scholarly journals Influence of Vehicle Number on the Dynamic Characteristics of High-Speed Train-CRTS III Slab Track-Subgrade Coupled System

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3662
Author(s):  
Qingyuan Xu ◽  
Hao Sun ◽  
Lexuan Wang ◽  
Lei Xu ◽  
Wei Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Vibration Reduction ◽  
Coupled System ◽  
Dynamic Responses ◽  
High Speed Train ◽  
Slab Track ◽  
Track Dynamics ◽  
Concrete Base ◽  
Bending Stresses ◽  
Negative Bending

In this paper, a high-speed train–CRTS III slab track–subgrade coupled dynamic model is established. With the model, the influence of vehicle number on the dynamic characteristics of a train–CRTS III slab track–subgrade coupled system with smooth and random track irregularity conditions for conventional and vibration-reduction CRTS III slab tracks are theoretically studied and analyzed. Some conclusions are drawn from the results: (1) the largest dynamic responses of the coupled system for all items and cases are no longer changed when the vehicle number exceeds three, and three vehicles are adequate to guarantee the simulation precision to investigate the dynamic responses of the coupled system. (2) The acceleration of the car body has almost no relation with the vehicle number, and only one vehicle is needed to study the vehicle dynamics using the train–CRTS III slab track–subgrade coupled dynamic model. (3) For the conventional CRTS III slab track on a subgrade, the vehicle number has a negligible influence on the accelerations of the rail, slab, and concrete base, the positive and negative bending moments of the rail, the compressive force of the fastener, and the positive bending stress of slab, but it has a large influence on the tension force of the fastener, and the negative bending stresses of the slab and concrete base. Only one vehicle is needed to study track dynamics without considering the tension force of the fastener, the negative bending stresses of the slab and concrete base, otherwise, two or more vehicles are required. (4) For vibration reduction of the CRTS III slab track on a subgrade, the number of vehicles has some influence on the dynamic responses of all track components, and at least two vehicles are required to investigate the track dynamics.

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 A Review of Different Aspects of Applying Asphalt and Bituminous Mixes under a Railway Track

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 169
Author(s):  
Kazem Jadidi ◽  
Morteza Esmaeili ◽  
Mehdi Kalantari ◽  
Mehdi Khalili ◽  
Moses Karakouzian
Keyword(s):  
High Speed ◽  
Review Paper ◽  
Railway Track ◽  
High Speed Train ◽  
Slab Track ◽  
Bituminous Mixtures ◽  
Railway Tracks ◽  
Potential Applications ◽  
Heavy Loads ◽  
Design And Construction

Asphalt is a common material that is used extensively for roadways. Furthermore, bituminous mixes have been used in railways, both as asphalt and as mortar. Different agencies and research institutes have investigated and suggested various applications. These studies indicate the benefits of bituminous material under railways, such as improving a substructure’s stiffness and bearing capacity; enhancing its dynamic characteristics and response, especially under high-speed train loads; waterproofing the subgrade; protecting the top layers against fine contamination. These potential applications can improve the overall track structure performance and lead to minimizing settlement under heavy loads. They can also guarantee an appropriate response under high-speed loads, especially in comparison to a rigid slab track. This review paper documents the literature related to the utilization of asphalt and bituminous mixes in railway tracks. This paper presents a critical review of the research in the application of asphalt and bituminous mixes in railway tracks. Additionally, this paper reviews the design and construction recommendations and procedures for asphalt and bituminous mixes in railway tracks as practiced in different countries. This paper also provides case studies of projects where asphalt and bituminous mixes have been utilized in railway tracks. It is anticipated that this review paper will facilitate (1) the exchange of ideas and innovations in the area of the design and construction of railway tracks and (2) the development of unified standards for the design and construction of railway tracks with asphalt and bituminous mixtures.

scholarly journals Analysis study the used of Tuned Mass Damper (TMD) on an existing train bridge due to high speed train with moving mass load approach

2019 ◽  
Vol 258 ◽  
pp. 05005 ◽  
Author(s):  
Wivia Octarena Nugroho ◽  
Dina Rubiana Widarda ◽  
Oryza Herdha Dwyana
Keyword(s):  
High Speed ◽  
Tuned Mass Damper ◽  
Dynamic Responses ◽  
Mass Ratio ◽  
High Speed Train ◽  
Maximum Deformation ◽  
Mass Load ◽  
Mass Damper ◽  
Existing Bridges ◽  
Comfort Criteria

