Fully Coupled Three-Dimensional Train-Track-Soil Model for High-Speed Rail

2014 ◽  
Vol 2448 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Hai Huang ◽  
Yin Gao ◽  
Shelley Stoffels
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Train Track ◽  
High Speed Rail ◽  
Soil Model ◽  
Fully Coupled

The Calculation of Train Slipstreams on Platform of Underground High-Speed Rail Station

2013 ◽  
Vol 842 ◽  
pp. 445-448
Author(s):  
Wei Chao Yang ◽  
Chuan He ◽  
Li Min Peng
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Horizontal Distribution ◽  
Wake Flow ◽  
Railway Tunnel ◽  
Long Distance ◽  
Near Wake ◽  
High Speed Rail ◽  
Numerical Work ◽  
Rail Station

This paper describes the results of numerical work to determine the flow structures of the slipstream and wake of a high speed train on platforms of underground rail station using three-dimensional compressible Euler equation. The simulations were carried out on a model of a simplified three-coach train and typical cross-section of Chinese high-speed railway tunnel. A number of issues were observed: change process of slipstreams, longitudinal and horizontal distribution characteristics of train wind. Localized velocity peaks were obtained near the nose of the train and in the near wake region. Maximum and minimum velocity values were also noticed near to the nose rear tip. These structures extended for a long distance behind the train in the far wake flow. The slipstream in platform shows the typical three-dimensional characteristics and the velocity is about 4 m/s at 6 m away from the edge of platform.

scholarly journals Saturated Ground Vibration Analysis Based on a Three-Dimensional Coupled Train-Track-Soil Interaction Model

2019 ◽  
Vol 9 (23) ◽  
pp. 4991 ◽  
Author(s):  
Li ◽  
Su ◽  
Kaewunruen
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Interaction Model ◽  
Ground Vibration ◽  
Field Measurements ◽  
Soil Conditions ◽  
Layered Soils ◽  
Train Track ◽  
Dynamic Interactions ◽  
Vibration Responses

A novel three-dimensional (3D) coupled train-track-soil interaction model is developed based on the multi-body simulation (MBS) principle and finite element modeling (FEM) theory using LS-DYNA. The novel model is capable of determining the highspeed effects of trains on track and foundation. The soils in this model are treated as saturated media. The wheel-rail dynamic interactions under the track irregularity are developed based on the Hertz contact theory. This model was validated by comparing its numerical results with experimental results obtained from field measurements and a good agreement was established. The one-layered saturated soil model is firstly developed to investigate the vibration responses of pore water pressures, effective and total stresses, and displacements of soils under different train speeds and soil moduli. The multi-layered soils with and without piles are then developed to highlight the influences of multi-layered soils and piles on the ground vibration responses. The effects of water on the train-track dynamic interactions are also presented. The original insight from this study provides a new and better understanding into saturated ground vibration responses in high-speed railway systems using slab tracks in practice. This insight will help track engineers to inspect, maintain, and improve soil conditions effectively, resulting in a seamless railway operation.

scholarly journals Moving element analysis of high-speed rail system accounting for hanging sleepers

2018 ◽  
Vol 148 ◽  
pp. 05007 ◽  
Author(s):  
Jian Dai ◽  
Kok Keng Ang ◽  
Dongqi Jiang
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
High Speed Train ◽  
Train Track ◽  
Element Analysis ◽  
High Speed Rail ◽  
Factors Affecting ◽  
Rail System ◽  
Track System ◽  
Ballasted Track

It is very common in the ballasted track system that sleepers are not well supported by the ballast materials due to the uneven settlement of the ballast under repeated train passage. These unsupported track elements are often termed as hanging sleepers and they can lead to undesirable effects due to increased dynamic response of the train-track system, especially when the speed of the train is high. In this paper, we present a computation scheme in conjunction with the moving element method for the analysis of high-speed train-track dynamics accounting for hanging sleepers. The proposed computational scheme will be first verified by comparison with available analytical results. The dynamic response of a high-speed train traveling on a ballasted track considering unsupported sleepers is next investigated. Various factors affecting the response of the high-speed rail system including the speed of the train, the number of hanging sleepers and the pattern of the hanging sleepers will be examined and discussed.

