Wheel/Rail Dynamics Simulation for Optimising Minimum Grade Lengths to High-Speed Railways

2007 ◽  
Author(s):  
Zengjie Liu ◽  
Lan Wang
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
Minimum Length ◽  
Maximum Speed ◽  
Simulation Studies ◽  
High Speed Railway ◽  
Vertical Transition ◽  
Simulation Results ◽  
Curve Radius ◽  
Transition Curves

Based on the principle of no car vibrations interference when trains pass grade section from the end of front vertical curve to the start of latter vertical curve, using railway wheel/rail simulation NUCARS™ software, some dynamics simulation studies for minimum grade lengths on high speed railway lines were made. The dynamics simulation results show that, the minimum tangent lengths between vertical transition curves should be more than 0.43V in meters (V is speed of train, km/h). So the minimum length is 800 meters when the vertical curve radius is 25000 meters, and 900 meters when radius is 30000 meters for the Chinese Dedicated Passenger Railway lines (PDLs) on which maximum speed is 350 km/h and ruling gradient is 12‰.

scholarly journals Dynamic influence of the plane curve radius on vertical- circular overlapping lines of high-speed railway

2021 ◽  
Vol 248 ◽  
pp. 03033
Author(s):  
Xianghui Fan ◽  
Bin Li ◽  
Yongfu Zhang ◽  
Guoqiang Du ◽  
Hua Liu
Keyword(s):  
High Speed ◽  
Plane Curve ◽  
Simulation Software ◽  
The Body ◽  
Dynamics Simulation ◽  
Vertical Acceleration ◽  
High Speed Railway ◽  
Starting Point ◽  
Train Operation ◽  
Curve Radius

In order to reasonably match the horizontal and vertical sections of high-speed railway lines, the vehicle-line spatial coupling model of the vertical-circular overlapping line is established, based on the multi-body dynamics simulation software SIMPACK,. The dynamic indexes of train passing through vertical-circular overlapping lines are calculated when the radii of different plane curves match the corresponding superelevation value. The results show that: on the vertical-circular overlapping line, it is suggested that the maximum plane curve radius is 9000m.The existence of the convex vertical-circular overlapping line worsens the safety of train operation and passenger comfort. The existence of the concave vertical-circular overlapping line is the opposite, but it increases rail wear and the workload of maintenance. The vertical-circular overlapping line has the most obvious influence on the vertical acceleration and the vertical Sperling index of the body. The vertical acceleration of the body is superimposed at the plane gentle circle point and the starting point of the vertical curve, which has a great impact on the stability of the train operation.

Dynamics Equations of Robots Mounted on Moving Bases

1991 ◽  
Author(s):  
R. W. Toogood
Keyword(s):  
Angular Velocity ◽  
Control Systems ◽  
Linear Acceleration ◽  
Computer Code ◽  
Dynamics Simulation ◽  
Simulation Studies ◽  
Flexible Link ◽  
Paper Briefly ◽  
Simulation Results ◽  
Simplification Techniques

Abstract A number of programs have been developed for the automatic symbolic generation of efficient computer code for the dynamic analysis of serial rigid and flexible link manipulators. Code for both the inverse and the direct dynamics computations can be generated. The symbolic generators allow the robot base to be given an arbitrary linear acceleration anchor angular velocity and acceleration. The efficiency of the generated code is an important consideration for simulation studies and/or implementation in control systems. This paper briefly describes the symbolic generation and simplification techniques. The added computational load due to including the base motion is discussed. Some dynamics simulation results are presented for a 3R rigid link manipulator mounted on an oscillating base, which graphically illustrates the effect of the base movement on the dynamics.

scholarly journals Research on Bogie Frame Lateral Instability of High-Speed Railway Vehicle

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Chen Wang ◽  
Shihui Luo ◽  
Ziqiang Xu ◽  
Chang Gao ◽  
Weihua Ma
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
Lateral Acceleration ◽  
Railway Vehicle ◽  
Lateral Instability ◽  
Bogie Frame ◽  
High Speed Railway ◽  
Long Time ◽  
Line Test ◽  
Equivalent Conicity