As the need of the train speed increased, the existing bridges need to be evaluated, especially in dynamic responses, which are deformation and acceleration. In this study, Cisomang Bridge is modeled and analyzed due to the high-speed train SJ X2 in varying speeds, 50 km/h, 100 km/h, 150 km/h, and 200 km/h. The used of tuned mass damper also will be varied on its setting and placing. The tuned mass dampers setting be varied based on the first or second natural frequency and the placing of tuned mass damper be varied based on maximum deformation of the first or second mode. Moreover, the tuned mass damper ratio will be varied 1% and 1.6%. For all speed variations, dynamic responses of structure without TMD still fulfil the Indonesian Government Criterion based on PM 60 - 2012 but do not meet requirement of comfort criteria based on DIN-Fachbericht 101. Furthermore, only for the speed train 50km/h dynamic responses of structure fulfil safety criteria based on Eurocode EN 1990:2002, whereas the other speed variations do not meet that requirement. In the use of TMD 1% mass ratio, the structure fulfils the safety criteria for all speed variations. In the use of TMD 1.6% mass ratio, all the structure fulfils the safety and comfort criteria except 100 km/h speed which only fulfils the safety criteria.

Dynamic Analysis of Bridge-Approach Embankment Transition Segment

2012 ◽  
Vol 238 ◽  
pp. 719-722
Author(s):  
Zhen Xia Li ◽  
Yuan Zhao Chen
Keyword(s):  
Dynamic Analysis ◽  
Coupled System ◽  
Dynamic Responses ◽  
Subgrade Reaction ◽  
Track Dynamics ◽  
Bridge Approach

Dynamic responses of coupled system were analyzed when the speed of train was 350km/h and the transition was filled with graded broken stones mixed 5% cement. Results indicate that setting form of bridge-approach embankment section has little effect on dynamic responses, thus designers can choose it on account of practical circumstances. Based on the study from vehicle-track dynamics, we suggest that the coefficient of subgrade reaction (K30) should be greater than 190MPa within 0-5m zone behind abutment and be greater than 150MPa in other zones.

Effect of Long-Term Bridge Deformations on Safe Operation of High-Speed Railway and Vibration of Vehicle–Bridge Coupled System

2019 ◽  
Vol 19 (09) ◽  
pp. 1950111 ◽  
Author(s):  
Hongye Gou ◽  
Longcheng Yang ◽  
Zhixiang Mo ◽  
Wei Guo ◽  
Xiaoyu Shi ◽  
...  
Keyword(s):  
High Speed ◽  
Measurement Data ◽  
Coupled System ◽  
Bridge Pier ◽  
Railway Track ◽  
Vertical Acceleration ◽  
High Speed Train ◽  
High Speed Trains ◽  
Track Deformation

Operation safety of high-speed trains is dependent on their vibration characteristics, which vary with bridge deformation. This paper studies the influence of bridge pier settlement and girder creep camber, which are two typical types of long-term bridge deformation, on the vibration of high-speed trains. To this end, an analytical approach is presented to link the bridge deformation with railway track deformation; the track deformation is used to analyze the vibration of the CRH2 high-speed train in China. The vibration analysis results are validated using the in-situ measurement data. The present study shows that bridge pier settlement greatly affects the vertical acceleration, derailment coefficient and wheel unloading rate of the high-speed train; incorporating bridge girder camber aggravates the vibration of the train–bridge system. The threshold of bridge pier settlement is suggested to be 11.1[Formula: see text]mm for trains moving at 350[Formula: see text]km/h with regard to the code-specified vibration limit. This study has significant implications for the design and operation of high-speed railways.

scholarly journals Dynamic characteristics of a high-speed train gearbox in the vehicle–track coupled system excited by wheel defects

2019 ◽  
Vol 234 (10) ◽  
pp. 1210-1226 ◽  
Author(s):  
Zhiwei Wang ◽  
Paul Allen ◽  
Guiming Mei ◽  
Zhonghui Yin ◽  
Yao Cheng ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Stress ◽  
Three Dimensional ◽  
Coupled System ◽  
Transmission System ◽  
Dynamic Responses ◽  
Connected Components ◽  
Dynamics Model ◽  
High Speed Trains ◽  
Polygonal Wear

To analyse and simulate the dynamic responses of the gearbox in a vehicle–track system, a three-dimensional vehicle–track coupled dynamics model for high-speed trains has been developed in this study with a comprehensive consideration of the transmission system. Using this dynamics model, the coupling effects between the gearbox housing and its connected components were analysed. Based on the dynamic results, the dynamic stress field of the gearbox housing can be obtained using the finite element methods. The model outputs were successfully validated through comparisons with field test data. Following model validation, the dynamic stress and its distribution throughout the gearbox housing were further investigated under different excitations, including track irregularities, wheel polygonal wear and flatness. The results demonstrate a significant increase in the stress levels of the oil level window aperture and the bottom face of the housing, which coincides with the location of cracks that are formed in the gearbox housing during frequent vehicle operation. While a specific case has been studied here, the proposed dynamics model can be applied to related dynamic assessments, such as vibration or suspension parameter analyses, as well as to stress analyses of any rail vehicle transmission system to guide the maintenance and design.

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