scholarly journals Vertical Random Vibration Analysis of Track-Subgrade Coupled System in High Speed Railway with Pseudoexcitation Method

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Xinwen Yang ◽  
Xiaoshan Liu ◽  
Shunhua Zhou ◽  
Xiaoyun Ma ◽  
Jiangang Shen ◽  
...  
Keyword(s):  
Asphalt Concrete ◽  
High Speed ◽  
Random Vibration ◽  
Coupled System ◽  
Beam Model ◽  
Vehicle Speed ◽  
Coupling Vibration ◽  
Ballastless Track ◽  
Vibration Responses ◽  
Random Irregularity

In order to reduce the ground-borne vibration caused by wheel/rail interaction in the ballastless track of high speed railways, viscoelastic asphalt concrete materials are filled between the track and the subgrade to attenuate wheel/rail force. A high speed train-track-subgrade vertical coupled dynamic model is developed in the frequency domain. In this model, coupling effects between the vehicle and the track and between the track and the subgrade are considered. The full vehicle is represented by some rigid body models of one body, two bogies, and four wheelsets connected to each other with springs and dampers. The track and subgrade system is considered as a multilayer beam model in which layers are connected to each other with springs and damping elements. The vertical receptance of the rail is discussed and the receptance contribution of the wheel/rail interaction is investigated. Combined with the pseudoexcitation method, a solution of the random dynamic response is presented. The random vibration responses and transfer characteristics of the ballastless track and subgrade system are obtained under track random irregularity when a high speed vehicle runs through. The influences of asphalt concrete layer’s stiffness and vehicle speed on track and subgrade coupling vibration are analyzed.

The Calculation of the Supporting Stress of Track Plate in Ballastless High-Speed Rail Structure

2011 ◽  
Vol 97-98 ◽  
pp. 3-9
Author(s):  
Yang Wang ◽  
Quan Mei Gong ◽  
Mei Fang Li
Keyword(s):  
Stress Distribution ◽  
High Speed ◽  
Design Theory ◽  
Moving Load ◽  
Structure Design ◽  
Track Structure ◽  
Beam Model ◽  
High Speed Rail ◽  
Slab Track ◽  
Ballastless Track

The slab track is a new sort of track structure, which has been widely used in high-speed rail and special line for passenger. However, the ballastless track structure design theory is still not perfect and can not meet the requirements of current high-speed rail and passenger line ballastless track. In this paper, composite beam method is used to calculate the deflection of the track plate and in this way the vertical supporting stress distribution of the track plate can be gotten which set a basis for the follow-up study of the dynamic stress distribution in the subgrade. Slab track plate’s bearing stress under moving load is analyzed through Matlab program. By calculation and analysis, it is found that the deflection of track plate and the rail in the double-point-supported finite beam model refers to the rate of spring coefficient of the fastener and the mortar.The supporting stress of the rail plate is inversely proportional to the supporting stress of the rail. The two boundary conditions of that model ,namely, setting the end of the model in the seams of the track plate or not , have little effect on the results. We can use the supporting stress of the track plates on state 1to get the distribution of the supporting stress in the track plate when bogies pass. Also, when the dynamic load magnification factor is 1.2, the track plate supporting stress of CRST I & CRST II-plate non-ballasted structure is around 40kPa.

Nonlinear Vibration and Bifurcation Analysis for Rotor-Seal-Bearing Systems of Centrifugal Compressors

2007 ◽  
Author(s):  
Yuefang Wang ◽  
Yong Li ◽  
Yong Zhang ◽  
Xiaoyan Wang
Keyword(s):  
High Speed ◽  
Labyrinth Seal ◽  
Journal Bearings ◽  
Coupling Vibration ◽  
Oil Film ◽  
Disc Center ◽  
Multiple Parameters ◽  
Jeffcott Rotor ◽  
Vibration Responses ◽  
The One

This paper presents the nonlinear coupling vibration and bifurcation of a high-speed centrifugal compressor with a labyrinth seal and two journal bearings. The rotor system is modeled as a Jeffcott rotor. The Muszynska’s model is used to express the seal force with multiple parameters. For the journal bearings, the model proposed by Zhang is adopted to express the excitation of unsteady oil-film force. The Runge-Kutta method is used to determine the vibration responses at the disc center and the two bearings. With parameters of rotation speed and pressure difference of the seal, bifurcation diagrams are presented to demonstrate the complexity in the rotor motions. Multiple periodic bifurcations are pointed out using two seal pressure differences. The intricate bifurcation behavior shows inherent interactions between forces of oil-film and seal, which reflect much more complicated rotor dynamics than the one with either of the excitations alone.

