The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Roger Lewis - One of the best experts on this subject based on the ideXlab platform.
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the development of a high pressure torsion test methodology for simulating wheel rail contacts
Tribology International, 2021Co-Authors: M Evans, L E Buckleyjohnstone, Alexander Meierhofer, Klaus Six, W A Skipper, Roger LewisAbstract:Abstract Simulating the wheel/rail contact of a train is traditionally conducted using small-scale twin-disc testing. Here an emerging alternative method, the “high pressure torsion” (HPT) test is introduced. This has advantages over twin-disc testing as only one cycle is used and it is easier to control third body layers during testing. Shear stress data generated is useful on its own, but can also be used to parameterise analytical prediction tools such as the extended Creep Force model (ECF), which produces Creep-Force curves from HPT data. This can then be validated against field data to develop a full-scale predictive capability. A detailed account of the HPT methodology development and the procedures for running a typical test are presented along with case studies that illustrate the typical output of HPT testing.
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full scale testing of low adhesion effects with small amounts of water in the wheel rail interface
Tribology International, 2020Co-Authors: L E Buckleyjohnstone, Petr Voltr, Gerald Trummer, Roger LewisAbstract:Abstract Low adhesion in the wheel/rail contact can be caused by small amounts of water combining with iron oxides. This happens in light rain or at dew point. In small-scale tests, ultra-low adhesion (≤0.05) has not been maintained. The aim here was to see if the mechanism could be realized at a larger scale. Sustained ultra-low adhesion was achieved when water was applied constantly to the wheel/rail contact at a rate of 25μL/s. In these conditions wear debris and oxide was clearly visible in the contact band. Creep Force data has been generated that can now be used to inform wheel/rail contact models and multi-body dynamics simulations of train behaviour with a view to developing mitigation.
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wheel rail Creep Force model for wayside application of top of rail products incorporating carry on and consumption effects
The IAVSD International Symposium on Dynamics of Vehicles on Roads and Tracks, 2019Co-Authors: Zing Siang Lee, Gerald Trummer, Klaus Six, Roger LewisAbstract:With the current lack of a wheel/rail Creep Force model that simulates the performance of a top-of-rail (TOR) product as a third body layer, this study aims to develop a model for a friction modifier. Pick-up, carry-on and consumption behaviours of the TOR-friction modifier product were thoroughly studied using a full-scale rig (FSR) and a twin disc machine. Results show that the amount of application affects the pick-up, carry-on and consumption behaviours in a FSR setting. In the twin disc setting, the normal pressure affects the consumption behaviour. The experimental data provided the basis for development of a model that allows predictions of the friction behaviour for wayside application of top-of-rail products as a function of distance to the application site and the number of wheel passes.
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wheel rail Creep Force model for predicting water induced low adhesion phenomena
Tribology International, 2017Co-Authors: Gerald Trummer, Petr Voltr, L E Buckleyjohnstone, Roger Lewis, Alexander Meierhofer, Klaus SixAbstract:A computationally efficient engineering model to predict adhesion in rolling contact in the presence of water is presented which may be implemented in multibody dynamics software or in braking models to study train performance and braking strategies. This model has been developed in a project funded by the Rail Safety and Standards Board (RSSB) and Network Rail. It is referred to as the water-induced low adhesion Creep Force (WILAC) model. The model covers a wide range of conditions from dry over damp to wet. Special emphasis is put on little amounts of water which can cause low adhesion without any oil or grease. Such conditions may be encountered in humid weather or at the onset of rain. The model is parameterised based on experimental results from a tram wheel test rig. Adhesion values as low as 0.06 are observed at high Creep with only wear debris and little water present in the contact. The model results also agree with experimental data from locomotive tests in dry and wet conditions.
Klaus Six - One of the best experts on this subject based on the ideXlab platform.
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the development of a high pressure torsion test methodology for simulating wheel rail contacts
Tribology International, 2021Co-Authors: M Evans, L E Buckleyjohnstone, Alexander Meierhofer, Klaus Six, W A Skipper, Roger LewisAbstract:Abstract Simulating the wheel/rail contact of a train is traditionally conducted using small-scale twin-disc testing. Here an emerging alternative method, the “high pressure torsion” (HPT) test is introduced. This has advantages over twin-disc testing as only one cycle is used and it is easier to control third body layers during testing. Shear stress data generated is useful on its own, but can also be used to parameterise analytical prediction tools such as the extended Creep Force model (ECF), which produces Creep-Force curves from HPT data. This can then be validated against field data to develop a full-scale predictive capability. A detailed account of the HPT methodology development and the procedures for running a typical test are presented along with case studies that illustrate the typical output of HPT testing.
