Wheel–rail impact and the dynamic forces at discrete supports of rails in the presence of singular rail surface defects

Zhao, Xin; Li, Zili; Liu, J

doi:10.1177/0954409711413975

Cited by 34 publications

(36 citation statements)

References 23 publications

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“…In the literature, rail modeling by a mesh of solid elements has been implemented in some dynamic FE models of the vehicletrack system [15][16][17][18], but modeling of the fastening system and its sufficiency has not been specially discussed. This work presents a detailed investigation of the fastening modeling of multiple spring-damper groups.…”

Section: Introductionmentioning

confidence: 99%

Influence of the Fastening Modeling on the Vehicle-Track Interaction at Singular Rail Surface Defects

Zhao

Dollevoet

2014

Journal of Computational and Nonlinear Dynamics

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With up to 12 spring-damper groups distributed in the actual area of a rail pad, different fastening models are developed in this paper to include the nonuniform pressure distribution within a fastening system and model the constraints at the rail bottom more realistically for the purpose of high frequency dynamics between vehicle and track. Applied to a 3D transient FE model of the vehicle-track interaction, influence of the fastening modeling on the high frequency dynamic contact forces at singular rail surface defects (SRSDs) is examined. Two defect models, one is relatively large and the other is small, are employed. Such a work is of practical significance because squats, as a kind of SRSD, have become a wide spread problem. Results show that the fastening modeling plays an important role in the high frequency dynamic contact forces at SRSDs. Supports in the middle of the rail bottom, modeled as spring-damper groups located under rail web, are found to be most important. The less the rail bottom is constrained or supported, the more isolated the sleepers and substructure are from the wheel-rail interaction, and the more kinetic energy is kept in the rail after impact at a SRSD. Rolling speed is also varied to take into account its influence. Finally, based on the results of this work, influence of the service states of the fastening system on growth of relatively small SRSDs is discussed.

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Section: Introductionmentioning

confidence: 99%

Influence of the Fastening Modeling on the Vehicle-Track Interaction at Singular Rail Surface Defects

Zhao

Dollevoet

2014

Journal of Computational and Nonlinear Dynamics

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“…This simplification is acceptable because the vibration of the sprung mass has a negligible effect on dynamic properties of the wheel-rail contact problem. This is because the wavelength of vibrations of the sprung mass, in the order of meters, is much longer than the size of contact patch between the wheel and rail [42,43]. This means that for the purpose of high-frequency dynamic investigation in the wheel-rail contact, it is not essential to include the vehicle or bogies with their complex configurations into the testing procedure.…”

Section: High-frequency Vibrationsmentioning

confidence: 99%

“…Field observations have shown that the wheel-rail dynamic forces can be directly transferred from the contact interface to the track components and exacerbate the deterioration rate of the track components [45,46]. Conversely, the presence of defects and imperfections in track components can also contribute to highfrequency vibrations of the wheel-track system [43,47]. The results of vehicle-track dynamic simulations in [48] show that the presence of singular rail surface defects (squat for instance) can significantly increase high-frequency dynamic forces between the wheel and rail.…”

Section: Details Down To Track Componentsmentioning

confidence: 99%

Development of a New Downscale Setup for Wheel-Rail Contact Experiments under Impact Loading Conditions

Naeimi

Petrov

et al. 2017

Exp Tech

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A new downscale test rig is developed for investigating the contact between the wheel and rail under impact-like loading conditions. This paper presents the development process of the setup, including review and synthesis of the potential experimental techniques, followed by scalability, mechanical and operational analysis of the new setup. The new test rig intends to remedy the lack of dynamic similarity between the actual railway and the existing laboratory testing capability, by taking into account the factors that contribute to high-frequency dynamics of the wheel-track system. The paper first reviews the functionalities of the existing test techniques in the literature. Based on this survey, the category of the scaled wheel on the rail track ring is chosen. Afterwards, three potential alternatives are identified under the chosen category and the optimum mechanism is achieved through finite element modelling and analysis of the structures. A downscale test rig, consisting of multiple wheel components running over a horizontal rail track ring, effectively fulfilled the requirements needed for analogical testing of the wheel-rail contact behaviour. The new test rig is a unique experimental setup due to the involvement of high-frequency dynamic vibrations in the wheel-track system and analogy of the incorporated elements and loading to those of the real-life system. This paper further presents the results of some real experiments carried out using the newly-built setup to support substantial ideas behind its development.

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“…The results calculated by the two different meshes will be compared in the later analyses. The other track parameters involved in the model were taken from [8].…”

Section: 1mentioning

confidence: 99%

An Explicit Integration Finite Element Method for Impact Noise Generation at a Squat

Yang

Dollevoet

2015

Notes on Numerical Fluid Mechanics and Multidisciplinary Design

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SummaryThis paper presents a full finite element (FE) interaction model of wheel-track to study the wheel-rail impact noise caused by squat. The wheel, the rail and some other track components are modeled with finite elements in three dimensions, where necessary and appropriate. Realistic contact geometry, including geometric irregularity (squat) in the contact surfaces is considered. The integration is performed in the time domain with an explicit central difference scheme. For convergence, the Courant time step condition is enforced, which, together with the detailed modeling of the structural and continuum of the wheel-track system, effectively guarantees that vibration frequency of 10 kHz or higher is reproduced. By making use of the calculated velocities and pressures on the vibrating surfaces, the boundary element method (BEM) based on Helmholtz equation is adopted to transform the vibration of the track into acoustic signal.

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Wheel–rail impact and the dynamic forces at discrete supports of rails in the presence of singular rail surface defects

Cited by 34 publications

References 23 publications

Influence of the Fastening Modeling on the Vehicle-Track Interaction at Singular Rail Surface Defects

Influence of the Fastening Modeling on the Vehicle-Track Interaction at Singular Rail Surface Defects

Development of a New Downscale Setup for Wheel-Rail Contact Experiments under Impact Loading Conditions

An Explicit Integration Finite Element Method for Impact Noise Generation at a Squat

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