A mixed space-time and wavenumber domain model for predicting ground vibration from railway tracks
A mixed space-time and wavenumber domain model for predicting ground vibration from railway tracks
In this paper, a mixed model for studying ground vibration generated from surface railway tracks is presented. A ballasted track with nonlinear resilient components is modelled in the time domain using the Finite Element method. The ground is modelled as a linear homogeneous half-space in the wavenumber domain for faster computation. The interaction between the track and the ground is incorporated into the track model through a lumped parameter model representing the vertical dynamic stiffness of the ground. The coefficients of the components of the lumped parameter model are obtained by curve fitting of the transfer function of the half-space for a load applied at its origin. The coupled equation of motion for the track/ground system is formulated with excitation from a stationary point load-consisting of static and dynamic partsacting at the centre of the rail. The coupled equation is solved by numerical integration. The calculated interaction forces at the ballast/ground interface from the space-time domain track model are Fourier transformed to the wavenumber domain and used as excitation to the ground model in order to calculate free-field surface vibration of the ground. Results are presented for the vertical dynamic stiffness for the ground, and for the track and ground displacement in the vicinity of the track and in the free-field. A comparative study between the mixed formulation with the lumped parameter model for the ground, and a fully coupled wavenumber domain model is conducted for linear parameters. Using the fully coupled model as a benchmark, it is observed that the inclusion of the lumped parameter ground model in the track model gives good estimation of the transmitted forces, and hence ground vibration, both in the near and far fields. Finally, the effect of nonlinear track components is briefly investigated for different levels of static preload.
96-107
European Community on Computational Methods in Applied Sciences
Koroma, Samuel
37e63ed0-b7ed-46c4-98b3-d0bb9d96fffd
Thompson, David
bca37fd3-d692-4779-b663-5916b01edae5
Hussein, Mohammed
3535c131-1710-4edc-a4a1-8fe67dee3f67
Ntotsios, Evangelos
877c3350-0497-4471-aa97-c101df72e05e
30 March 2017
Koroma, Samuel
37e63ed0-b7ed-46c4-98b3-d0bb9d96fffd
Thompson, David
bca37fd3-d692-4779-b663-5916b01edae5
Hussein, Mohammed
3535c131-1710-4edc-a4a1-8fe67dee3f67
Ntotsios, Evangelos
877c3350-0497-4471-aa97-c101df72e05e
Koroma, Samuel, Thompson, David, Hussein, Mohammed and Ntotsios, Evangelos
(2017)
A mixed space-time and wavenumber domain model for predicting ground vibration from railway tracks.
In COMPDYN 2015: 5th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering.
European Community on Computational Methods in Applied Sciences.
.
(doi:10.7712/120115.3383.1345).
Record type:
Conference or Workshop Item
(Paper)
Abstract
In this paper, a mixed model for studying ground vibration generated from surface railway tracks is presented. A ballasted track with nonlinear resilient components is modelled in the time domain using the Finite Element method. The ground is modelled as a linear homogeneous half-space in the wavenumber domain for faster computation. The interaction between the track and the ground is incorporated into the track model through a lumped parameter model representing the vertical dynamic stiffness of the ground. The coefficients of the components of the lumped parameter model are obtained by curve fitting of the transfer function of the half-space for a load applied at its origin. The coupled equation of motion for the track/ground system is formulated with excitation from a stationary point load-consisting of static and dynamic partsacting at the centre of the rail. The coupled equation is solved by numerical integration. The calculated interaction forces at the ballast/ground interface from the space-time domain track model are Fourier transformed to the wavenumber domain and used as excitation to the ground model in order to calculate free-field surface vibration of the ground. Results are presented for the vertical dynamic stiffness for the ground, and for the track and ground displacement in the vicinity of the track and in the free-field. A comparative study between the mixed formulation with the lumped parameter model for the ground, and a fully coupled wavenumber domain model is conducted for linear parameters. Using the fully coupled model as a benchmark, it is observed that the inclusion of the lumped parameter ground model in the track model gives good estimation of the transmitted forces, and hence ground vibration, both in the near and far fields. Finally, the effect of nonlinear track components is briefly investigated for different levels of static preload.
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e-pub ahead of print date: 2015
Published date: 30 March 2017
Venue - Dates:
COMPDYN 2015: Computational Methods in Structural Dynamics and Earthquake Engineering, Crete, Greece, 2015-01-01
Organisations:
Dynamics Group
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Local EPrints ID: 384384
URI: http://eprints.soton.ac.uk/id/eprint/384384
PURE UUID: 9bab6bb8-8660-4ccf-8510-9bd9ef33df1a
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Date deposited: 16 Dec 2015 13:03
Last modified: 17 Mar 2024 02:44
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Author:
Samuel Koroma
Author:
Mohammed Hussein
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