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The development of a high pressure torsion test methodology for simulating wheel/rail contacts
Tribology International, 2021Co-Authors: M Evans, Alexander Meierhofer, Klaus Six, W A Skipper, L.e. Buckley-johnstone, Roger LewisAbstract:Abstract Simulating the wheel/rail contact of a train is traditionally conducted using small-scale twin-disc testing. Here an emerging alternative method, the “high pressure torsion” (HPT) test is introduced. This has advantages over twin-disc testing as only one cycle is used and it is easier to control third body layers during testing. Shear stress data generated is useful on its own, but can also be used to parameterise analytical prediction tools such as the extended Creep Force model (ECF), which produces Creep-Force curves from HPT data. This can then be validated against field data to develop a full-scale predictive capability. A detailed account of the HPT methodology development and the procedures for running a typical test are presented along with case studies that illustrate the typical output of HPT testing.
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Wheel/Rail Creep Force Model for Wayside Application of Top-of-Rail Products Incorporating Carry-On and Consumption Effects
Lecture Notes in Mechanical Engineering, 2020Co-Authors: Zing Siang Lee, Gerald Trummer, Klaus Six, Roger LewisAbstract:With the current lack of a wheel/rail Creep Force model that simulates the performance of a top-of-rail (TOR) product as a third body layer, this study aims to develop a model for a friction modifier. Pick-up, carry-on and consumption behaviours of the TOR-friction modifier product were thoroughly studied using a full-scale rig (FSR) and a twin disc machine. Results show that the amount of application affects the pick-up, carry-on and consumption behaviours in a FSR setting. In the twin disc setting, the normal pressure affects the consumption behaviour. The experimental data provided the basis for development of a model that allows predictions of the friction behaviour for wayside application of top-of-rail products as a function of distance to the application site and the number of wheel passes.
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wheel rail Creep Force model for wayside application of top of rail products incorporating carry on and consumption effects
The IAVSD International Symposium on Dynamics of Vehicles on Roads and Tracks, 2019Co-Authors: Zing Siang Lee, Gerald Trummer, Klaus Six, Roger LewisAbstract:With the current lack of a wheel/rail Creep Force model that simulates the performance of a top-of-rail (TOR) product as a third body layer, this study aims to develop a model for a friction modifier. Pick-up, carry-on and consumption behaviours of the TOR-friction modifier product were thoroughly studied using a full-scale rig (FSR) and a twin disc machine. Results show that the amount of application affects the pick-up, carry-on and consumption behaviours in a FSR setting. In the twin disc setting, the normal pressure affects the consumption behaviour. The experimental data provided the basis for development of a model that allows predictions of the friction behaviour for wayside application of top-of-rail products as a function of distance to the application site and the number of wheel passes.
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wheel rail Creep Force model for predicting water induced low adhesion phenomena
Tribology International, 2017Co-Authors: Gerald Trummer, Petr Voltr, L E Buckleyjohnstone, Roger Lewis, Alexander Meierhofer, Klaus SixAbstract:A computationally efficient engineering model to predict adhesion in rolling contact in the presence of water is presented which may be implemented in multibody dynamics software or in braking models to study train performance and braking strategies. This model has been developed in a project funded by the Rail Safety and Standards Board (RSSB) and Network Rail. It is referred to as the water-induced low adhesion Creep Force (WILAC) model. The model covers a wide range of conditions from dry over damp to wet. Special emphasis is put on little amounts of water which can cause low adhesion without any oil or grease. Such conditions may be encountered in humid weather or at the onset of rain. The model is parameterised based on experimental results from a tram wheel test rig. Adhesion values as low as 0.06 are observed at high Creep with only wear debris and little water present in the contact. The model results also agree with experimental data from locomotive tests in dry and wet conditions.
L E Buckleyjohnstone - One of the best experts on this subject based on the ideXlab platform.
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the development of a high pressure torsion test methodology for simulating wheel rail contacts
Tribology International, 2021Co-Authors: M Evans, L E Buckleyjohnstone, Alexander Meierhofer, Klaus Six, W A Skipper, Roger LewisAbstract:Abstract Simulating the wheel/rail contact of a train is traditionally conducted using small-scale twin-disc testing. Here an emerging alternative method, the “high pressure torsion” (HPT) test is introduced. This has advantages over twin-disc testing as only one cycle is used and it is easier to control third body layers during testing. Shear stress data generated is useful on its own, but can also be used to parameterise analytical prediction tools such as the extended Creep Force model (ECF), which produces Creep-Force curves from HPT data. This can then be validated against field data to develop a full-scale predictive capability. A detailed account of the HPT methodology development and the procedures for running a typical test are presented along with case studies that illustrate the typical output of HPT testing.
