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Journal ArticleDOI

Effect of the first two wheelset bending modes on wheel-rail contact behavior

07 Dec 2014-Journal of Zhejiang University Science (Zhejiang University Press)-Vol. 15, Iss: 12, pp 984-1001

AbstractThe objective of this paper is to develop a new wheel–rail contact model, which is suitable for considering the effect of wheelset bending deformation on wheel–rail contact behavior at high speeds. Dummies of the two rigid half wheelsets are introduced to describe the spacial positions of the wheels of the deformed wheelset. In modeling the flexible wheelset, the first two wheelset bending modes are considered. Based on the modal synthesis method, these mode values of the wheelset axle are used to solve the motion equations of the flexible wheelset axle modeled as an Euler–Bernoulli beam. The wheel is assumed to be rigid and always perpendicular to the deformed axle at the wheel center. In the vehicle model, two bogies and one car body are modeled as lumped masses. Spring–damper elements are adopted to model the primary and secondary suspension systems. The ballasted track is modeled as a triple-layer discrete elastic supported model. Two high-speed vehicle–track models, one considering rigid wheelset models and the other considering flexible wheelset models, are used to analyze the differences of the numerical results of the two models in both frequency and time domains. In the simulation, a random high-speed railway track irregularity is used as wheel–rail excitations. Wheel–rail forces are calculated and analyzed in the time and frequency domains. The results clarify that this new contact model can characterize very well the influence of the first two bending modes of the wheelset on contact behavior.

Topics: Axle (54%), Hunting oscillation (53%)

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Citations
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Journal ArticleDOI
Abstract: This paper discusses some key problems faced in high-speed train operation. These problems include: wheel tread concave wear causing the lateral oscillation of the train in operation, wheel roundness higher-order polygonal wear leading to fierce vertical vibration of wheel/rail and abnormal vibration noise of the coach interior of the train thus causing loosening and cracking of the train bogie parts, short pitch rail corrugation generation on the part of the track, fracture of cushion layer and road base fracture of the track, and increased noise inside and outside the train. At present, the mechanism of the occurrence and development of these phenomena is still not fully understood. This paper briefly reviews the related research on these problems in China and abroad, including many important recent papers and the articles published in this special issue. They make outstanding contributions to solving these problems, and include important work on train-track coupling large system theory, the relationship theory and technique of wheel/rail, and the vibration-noise reduction technology of the train.

53 citations


Journal ArticleDOI
TL;DR: A three-dimensional dynamic model of a high-speed train coupled with a ballast track for dynamic derailment analysis is presented, in which the commonly used derailment safety assessment criteria around the world are embedded in the simulation model.
Abstract: The running safety of high-speed trains has become a major concern of the current railway research with the rapid development of high-speed railways around the world. The basic safety requirement is to prevent the derailment. The root causes of the dynamic derailment of high-speed trains operating in severe environments are not easy to identify using the field tests or laboratory experiments. Numerical simulation using an advanced train-track interaction model is a highly efficient and low-cost approach to investigate the dynamic derailment behavior and mechanism of high-speed trains. This paper presents a three-dimensional dynamic model of a high-speed train coupled with a ballast track for dynamic derailment analysis. The model considers a train composed of multiple vehicles and the nonlinear inter-vehicle connections. The ballast track model consists of rails, fastenings, sleepers, ballasts, and roadbed, which are modeled by Euler beams, nonlinear spring-damper elements, equivalent ballast bodies, and continuous viscoelastic elements, in which the modal superposition method was used to reduce the order of the partial differential equations of Euler beams. The commonly used derailment safety assessment criteria around the world are embedded in the simulation model. The train-track model was then used to investigate the dynamic derailment responses of a high-speed train passing over a buckled track, in which the derailment mechanism and train running posture during the dynamic derailment process were analyzed in detail. The effects of train and track modelling on dynamic derailment analysis were also discussed. The numerical results indicate that the train and track modelling options have a significant effect on the dynamic derailment analysis. The inter-vehicle impacts and the track flexibility and nonlinearity should be considered in the dynamic derailment simulations.

43 citations


Journal ArticleDOI
TL;DR: The characteristics, effects, causes, and solutions of wheel polygonisation in metro vehicles, locomotives, and high-speed trains in China are summarized and guidance is provided on further understanding the formation mechanisms, monitoring technology, and maintenance criterion of wheel Polygonisation.
Abstract: Polygonisation is a common nonuniform wear phenomenon occurring in railway vehicle wheels and has a severe impact on the vehicle–track system, ride comfort, and lineside residents. This paper first summarizes periodic defects of the wheels, including wheel polygonisation and wheel corrugation, occurring in railways worldwide. Thereafter, the effects of wheel polygonisation on the wheel–rail interaction, noise and vibration, and fatigue failure of the vehicle and track components are reviewed. Based on the different causes, the formation mechanisms of periodic wheel defects are classified into three categories: (1) initial defects of wheels, (2) natural vibration of the vehicle–track system, and (3) thermoelastic instability. In addition, the simulation methods of wheel polygonisation evolution and countermeasures to mitigate wheel polygonisation are presented. Emphasis is given to the characteristics, effects, causes, and solutions of wheel polygonisation in metro vehicles, locomotives, and high-speed trains in China. Finally, the guidance is provided on further understanding the formation mechanisms, monitoring technology, and maintenance criterion of wheel polygonisation.