Analysis of Dynamic Responses of Bridge-Subgrade Transition of High-Speed Railway

2011 ◽  
Vol 90-93 ◽  
pp. 189-196 ◽  
Author(s):  
Chang Wei Yang ◽  
Jian Jing Zhang ◽  
Chuan Bin Zhu
Keyword(s):  
High Speed ◽  
Deflection Angle ◽  
Coupled System ◽  
Dynamic Responses ◽  
Practical Situation ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Track Dynamics ◽  
Coupling Dynamics ◽  
Analysis Models

Referred the vehicle-track coupling dynamics theory [1] and the vertical dynamic analysis models of Bridge-Subgrade transition developed by Zhai [2] ，Wang [3] and others [4]. This article takes account of the interaction between different structural layers in the subgrade system further by using the dynamic ballastless track model and finally establishes a space dynamic numerical model of the vehicle-track-subgrade coupled system. The dynamic response of the coupled system is analyzed when the speed of the train is 350km/h and the transition is filled with graded broken stones mixed with cement of 3%. Results show that the setting forms of Bridge-Subgrade transition have little effect on the dynamic responses, so designers can choose it on account of the practical situation. Due to the location away from abutment about 5m has greater deformation; the stiffness within 5m should be designed alone. Based on the study from vehicle-track dynamics, we suggest that the maximum allowable track deflection angle is 0.9‰ and K30190Mpa within 5m behind the abutment.

scholarly journals Vehicle Ride Comfort Analysis Based on Vehicle-Bridge Coupled Vibration

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yichang Zhang ◽  
Wusheng Li ◽  
Zhe Ji ◽  
Guichun Wang
Keyword(s):  
Rational Design ◽  
Ride Comfort ◽  
Dynamic Balance ◽  
Dynamic Responses ◽  
Ride Quality ◽  
Vehicle Speed ◽  
Coupled Vibration ◽  
Coupling Vibration ◽  
Multiple Vehicles ◽  
Vibration Responses

The study in this paper aims to evaluate the effects of vehicle-bridge coupled vibration on the vehicle ride comfort. The mechanical model of both vehicle and bridge subsystems and the vibration differential equations are established, respectively, based on the principle of dynamic balance and finite element method. The APDL command stream for iterative calculation is compiled on the ANSYS platform. The method to evaluate the vehicle ride comfort is established according to the criteria in ISO2631-1-1997. The vehicle dynamic responses and ride comfort are analyzed considering different pavement levels while multiple vehicles pass through the cable-stayed bridge. The analysis results indicate that the dynamic responses of vehicles decrease with the improvement of pavement roughness, resulting in the vehicle ride comfort to be better; the dynamic responses of vehicles increase with the increment of vehicle speed or the decrement of vehicle gravity, resulting in the vehicle ride comfort to be worse. The present research results can provide an insight into the rational design of bridge structure so as to reduce the vehicle-bridge coupling vibration responses and improve the ride quality of drivers and passengers.

Study on Reasonable Length of Ballasted-CRTS II Ballastless Track Transition Section on High-Speed Railway Bridge

2013 ◽  
Vol 671-674 ◽  
pp. 1301-1305 ◽  
Author(s):  
Yu Liu ◽  
Guo Tang Zhao
Keyword(s):  
High Speed ◽  
Stability Index ◽  
Dynamic Interaction ◽  
Railway Bridge ◽  
The Finite Element Method ◽  
High Speed Railway ◽  
Transition Section ◽  
Ballastless Track ◽  
Rail Deflection ◽  
Random Irregularity

In view of ballasted-CRTSⅡ ballastless track transition section on the bridge of Beijing-Shanghai high-speed railway, the influence of track random irregularity and pier foundation settlement difference on acceleration and stability index of locomotive body are discussed by the finite element method. And then, by using the index of rail deflection gradient to describe the law of dynamic interaction, rail-wheel dynamic response, attenuation distance of locomotive body acceleration and change of sleeper pressure caused by under-rail stiffness difference are analyzed. Finally, the recommended value of reasonable length of transition section is put forwarded.

