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• Innovative dynamic model for track buckling failure analysis; • Numerical presentation the dynamic process of track buckling failure; • Combining Finite Element Method and Multibody dynamics to allow track dynamic and structural analysis. Traditional analyses on track buckling failure have primarily focused on the static structural mechanics of railway tracks under thermal stress. However, to better understand the dynamic buckling failure phenomenon, it is essential to consider variable factors within the computational modelling framework. This study addresses this gap by simulating ballasted track buckling failure while incorporating dynamic force inputs and rail stiffness adjustments due to both thermal and longitudinal forces. The rails are modelled as Euler-Bernoulli beams using the Finite Element Method (FEM), and other tack components are represented as equivalent rigid bodies connected by flexible force elements. A friction model at the sleeper-ballast interface is integrated, and rail stiffness—primarily in the lateral direction—is adjusted to reflect the influence of longitudinal forces. This computational modelling of railway tracks enables a comprehensive view of the forces and displacements experienced by the individual track components, offering insights on total track behaviour. By incorporating dynamic forces into the buckling analysis, this FEM-enabled rail components significantly enhance the simulation capability of track buckling in the time domain. Additionally, track model is scalable and configurable, enabling simulations using a wide range of track parameters. The effectiveness of the developed ballasted track model is demonstrated through case studies, where a 30-meter track section under thermal compression and application of dynamic lateral loads exhibits a nonlinear buckling response. [ABSTRACT FROM AUTHOR]

Most railway track dynamics models focus on vertical and lateral directions. Vehicle dynamics have strong implications for track longitudinal dynamics, but railway track longitudinal force models are rarely published. This paper developed a three-dimensional railway track model which considers four structure layers: rails, sleepers, ballast and subballast. The rails are modelled using the Finite Element Method and each node has six Degrees of Freedom (DoFs). Sleepers are modelled as rigid bodies and each also has six DoFs. Ballast and subballast are modelled as blocks and each has three translational DoFs. Frictional behaviour is considered in the longitudinal direction of the fastening models as well as in the longitudinal and lateral directions of the sleeper-ballast force connections. Validations of the model are presented in this paper. Simulations of longitudinal forces are also presented. The results show that the model has the capability of simulating track longitudinal forces and the rail creep phenomenon. [ABSTRACT FROM AUTHOR]

Abstract The dynamic properties of a railway track are important for both the generation of rolling noise and the development of rail corrugation. A conventional track consists of long rails mounted periodically on transverse sleepers and supported in ballast. In order to improve the predictions of the noise and vibration of the track, a model of a discretely supported track is proposed based on the so-called 2.5 dimensional (2.5D) finite element approach, which is used to model an infinite free rail. This is coupled to a finite number of sleepers, by means of an array of springs representing each rail pad, using a receptance coupling method. The sleepers are represented by flexible beams, supported on an elastic foundation. Results are presented in terms of the point mobility and track decay rate and these are compared with the corresponding field measurements for two tracks, one with soft rail pads and one with stiff rail pads. Very good agreement is found between the predictions and the measurement results, especially for the track with soft rail pads. The flexible sleeper model is shown to give improved results compared with a rigid mass model, especially for the track with stiff rail pads. [ABSTRACT FROM AUTHOR]

Abstract: Vibration assessments are required for new railroad lines to determine the effect of vibrations on local communities. Low accuracy assessments can significantly increase future project costs in the form of further detailed assessment or unexpected vibration abatement measures. This paper presents a new, high accuracy, initial assessment prediction tool for high speed lines. A key advantage of the new approach is that it is capable of including the effect of soil conditions in its calculation. This is novel because current scoping models ignore soil conditions, despite such characteristics being the most dominant factor in vibration propagation. The model also has zero run times thus allowing for the rapid assessment of vibration levels across rail networks. First, the development of the new tool is outlined. It is founded upon using a fully validated three dimensional finite element model to generate synthetic vibration records for a wide range of soil types. These records are analysed using a machine learning approach to map relationships between soil conditions, train speed and vibration levels. Its performance is tested through the prediction of two independent international vibration metrics on four European high speed lines and it is found to have high prediction accuracy. A key benefit from this increased prediction accuracy is that it potentially reduces the volume of detailed vibration analyses required for a new high speed train line. This avoids costly in-depth studies in the form of field experiments or large numerical models. Therefore the use of the new tool can result in cost savings. [Copyright &y& Elsevier]