related to road roughness level. In this connection, experimental studies aimed at evaluating the potential of using road roughness in mitigating drivers’ speed in a controlled environment may provide added value in dealing with this issue. In this paper a new research methodology making use of a dynamic driver simulator operating at the TEST Laboratory in Naples is presented in order to investigate the relationship between the driver speed behavior on one hand, and the road roughness level, road alignment and environment, vehicle characteristics on the other. Following an initial calibration phase, preliminary results seem fairly promising since they comply with the published data derived from scientific literature.

Experimental study on vertical vibration characteristics of medium-low speed maglev vehicle when standing still on steel beams

2021 ◽  
pp. 095440972110324
Author(s):  
Miao Li ◽  
Xiaohao Chen ◽  
Shihui Luo ◽  
Weihua Ma ◽  
Cheng Lei ◽  
...  
Keyword(s):  
Coupled System ◽  
Vertical Vibration ◽  
Vibration Characteristics ◽  
Steel Beams ◽  
Steel Beam ◽  
Air Spring ◽  
Low Speed ◽  
Maglev Vehicle ◽  
Excited Vibration ◽  
Eigen Frequencies

Levitation stability is the very basis for the dynamic operation of Electromagnetic Suspension (EMS) medium-low speed maglev trains (MSMT). However, self-excited vibration tends to occur when the vehicle is standing still above the lightweight lines, which remains a major constraint to the promotion of medium-low speed maglev technology. In order to study the vertical vibration characteristics of the coupled system of MSMT when it is standing still above lightweight lines, levitation tests were carried out on two types of steel beams: steel beam and active girder of the turnout, with a newly developed maglev vehicle using levitation frames with mid-set air spring. Firstly, modal tests were carried out on the steel beam to determine its natural vibration characteristics; secondly, the acceleration signals and the dynamic displacement signals of the air spring obtained at each measurement point were analyzed in detail in both the time and frequency domains, and the vertical ride comfort was assessed by means of the calculated Sperling index. Subsequently, theoretical explanations were given for the occurrence of self-excited vibration of coupled system from the perspective of the vehicle-to-guideway vibration energy input. Results show that the eigen frequencies of the vehicle on the steel beam and the turnout are 9.65 Hz and 2.15 Hz, respectively, the former being close to the natural frequency of the steel beam while the latter being close to the natural frequency of the air spring suspension system, thus causing the self-excited vibration of the coupled system. It is recommended to either avoid the main eigen frequencies of the coupled system or to increase the damping of the corresponding vibration modes to guarantee a reliable coupled system for its long-term performance. These results may provide valuable references for the optimal design of medium-low speed maglev systems.

Analysis on Impact Loading at Rail Welds at High Speed

2008 ◽  
Author(s):  
Guangwen Xiao ◽  
Xinbiao Xiao ◽  
Zefeng Wen ◽  
Xuesong Jin
Keyword(s):  
Impact Loading ◽  
High Speed ◽  
Hertzian Contact ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Explicit Integration ◽  
Normal Forces ◽  
Rail Irregularity ◽  
Multi Body ◽  
The Impact

When a railway vehicle passes through a track with different weld irregularities at high speed, the impact loading of the vehicle coupled with the track is investigated in detail using a coupled vehicle/track model. In this model, a half vehicle is considered and modeled as a multi-body system. In the track model, a Timoshenko beam resting on discrete sleepers is applied to model each rail. Each sleeper is modeled as a rigid body accounting for its vertical, lateral, roll motions. A moving sleeper support model is used to simulate the interaction of the vehicle and the track. The ballast bed is replaced with equivalent masses. The equivalent dampers and springs are used to replace the connections between the parts of the vehicle and track. In calculating the coupled vehicle and track dynamics, Hertzian contact theory and the creep force theory by Shen et al. are, respectively, used to calculate the normal forces and the creep forces between the wheels and the rails. The motion equations of the vehicle-track are solved by means of an explicit integration method. The weld rail irregularity is modeled by setting a local track vertical deviation at a rail weld joint, which is described with a simplified cosine function. In the numerical analysis the effect of the different wavelength, depth, the position of the welded joint in a sleeper span, and vehicle speed is taken into account. The numerical results obtained are greatly useful in the tolerance design of welded rail profile irregularity caused by damage and hand-grinding after rail welding.

scholarly journals Soil-Pile Interaction in the Pile Vertical Vibration Based on Fictitious Soil-Pile Model

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Guodong Deng ◽  
Jiasheng Zhang ◽  
Wenbing Wu ◽  
Xiong Shi ◽  
Fei Meng
Keyword(s):  
Dynamic Response ◽  
Separation Of Variables ◽  
Vertical Vibration ◽  
Dynamic Responses ◽  
Dynamic Force ◽  
Laplace Transform Technique ◽  
Velocity Response ◽  
Pile Interaction ◽  
Pile Model ◽  
Fictitious Soil

By introducing the fictitious soil-pile model, the soil-pile interaction in the pile vertical vibration is investigated. Firstly, assuming the surrounding soil of pile to be viscoelastic material and considering its vertical wave effect, the governing equations of soil-pile system subjected to arbitrary harmonic dynamic force are founded based on the Euler-Bernoulli rod theory. Secondly, the analytical solution of velocity response in frequency domain and its corresponding semianalytical solution of velocity response in time domain are derived by means of Laplace transform technique and separation of variables technique. Based on the obtained solutions, the influence of parameters of pile end soil on the dynamic response is studied in detail for different designing parameters of pile. Lastly, the fictitious soil-pile model and other pile end soil supporting models are compared. It is shown that the dynamic response obtained by the fictitious soil-pile model is among the dynamic responses obtained by other existing models if there are appropriate material parameters and thickness of pile end soil for the fictitious soil-pile model.

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