24 citations


Journal ArticleDOI
Abstract: Cement asphalt mortar (CAM) softening is a common phenomenon that results from aging and rain soaking when a high-speed railway is in service. CAM softening seriously affects vehicle operation safety and track dynamics. In this paper, a 3D coupling dynamic model of a vehicle and a China railway track system I (CRTS-I) slab track is developed. By using the proposed model, the wheel-rail contact forces, derailment coefficient, wheelset loading reduction ratio, and the track displacements are calculated to study the influences of CAM softening on the dynamic characteristics of a vehicle-track system. A track-subgrade finite difference model is developed to study the effect of CAM softening on track damage. The results show that track interface shear failure develops when the CAM softening coefficients reach 10–100. The CAM softening coefficient should not be less than 1000, otherwise a high-speed running vehicle may risk derailment.

20 citations


Cites background from "Effect of the first two wheelset be..."

  • ...Much research work on vehicletrack coupling dynamics and track-subgrade dynamics was carried out (Chen et al., 2014; Ling et al., 2014; Zhong et al., 2014)....

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Journal ArticleDOI
Abstract: A rotating flexible wheelset model is developed and integrated into a vehicle/track dynamic model. Flexible wheelset modes with natural frequencies less than 1000 Hz are considered in the wheelset modelling. An innovation of the paper is that wheel/rail rolling contact calculation considers the effect of the wheelset flexibility and the rotating effect. By introducing two half dummy rigid wheelsets the rolling contact between the flexible wheelset and the two rails can be transformed to that between a rigid wheelset and the rails. As an extension application, the wheel OOR (Out-Of-Round) wears with the 11th, 15th, and 17th orders are used to the vehicle system dynamic model with rigid, flexible and rotating-flexible wheelset model. The results of the three models are compared to study the influence of wheelset flexibility and rotation. The ‘online searching contact method’ developed in this paper is compared with the traditional contact method with considering the rotating flexible wheelset. And then a me...

15 citations


Cites result from "Effect of the first two wheelset be..."

  • ...From Figure 4(b), it indicates that the wheel/rail lateral forces are more sensitive to the influence of the wheelset flexibility, which is in agreement with the conclusions in [19]....

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References
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Journal ArticleDOI
Abstract: (1983). A Comparison of Alternative Creep Force Models for Rail Vehicle Dynamic Analysis. Vehicle System Dynamics: Vol. 12, No. 1-3, pp. 79-83.

408 citations


"Effect of the first two wheelset be..." refers methods in this paper

  • ...The normal wheel-rail contact forces are calculated by the Hertzian nonlinear contact spring model, and the tangent contact forces and spin moments are calculated by means of the model by Shen et al. (1983)....

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Book
01 Jan 1981
TL;DR: This book discusses filter design techniques, components Selection for LC and Active Filters, and how to select the Response Characteristic.
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354 citations


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311 citations


Journal ArticleDOI
Abstract: The C163 Expert Committee of the European Rail Research Institute (ERRI) concerned with Railway Noise, has been developing theoretical models for the generation of wheel/rail rolling noise. These models have been brought together into a software package, called TWINS ("Track-Wheel Interaction Noise Software"). This is intended as a tool with which different designs of wheel and track can be assessed in terms of their noise generation. This paper begins by describing briefly the various theoretical models incorporated, the assumptions made within these models and their limitations. On the basis of the input and output parameters, a methodology is derived for the validation of the model by using full scale running tests. Two sets of experiments have been performed for a range of conditions in which the input parameters (the surface roughnesses of wheel and rail) were measured as fully as possible. As well as the sound pressure during train pass-by, a number of intermediate parameters were also monitored to allow validation of parts of the model.

221 citations


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Abstract: A new method is presented for the analysis of complex dynamic systems which is based on partitioning the system degrees of freedom into a “global” set and a “local” set. The global equations of motion are formulated and solved in a standard deterministic manner, although due account is taken of the presence of the local degrees of freedom via an approach which is analogous to fuzzy structure theory. The local equations of motion are formulated and solved by using statistical energy analysis (SEA) with due account being taken of power input from the global degrees of freedom. The method can be considered to encompass a number of existing analysis techniques and to form a flexible framework within which a number of detailed modeling strategies can be devised. A simple rod system provides an initial application, and it is shown that the method yields very good results from low to high frequency excitation.

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