Random Vibration Properties of High-Speed Railway Vehicle Considering Random Parameters of Track Structure

2013 ◽  
Vol 321-324 ◽  
pp. 62-66
Author(s):  
Bin Li ◽  
Xue Yi Liu
Keyword(s):  
High Speed ◽  
Random Vibration ◽  
Railway Vehicle ◽  
Random Parameters ◽  
High Speed Railway ◽  
Speed Increase ◽  
Vibration Properties ◽  
Track System ◽  
Vibration Responses ◽  
Train Speed

Applied theory of vehicle/track coupled dynamic, random vibration properties of high-speed railway vehicles are researched in random parameters of fastener and ballast stiffness obeyed normal distribution and track irregularity combined the sample of artificial shortwave and the sample of low disturbance irregularity of high-speed railway in German with train speed increase. The results show that dynamic interaction of vehicle/track system and vibration responses of railway vehicle are increased with train speed increase, but the increase of wheel-set acceleration is much more. The parameters of high speed railway track structure (especially fastener and ballast stiffness) had much more impact to random vibration responses of vehicle/track system, so they should be optimized and remained in a narrow range.

scholarly journals Dynamic Responses of Asphalt Concrete Waterproofing Layer in Ballastless Track

2019 ◽  
Vol 9 (3) ◽  
pp. 375 ◽  
Author(s):  
Jie Zhou ◽  
Xianhua Chen ◽  
Qinghong Fu ◽  
Gang Xu ◽  
Degou Cai
Keyword(s):  
Cross Section ◽  
Asphalt Concrete ◽  
Test Section ◽  
High Speed ◽  
Viscoelastic Behavior ◽  
Dynamic Responses ◽  
Track Structure ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Full Cross Section

The application of asphalt concrete waterproofing layer (ACWL) for the subgrade has been a trend in Chinese high-speed railway. The purpose of this research is to discuss the dynamic characteristics of full cross-section ACWL in the ballastless track structure under the train loads. The laboratory tests were conducted to evaluate the performance of the asphalt mixtures for the ACWL and a test section of ACWL was constructed on the high-speed railway in north China. The linear viscoelastic behavior of the asphalt concrete obtained from the test section was characterized by the generalized Maxwell model according to the results of dynamic modulus test. Then a 3D finite element model for the interaction system of vehicle and ballastless track structure was presented and validated by field measured data. The results indicated that the tensile strain at the bottom of the ACWL was at a relatively low level and the vertical dynamic responses of each structural layer are obviously reduced due to the application of ACWL. Therefore, the full cross-section ACWL helps to reduce the vibration of the track structure and maintain the long-term stability of the subgrade.

Dynamic Response of Bridges to Moving Trains: A Study on Effects of Concrete Creep and Temperature Deformation

2012 ◽  
Vol 193-194 ◽  
pp. 1179-1182 ◽  
Author(s):  
Wen Qiu Li ◽  
Yan Zhu ◽  
Xiao Zhen Li
Keyword(s):  
High Speed ◽  
Coupled System ◽  
Dynamic Responses ◽  
Effect Of Temperature ◽  
Temperature Deformation ◽  
Vertical Acceleration ◽  
Dynamic Feature ◽  
Wheel Load ◽  
Coupling Vibration ◽  
Track Irregularities

In this paper, a great deal of research undertaken to study the dynamic responses of a high-speed railway bridge subjected to moving trains. Based on coupling vibration analysis of a rigid frame-continuous bridge, the effect on the kinetic characteristics induced by track irregularities, temperature and creep is discussed. The results show that great changes occur in parameters of trains such as rate of wheel load reduction, the vertical acceleration and the vertical Sperling index when considering the effect of temperature and creep compared with regarding track irregularities only. It is recommended that the combination of track irregularities, temperature and creep is essential to evaluate dynamic feature of train-bridge coupled system for high-speed railways.

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