In order to find out the reason for the bogie frame instability alarm in the high-speed railway vehicle, the influence of wheel tread profile of the unstable vehicle was investigated. By means of wheel-rail contact analysis and dynamics simulation, the effect of tread wear on the bogie frame lateral stability was studied. The result indicates that the concave wear of tread is gradually aggravated with the increase of operation mileage; meanwhile the wheel-rail equivalent conicity also increases. For the rail which has not been grinded for a long time, the wear of gauge corner and wide-worn zone is relatively severe; the matching equivalent conicity is 0.31-0.4 between the worn rail and the concave-worn-tread wheel set. The equivalent conicity between the grinded rail and the concave-worn tread is below 0.25; the equivalent conicities are always below 0.1 between the reprofiled wheel set and various rails. The result of the line test indicates that the lateral acceleration of bogie frame corresponding to the worn wheel-rail can reach 8.5m/s2, and the acceleration after the grinding is reduced below 4.5m/s2. By dynamics simulation, it turns out that the unreasonable wheel-rail matching relationship is the major cause of the bogie frame lateral alarm. With the tread-concave wear being aggravated, the equivalent conicity of wheel-rail matching constantly increases, which leads to the bogie frame lateral instability and then the frame instability alarm.

scholarly journals Study on the Calculation Method of the Diffusion Range of Grouting Slurry for a High-speed Railway Ballastless Track Subgrade

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Changwei Yang ◽  
Jinhao Guo ◽  
Shaowei Wei ◽  
Liang Zhang ◽  
Sifeng Li ◽  
...  
Keyword(s):  
High Speed ◽  
Theoretical Study ◽  
Early Stage ◽  
Soil Mass ◽  
High Speed Railway ◽  
Grouting Pressure ◽  
Diffusion Curve ◽  
Practical Engineering ◽  
Simulation Results ◽  
Diffusion Form

Grouting engineering is the most convenient and quick way to deal with postconstruction settlement. Based on the investigation of the Beijing Shenyang high-speed railway in the early stage, the microdestructive force of grout on the soil mass in the process of grouting with the method of fluid solid coupling theory was analyzed. The numerical simulation results show that, in the grouting process, the greater the grouting pressure, the wider the diffusion range of the slurry and the greater the damage to the microscopic contact force of the slurry to the soil; in addition, when the grouting pressure is below 0.15 MPa, the diffusion form of the slurry in the soil is osmotic grouting; when the pressure is about 0.3 MPa, the diffusion form of the slurry in the soil is compacted grouting; on the basis of the simulation results, a deeper research is carried out, and the calculation formula of the slurry diffusion curve is obtained. It fills in the blank of the theoretical study of the slurry diffusion curve. In this paper, the diffusion formula of grouting slurry can be used in the theoretical study of clay grouting, and it can be used as a reference for practical engineering.

scholarly journals Dynamic Analysis of a High-Speed Railway Train With the Defective Axle Bearing

2020 ◽  
Vol 25 (4) ◽  
pp. 525-531
Author(s):  
Jing Liu ◽  
Shangkun Du
Keyword(s):  
Dynamic Analysis ◽  
High Speed ◽  
Time Dependent ◽  
Force Model ◽  
High Speed Railway ◽  
The Road ◽  
Reasonable Approach ◽  
Simulation Results ◽  
Train System ◽  
Track Irregularities

Axle bearings (AXBs) are critical parts for high-speed railway trains (HSTs). Local faults in the AXBs have great influences on the operational dynamics of HSTs. Although some previous works formulated the local faults in single AXB, the vibrations of the whole train system with the defective AXB cannot be described. To overcome this problem, this study conducts a dynamic model for a HST considering a local fault in one AXB. The previous single AXB model cannot formulate the studied case. The impacts caused by the fault in the AXB is defined as a time-dependent force model considering a half-sine type. The road spectrum excitations from the roadbed and rail are formulated by a track irregularities model. The effects of the train speeds and fault sizes on the HST dynamics are introduced. The simulation results from the proposed and previous works are contrasted to show the model validation. The results show that the faults in the AXB will greatly affect the HST dynamics. It depicts that this study can afford a more reasonable approach for understanding the dynamics of HSTs considering the defective AXBs compared to the reported single AXB model.