Dynamic analysis of three-dimensional high-speed train-track model using moving element method

2017 ◽  
Vol 21 (6) ◽  
pp. 862-876 ◽  
Author(s):  
Tan Ngoc Than Cao ◽  
JN Reddy ◽  
Kok Keng Ang ◽  
Van Hai Luong ◽  
Minh Thi Tran ◽  
...  
Keyword(s):  
Dynamic Analysis ◽  
High Speed ◽  
Three Dimensional ◽  
High Speed Train ◽  
Train Track ◽  
Element Method

ANALYSIS OF HIGH-SPEED RAIL ACCOUNTING FOR JUMPING WHEEL PHENOMENON

2014 ◽  
Vol 11 (03) ◽  
pp. 1343007 ◽  
Author(s):  
KOK KENG ANG ◽  
JIAN DAI ◽  
MINH THI TRAN ◽  
VAN HAI LUONG
Keyword(s):  
High Speed ◽  
Computational Study ◽  
Dynamic Responses ◽  
Contact Model ◽  
High Speed Train ◽  
Train Track ◽  
Hertz Contact ◽  
High Speed Rail ◽  
Track System ◽  
Hertz Contact Model

In this paper, a computational study using the moving element method (MEM) was carried out to investigate the dynamic response of a high-speed train–track system. Results obtained using Hertz contact model and linearized Hertz contact model are compared and discussed. The dynamic responses of a train travelling across a uniform foundation and a transition region are also investigated. Parametric study is performed to understand the effect of various factors on the occurrence and patterns of the jumping wheel phenomenon such as the variation of foundation stiffness, travelling speed of the train and the severity of railhead roughness.

High-speed brightfield 3-D imaging and 3-D image analysis of thick and overlapped cell clusters in cytological preparations

1994 ◽  
Vol 52 ◽  
pp. 218-219
Author(s):  
Robert W. Mackin
Keyword(s):  
Image Analysis ◽  
High Speed ◽  
Three Dimensional ◽  
Image Data ◽  
Ccd Camera ◽  
Objective Lens ◽  
Array Processor ◽  
Vaginal Smears ◽  
Low Contrast ◽  
Computer Controlled

This paper presents two advances towards the automated three-dimensional (3-D) analysis of thick and heavily-overlapped regions in cytological preparations such as cervical/vaginal smears. First, a high speed 3-D brightfield microscope has been developed, allowing the acquisition of image data at speeds approaching 30 optical slices per second. Second, algorithms have been developed to detect and segment nuclei in spite of the extremely high image variability and low contrast typical of such regions. The analysis of such regions is inherently a 3-D problem that cannot be solved reliably with conventional 2-D imaging and image analysis methods.High-Speed 3-D imaging of the specimen is accomplished by moving the specimen axially relative to the objective lens of a standard microscope (Zeiss) at a speed of 30 steps per second, where the stepsize is adjustable from 0.2 - 5μm. The specimen is mounted on a computer-controlled, piezoelectric microstage (Burleigh PZS-100, 68/μm displacement). At each step, an optical slice is acquired using a CCD camera (SONY XC-11/71 IP, Dalsa CA-D1-0256, and CA-D2-0512 have been used) connected to a 4-node array processor system based on the Intel i860 chip.

Research on Prediction of High-Speed Rail Trains Delay Time

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Jing Shi ◽  
Qiyuan Peng ◽  
Ling Liu
Keyword(s):  
Delay Time ◽  
High Speed ◽  
High Speed Rail

Effects of Three-Dimensional Pressure Gradients on High-Speed Turbulent Boundary Layers

2021 ◽  
Author(s):  
Scott J. Peltier ◽  
Brian E. Rice ◽  
Ethan Johnson ◽  
Venkateswaran Narayanaswamy ◽  
Marvin E. Sellers
Keyword(s):  
Boundary Layers ◽  
High Speed ◽  
Three Dimensional ◽  
Turbulent Boundary Layers ◽  
Pressure Gradients
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