Effect of unsupported sleepers on rail track dynamic behaviour

Sadeghi, Javad; Zakeri, Jabbar Ali; Kian, Ali Reza Tolou

doi:10.1680/jtran.16.00161

Cited by 20 publications

(13 citation statements)

References 35 publications

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“…The track irregularity evolution in the zone of the dipped weld under the influence of rail pad stiffness and the void depth is studied using the model. A three-dimensional numerical model of track was used in the study [ 35 ] to explore the effects of unsupported sleepers on the dynamic behavior of railway track. The model has taken into account the prestressing forces, variations of the sleeper cross-section along its length, losing or recovering contact between the sleeper and the ballast layer.…”

Section: Exploration Of Void Influence Of Track-side and On-board Measurements Using Mathematical Modellingmentioning

confidence: 99%

Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Sysyn

Przybyłowicz

Nabochenko

et al. 2021

Sensors

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The ballasted track superstructure is characterized by a relative quick deterioration of track geometry due to ballast settlements and the accumulation of sleeper voids. The track zones with the sleeper voids differ from the geometrical irregularities with increased dynamic loading, high vibration, and unfavorable ballast-bed and sleeper contact conditions. This causes the accelerated growth of the inhomogeneous settlements, resulting in maintenance-expensive local instabilities that influence transportation reliability and availability. The recent identification and evaluation of the sleeper support conditions using track-side and on-board monitoring methods can help planning prevention activities to avoid or delay the development of local instabilities such as ballast breakdown, white spots, subgrade defects, etc. The paper presents theoretical and experimental studies that are directed at the development of the methods for sleeper support identification. The distinctive features of the dynamic behavior in the void zone compared to the equivalent geometrical irregularity are identified by numeric simulation using a three-beam dynamic model, taking into account superstructure and rolling stock dynamic interaction. The spectral features in time domain in scalograms and scattergrams are analyzed. Additionally, the theoretical research enabled to determine the similarities and differences of the dynamic interaction from the viewpoint of track-side and on-board measurements. The method of experimental investigation is presented by multipoint track-side measurements of rail-dynamic displacements using high-speed video records and digital imaging correlation (DIC) methods. The method is used to collect the statistical information from different-extent voided zones and the corresponding reference zones without voids. The applied machine learning methods enable the exact recent void identification using the wavelet scattering feature extraction from track-side measurements. A case study of the method application for an on-board measurement shows the moderate results of the recent void identification as well as the potential ways of its improvement.

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Section: Exploration Of Void Influence Of Track-side and On-board Measurements Using Mathematical Modellingmentioning

confidence: 99%

Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Sysyn

Przybyłowicz

Nabochenko

et al. 2021

Sensors

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“…The result of analyses presented the ratios of the railway track vertical displacement to the vehicle axle load for various foundation stiffness. Sadeghi et al [16] investigated the effects of unsupported sleepers on the dynamic behavior of railway track using a numerical three-dimensional model and illustrated the effects of the various conditions on the rail seat load, sleeper bending moment and sleeper-ballast contact force at various train speeds. Dai et al [17] analyzed dynamic responses of high-speed train-track and investigated various effective factors such as the train speed, the number of hanging sleepers and their pattern via calculation scheme in combination with the moving element method.…”

Section: Literature Reviewmentioning

confidence: 99%

Influence of Rail Pad Stiffness and Axle Loads on Dynamic Responses of Train-track Interaction with Unsupported Sleepers

Zakeri¹,

Fattahi²,

Nouri³

et al. 2020

Period. Polytech. Civil Eng.

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Increasing the axle load causes track deterioration and permanent settlement of the ballast layer. In the ballasted railway tracks, due to the inevitability of unequal settlements in the ballast layer, part of the rail due to high flexural rigidity will become suspended, which causes the formation of the track with unsupported and partially supported sleepers. This situation increases rail vertical displacement and reactions on adjacent sleepers. Several models have been presented to study the effect of unsupported sleepers on dynamic responses of train-track interaction. In this paper, by applying mathematical model, unsupported and partially supported sleepers have been modeled and equations of motions for train-track interaction were written by assuming nonlinear behavior of rail and wheel contact. Following by solving the equations via numerical integration in the time domain, the effect of axle load and pad stiffness on rail vertical displacement were investigated. Results of the analysis suggested that through increasing the axle load rail displacement increased by 13 % in the unsupported sleeper and from 5 to 10 % in the partially supported sleeper. Also, by increasing the pad stiffness rail displacement decreased from 2 to 13 % in the unsupported sleeper and from 1 to 6 % in the partially supported sleeper.

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“…Numerous researches have been carried out, focusing on some issues such as analysis, design, and maintenance processes of ballasted railway superstructures as a conventional track type. [1][2][3][4][5][6] In this regard, the dynamic force imposed between the wheel and the rail is one of the main effective factors of the life cycle of railway ballasted track components. 7,8 So, several researches have been conducted on the effects of ballasted track and vehicle parameters on the wheel/rail dynamic force.…”

Section: Introductionmentioning

confidence: 99%

Effect of rail pad stiffness on the wheel/rail force intensity in a railway slab track with short-wave irregularity

Khajehdezfuly

2019

Proceedings of the Institution of Mechanical Engineers, Part F:

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In this paper, a two-dimensional numerical model is developed to investigate the effect of rail pad stiffness on the wheel/rail force in a slab track with harmonic irregularity. The model consists of a vehicle, nonlinear Hertz spring, rail, rail pad, concrete slab, resilient layer, concrete base, and subgrade. The rail is simulated using the Timoshenko beam element for considering the effects of high-frequency excitation produced by short-wave irregularity. The results obtained from the model are compared with those available in the literature and from the field to prove the validity of the model. Through a parametric study, the effect of variations in rail pad stiffness, vehicle speed, and harmonic irregularity on the wheel/rail force is investigated. For the slab track without any irregularity, the wheel/rail force is at maximum when the vehicle speed reaches the critical speed. As the rail pad stiffness increases, the critical speed increases. When the amplitude of irregularity is high, wheel jumping phenomenon may occur. In this situation, as the vehicle speed and rail pad stiffness are increased, the dynamic wheel/rail force is increased. In the low-frequency range, the wheel/rail force increases as the rail pad stiffness increases. In the high-frequency range, the wheel/rail force increases as the rail pad stiffness is decreased.

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Effect of unsupported sleepers on rail track dynamic behaviour

Cited by 20 publications

References 35 publications

Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Influence of Rail Pad Stiffness and Axle Loads on Dynamic Responses of Train-track Interaction with Unsupported Sleepers

Effect of rail pad stiffness on the wheel/rail force intensity in a railway slab track with short-wave irregularity

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