scholarly journals Calculation of the minimal length of the high-speed line

2021 ◽  
Vol 31 ◽  
pp. 30-35
Author(s):  
Petr Nachtigall ◽  
Erik Tischer
Keyword(s):  
High Speed ◽  
Minimal Length ◽  
Minimum Length ◽  
Maximum Speed ◽  
The Difference

This paper explores the minimum length of continuous sections of the high-speed line. The minimum length is examined in terms of the maximum speed of high-speed vehicles. Both traditional trainsets consisting of traction units and coaches, and train units were selected for examination. The graphs present the difference in the ability of the different vehicles to reach and use the maximumspeed.

scholarly journals Explicit Dynamics Simulation of High-Speed Railway Bearing Based On ANSYS/LS-DYNA

2019 ◽  
Vol 612 ◽  
pp. 032011
Author(s):  
Yongwu Wang ◽  
Gang Zhang ◽  
Canyang Ma ◽  
Kai Yang ◽  
Zhenqiang Zhang ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
High Speed Railway ◽  
Explicit Dynamics

Railway faults spreading model based on dynamics of complex network

2015 ◽  
Vol 29 (06) ◽  
pp. 1550038 ◽  
Author(s):  
Jin Zhou ◽  
Weixiang Xu ◽  
Xin Guo ◽  
Xin Ma
Keyword(s):  
Dynamic Process ◽  
High Speed ◽  
Transmission Rate ◽  
Sir Model ◽  
Directed Network ◽  
High Speed Railway ◽  
Spreading Model ◽  
Accident Causation ◽  
Simulation Results ◽  
Initial Recovery

In this paper, we propose a railway faults spreading model which improved the SIR model and made it suitable for analyzing the dynamic process of faults spreading. To apply our model into a real network, the accident causation network of "7.23" China Yongwen high-speed railway accident is employed. This network is improved into a directed network, which more clearly reflects the causation relationships among the accident factors and provides help for our studies. Simulation results quantitatively show that the influence of failures can be diminished via choosing the appropriate initial recovery factors, reducing the time of the failure detected, decreasing the transmission rate of faults and increasing the propagating rate of corrected information. The model is useful to simulate the railway faults spreading and quantitatively analyze the influence of failures.

Beamforming with Kerdock Codes in LTE System for High-Speed Railway

2014 ◽  
Vol 989-994 ◽  
pp. 3556-3560
Author(s):  
Zhi Hua Yang ◽  
Lei Jun Wang ◽  
Ze Kai Fang
Keyword(s):  
Bit Error Rate ◽  
Communication System ◽  
System Performance ◽  
High Speed ◽  
High Speed Railway ◽  
Kerdock Codes ◽  
Simulation Results ◽  
Complex Multiplications ◽  
Beamforming Technique ◽  
Ber Performance

Beamforming technique based the reciprocity of LTE communication system for high-speed railway is a practical way to improve the system performance in this paper. Kerdock codes, which facilitate efficient codebook and codeword search, are implemented in the LTE system for high-speed railway as the beamforming precoding codebook. The analysis of complexity and simulation results about the communication system of the beamforming with Kerdock codes (KBF) show that the proposed KBF can eliminate complex multiplications and improve the Bit Error Rate (BER) performance at large SNR compared with the existing beamfoming communication system for high-speed railway.

Dynamics simulation of a high-speed railway car operating in low-temperature environments with stochastic parameters

2019 ◽  
Vol 58 (12) ◽  
pp. 1914-1934 ◽  
Author(s):  
Ren Luo ◽  
Wanxiu Teng ◽  
Xingwen Wu ◽  
Huailong Shi ◽  
Jing Zeng
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Dynamics Simulation ◽  
High Speed Railway ◽  
Stochastic Parameters
Sign in / Sign up

Export Citation Format

Share Document