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full scale testing of low adhesion effects with small amounts of water in the wheel rail interface
Tribology International, 2020Co-Authors: L E Buckleyjohnstone, Petr Voltr, Gerald Trummer, Roger LewisAbstract:Abstract Low adhesion in the wheel/rail contact can be caused by small amounts of water combining with iron oxides. This happens in light rain or at dew point. In small-scale tests, ultra-low adhesion (≤0.05) has not been maintained. The aim here was to see if the mechanism could be realized at a larger scale. Sustained ultra-low adhesion was achieved when water was applied constantly to the wheel/rail contact at a rate of 25μL/s. In these conditions wear debris and oxide was clearly visible in the contact band. Creep Force data has been generated that can now be used to inform wheel/rail contact models and multi-body dynamics simulations of train behaviour with a view to developing mitigation.
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wheel rail Creep Force model for predicting water induced low adhesion phenomena
Tribology International, 2017Co-Authors: Gerald Trummer, Petr Voltr, L E Buckleyjohnstone, Roger Lewis, Alexander Meierhofer, Klaus SixAbstract:A computationally efficient engineering model to predict adhesion in rolling contact in the presence of water is presented which may be implemented in multibody dynamics software or in braking models to study train performance and braking strategies. This model has been developed in a project funded by the Rail Safety and Standards Board (RSSB) and Network Rail. It is referred to as the water-induced low adhesion Creep Force (WILAC) model. The model covers a wide range of conditions from dry over damp to wet. Special emphasis is put on little amounts of water which can cause low adhesion without any oil or grease. Such conditions may be encountered in humid weather or at the onset of rain. The model is parameterised based on experimental results from a tram wheel test rig. Adhesion values as low as 0.06 are observed at high Creep with only wear debris and little water present in the contact. The model results also agree with experimental data from locomotive tests in dry and wet conditions.
Petr Voltr - One of the best experts on this subject based on the ideXlab platform.
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full scale testing of low adhesion effects with small amounts of water in the wheel rail interface
Tribology International, 2020Co-Authors: L E Buckleyjohnstone, Petr Voltr, Gerald Trummer, Roger LewisAbstract:Abstract Low adhesion in the wheel/rail contact can be caused by small amounts of water combining with iron oxides. This happens in light rain or at dew point. In small-scale tests, ultra-low adhesion (≤0.05) has not been maintained. The aim here was to see if the mechanism could be realized at a larger scale. Sustained ultra-low adhesion was achieved when water was applied constantly to the wheel/rail contact at a rate of 25μL/s. In these conditions wear debris and oxide was clearly visible in the contact band. Creep Force data has been generated that can now be used to inform wheel/rail contact models and multi-body dynamics simulations of train behaviour with a view to developing mitigation.
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Particle swarm optimization based parametrization of adhesion and Creep Force models for simulation and modelling of railway vehicle systems with traction
Simulation Modelling Practice and Theory, 2020Co-Authors: Altan Onat, Petr VoltrAbstract:Abstract Adhesion and Creep Force models play an important role in the realistic simulation of railway vehicle systems. These models are mainly based on experiments and they are determined heuristically. In previous studies, no metric is defined to demonstrate the level of agreement between these models and measurements. This study aims to provide such metric, and particle swarm optimization based parametrization of adhesion and Creep Force models is proposed for simulation of railway vehicle systems based on the measurements. Root mean squared error is considered as a metric for the level of agreement between models and measurements. In order to compare two approaches and reveal the superiority of optimal parametrization in simulations with respect to the heuristic approach, measurements taken from a tram wheel test stand, which simulates the traction system of some trams produced in Czechia, are considered. A mathematical model of the traction system of the test stand is obtained for simulation, and two approaches are compared based on the root mean squared error between these simulations and measurements. Several contact conditions are considered during experiments. This study demonstrates the necessity of optimal parametrization of adhesion and Creep Force models for realistic simulation of railway vehicle systems. Furthermore, particle swarm optimization method is introduced as an automation tool for modelling adhesion between wheel and rail when investigation of a large number of measurements are required for design, analysis and simulation.
