Inverse Problems using an Evolutionary Algorithm applied to the Identification of Railway Track Properties based on Measured and Computed Train-Track Behavior

Purpose – The purpose of this paper is to report the investigations on the potential of a new evolutionary algorithm based on probabilistic models – the quantum-inspired evolutionary algorithm (QEA) in solving inverse problems. Design/methodology/approach – An improved QEA. Findings – The proposed algorithm is an efficient and robust global optimizer for solving inverse problems. Originality/value – To enhance the convergence speed without compromising the diversity performances of the populations, a new definition of global information sharing is introduced and implemented. To guarantee the balance between exploration and exploitation searches, a different migration strategy and formula, as well as a novel formulation for adaptively updating the rotation angle, are developed.

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Load impact on railway track due to unsupported sleepers

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1243/095440905x8790 ◽

2005 ◽

Vol 219 (2) ◽

pp. 67-77 ◽

Cited By ~ 75

Author(s):

A Lundqvist ◽

T Dahlberg

Keyword(s):

Computer Model ◽

Interaction Force ◽

Railway Track ◽

Train Track ◽

Traffic Loading ◽

Track Geometry ◽

Deterioration Rate ◽

Track Dynamics ◽

Force Increase ◽

Load Impact

Ballasted railway tracks will settle as a result of permanent deformations in the ballast and in the underlying material layers. The settlement is caused by the repeated traffic loading and the severity of the settlement depends on the quality and the behaviour of the ballast, the sub-ballast, and the subgrade. As the behaviour of the material is not exactly the same under all sleepers, and since the loading of the track is irregular, the amount of settlement will differ from one sleeper to another. A result of this is that the sleepers are not always fully supported, and some sleepers may even become completely unsupported (voided). A gap appears between the sleeper and the ballast bed. As soon as the track geometry starts to deteriorate, the variations of the train/track interaction force increase, and this speeds up the track deterioration rate. This paper presents a computer model by which the dynamic train/track interaction can be simulated. The influence of one or several voided sleepers on the train/track interaction force and on the track dynamics is investigated. Track settlement due to hanging sleeper(s) is discussed.

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Short soil–binder columns in railway track reinforcement: three–dimensional numerical studies considering the train–track interaction

Computers and Geotechnics ◽

10.1016/j.compgeo.2018.02.001 ◽

2018 ◽

Vol 98 ◽

pp. 8-16 ◽

Cited By ~ 5

Author(s):

André Francisco ◽

André Paixão ◽

José Nuno Varandas ◽

Eduardo Fortunato

Keyword(s):

Three Dimensional ◽

Railway Track ◽

Train Track ◽

Numerical Studies

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Sensor Selection and Placement for Track Switch Condition Monitoring through Validated Structural Digital Twin Models of Train–Track Interactions

Engineering Proceedings ◽

10.3390/ecsa-8-11297 ◽

2021 ◽

Vol 10 (1) ◽

pp. 49

Author(s):

Nikhil Pillai ◽

Jou-Yi Shih ◽

Clive Roberts

Keyword(s):

Finite Element ◽

Strain Sensor ◽

Vertical Direction ◽

Sensor Selection ◽

Railway Track ◽

Fe Model ◽

Train Track ◽

Switch Condition ◽

Before And After ◽

Twin Models

Railway track switches experience high failure rates, which can be reduced by monitoring their structural health. The results obtained from a validated Finite Element (FE) model for train–track switch interaction have been introduced to support sensor selection and placement. For the FE models with nominal and damaged rail profiles, virtual strain sensor measurements have been obtained after converting the true strains to engineering strains. Comparisons for the strains before and after the introduction of the fault have demonstrated greater amplitude for the strains after fault introduction. The highest difference in strain amplitude is in the vertical direction, followed by the longitudinal and lateral directions.

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Dynamic train-track interactions over railway track stiffness transition zones using baseplate fastening systems

Engineering Failure Analysis ◽

10.1016/j.engfailanal.2020.104866 ◽

2020 ◽

Vol 118 ◽

pp. 104866

Author(s):

Chayut Ngamkhanong ◽

Quek Yan Ming ◽

Ting Li ◽

Sakdirat Kaewunruen

Keyword(s):

Railway Track ◽

Train Track ◽

Transition Zones ◽

Track Stiffness

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Dynamic Behavior in Transition Zones and Long-Term Railway Track Performance

Frontiers in Built Environment ◽

10.3389/fbuil.2021.658909 ◽

2021 ◽

Vol 7 ◽

Author(s):

André Paixão ◽

José Nuno Varandas ◽

Eduardo Fortunato

Keyword(s):

Three Dimensional ◽

Structural Response ◽

Railway Track ◽

Train Track ◽

3D Fem ◽

Transition Zones ◽

Complex Structural ◽

Three Dimensional Finite Element ◽

Long Term Behavior

Transition zones between embankments and bridges or tunnels are examples of critical assets of the railway infrastructure. These locations often exhibit higher degradations rates, mostly due to the development of differential settlements, which amplify the dynamic train-track interaction, thus further accelerating the development of settlements and deteriorating track components and vehicles. Despite the technical and scientific interest in predicting the long-term behavior of transition zones, few studies have been able to develop a robust approach that could accurately simulate this complex structural response. To address this topic, this work presents a three-dimensional finite element (3D FEM) approach to simulate the long-term behavior of railway tracks at transition zones. The approach considers both plastic deformation of the ballast layer using a high-cycle strain accumulation model and the non-linearity of the dynamic vehicle-track interaction that results from the evolution of the deformed states of the track itself. The results shed some light into the behavior of transition zones and evidence the complex long-term response of this structures and its interdependency with the transient response of the train-track interaction. Aspects that are critical when assessing the performance of these systems are analyzed in detail, which might be of relevance for researchers and practitioners in the design, construction, and maintenance processes.

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