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wheel rail Creep Force model for predicting water induced low adhesion phenomena
Tribology International, 2017Co-Authors: Gerald Trummer, Petr Voltr, L E Buckleyjohnstone, Roger Lewis, Alexander Meierhofer, Klaus SixAbstract:A computationally efficient engineering model to predict adhesion in rolling contact in the presence of water is presented which may be implemented in multibody dynamics software or in braking models to study train performance and braking strategies. This model has been developed in a project funded by the Rail Safety and Standards Board (RSSB) and Network Rail. It is referred to as the water-induced low adhesion Creep Force (WILAC) model. The model covers a wide range of conditions from dry over damp to wet. Special emphasis is put on little amounts of water which can cause low adhesion without any oil or grease. Such conditions may be encountered in humid weather or at the onset of rain. The model is parameterised based on experimental results from a tram wheel test rig. Adhesion values as low as 0.06 are observed at high Creep with only wear debris and little water present in the contact. The model results also agree with experimental data from locomotive tests in dry and wet conditions.
Gerald Trummer - One of the best experts on this subject based on the ideXlab platform.
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Wheel/Rail Creep Force Model for Wayside Application of Top-of-Rail Products Incorporating Carry-On and Consumption Effects
Lecture Notes in Mechanical Engineering, 2020Co-Authors: Zing Siang Lee, Gerald Trummer, Klaus Six, Roger LewisAbstract:With the current lack of a wheel/rail Creep Force model that simulates the performance of a top-of-rail (TOR) product as a third body layer, this study aims to develop a model for a friction modifier. Pick-up, carry-on and consumption behaviours of the TOR-friction modifier product were thoroughly studied using a full-scale rig (FSR) and a twin disc machine. Results show that the amount of application affects the pick-up, carry-on and consumption behaviours in a FSR setting. In the twin disc setting, the normal pressure affects the consumption behaviour. The experimental data provided the basis for development of a model that allows predictions of the friction behaviour for wayside application of top-of-rail products as a function of distance to the application site and the number of wheel passes.
-
full scale testing of low adhesion effects with small amounts of water in the wheel rail interface
Tribology International, 2020Co-Authors: L E Buckleyjohnstone, Petr Voltr, Gerald Trummer, Roger LewisAbstract:Abstract Low adhesion in the wheel/rail contact can be caused by small amounts of water combining with iron oxides. This happens in light rain or at dew point. In small-scale tests, ultra-low adhesion (≤0.05) has not been maintained. The aim here was to see if the mechanism could be realized at a larger scale. Sustained ultra-low adhesion was achieved when water was applied constantly to the wheel/rail contact at a rate of 25μL/s. In these conditions wear debris and oxide was clearly visible in the contact band. Creep Force data has been generated that can now be used to inform wheel/rail contact models and multi-body dynamics simulations of train behaviour with a view to developing mitigation.
-
wheel rail Creep Force model for wayside application of top of rail products incorporating carry on and consumption effects
The IAVSD International Symposium on Dynamics of Vehicles on Roads and Tracks, 2019Co-Authors: Zing Siang Lee, Gerald Trummer, Klaus Six, Roger LewisAbstract:With the current lack of a wheel/rail Creep Force model that simulates the performance of a top-of-rail (TOR) product as a third body layer, this study aims to develop a model for a friction modifier. Pick-up, carry-on and consumption behaviours of the TOR-friction modifier product were thoroughly studied using a full-scale rig (FSR) and a twin disc machine. Results show that the amount of application affects the pick-up, carry-on and consumption behaviours in a FSR setting. In the twin disc setting, the normal pressure affects the consumption behaviour. The experimental data provided the basis for development of a model that allows predictions of the friction behaviour for wayside application of top-of-rail products as a function of distance to the application site and the number of wheel passes.
-
wheel rail Creep Force model for predicting water induced low adhesion phenomena
Tribology International, 2017Co-Authors: Gerald Trummer, Petr Voltr, L E Buckleyjohnstone, Roger Lewis, Alexander Meierhofer, Klaus SixAbstract:A computationally efficient engineering model to predict adhesion in rolling contact in the presence of water is presented which may be implemented in multibody dynamics software or in braking models to study train performance and braking strategies. This model has been developed in a project funded by the Rail Safety and Standards Board (RSSB) and Network Rail. It is referred to as the water-induced low adhesion Creep Force (WILAC) model. The model covers a wide range of conditions from dry over damp to wet. Special emphasis is put on little amounts of water which can cause low adhesion without any oil or grease. Such conditions may be encountered in humid weather or at the onset of rain. The model is parameterised based on experimental results from a tram wheel test rig. Adhesion values as low as 0.06 are observed at high Creep with only wear debris and little water present in the contact. The model results also agree with experimental data from locomotive tests in dry and wet conditions.