The Experts below are selected from a list of 15006 Experts worldwide ranked by ideXlab platform

P.b. Kosasih - One of the best experts on this subject based on the ideXlab platform.

  • fe method to predict damage formation on curved track for various worn status of wheel rail profiles
    Wear, 2015
    Co-Authors: A. Kiet Tieu, Hongtao Zhu, P.b. Kosasih
    Abstract:

    Abstract In wheel/rail contact, rolling phenomenon on the curved track can be much more complicated than that on the straight track, especially on a sharp curved track. Due to the influences of super-elevation (also called track cant), angle of attack (AOA) and rail cant, stress states on the high rail are significantly different from that on the low rail. Therefore, the appearances of damages on the low and high rails are different as well. These damages can result in the rail failures, subsequently leading to the vehicle derailments. In this paper, a realistic finite element model using Australian wheel/rail profiles (ANZR1 wheel and 60 kg rail) was developed to investigate the wheel/rail contact on the low and high rail of a curved track under high Adhesion Condition. Based on the datum of contact stress states, surface damage mechanisms of the rail in curved track was determined. The new and worn profiles were utilized in the simulation to examine different contact situations: new wheel/new rail, new wheel/worn rail, and worn wheel/worn rail contacts. The obtained results showed that the two-point contact might appear on the high rail of the curved track and the stress distributions at each contact location were varied depending on the contact location and AOA. Moreover, the response of material at the rail head was predicted to be ratchetting. Regarding the damage predictions, the rail corrugation tended to be formed on the low rail rather than the high rail; and the fatigue defects could be easier developed on the standard carbon rail compared with hardened rail.

  • FE method to predict damage formation on curved track for various worn status of wheel/rail profiles
    Wear, 2015
    Co-Authors: K. D. Vo, H T Zhu, A. Kiet Tieu, P.b. Kosasih
    Abstract:

    In wheel/rail contact, rolling phenomenon on the curved track can be much more complicated than that on the straight track, especially on a sharp curved track. Due to the influences of super-elevation (also called track cant), angle of attack (AOA) and rail cant, stress states on the high rail are significantly different from that on the low rail. Therefore, the appearances of damages on the low and high rails are different as well. These damages can result in the rail failures, subsequently leading to the vehicle derailments. In this paper, a realistic finite element model using Australian wheel/rail profiles (ANZR1 wheel and 60. kg rail) was developed to investigate the wheel/rail contact on the low and high rail of a curved track under high Adhesion Condition. Based on the datum of contact stress states, surface damage mechanisms of the rail in curved track was determined. The new and worn profiles were utilized in the simulation to examine different contact situations: new wheel/new rail, new wheel/worn rail, and worn wheel/worn rail contacts. The obtained results showed that the two-point contact might appear on the high rail of the curved track and the stress distributions at each contact location were varied depending on the contact location and AOA. Moreover, the response of material at the rail head was predicted to be ratchetting. Regarding the damage predictions, the rail corrugation tended to be formed on the low rail rather than the high rail; and the fatigue defects could be easier developed on the standard carbon rail compared with hardened rail.

Benedetto Allotta - One of the best experts on this subject based on the ideXlab platform.

  • Performance and robustness analysis of a Hardware In the Loop full-scale roller-rig for railway braking and traction testing
    Meccanica, 2014
    Co-Authors: Benedetto Allotta, Enrico Meli, Roberto Conti, Luca Pugi, Alessandro Ridolfi
    Abstract:

    Traditionally, braking and traction on-board subsystems, such as traction systems, braking plants and safety subsystems (e.g. WSP devices) can be tested and verified through fullscale roller-rigs, to avoid expensive on-track tests. In this work the authors investigate the test-rig built in the research center “Centro di Dinamica Sperimentale Osmannoro-Firenze (CDSO)” by Rete Ferroviaria Italiana (RFI), in which the braking and traction systems are tested using an innovative Hardware In the Loop (HIL) architecture able to perform the simulation of a known wheel-rail Adhesion pattern (in particular degraded Adhesion Condition). The objective of this work is to study, starting from the knowledge of the system characteristics, the performances and the robustness of the HIL architecture during a simulation of braking and traction phases under degraded Adhesion Conditions. This work has been developed in collaboration with Italcertifer S.p.a. and Trenitalia S.p.a. that provided the technical data of the test rig and the considered railway vehicle (the E464 locomotive).

  • innovative management of wheel rail Adhesion Conditions in localization algorithms for the automatic train protection
    Chemical engineering transactions, 2013
    Co-Authors: Enrique De La Cal, Filippo Salotti, Gregorio Vettori, Luca Pugi, Benedetto Allotta, Alessandro Ridolfi, Ng Tran, Monica Malvezzi, Loretta Landi
    Abstract:

    In the modern railway network, Automatic Train Protection and Control (ATP-ATC) systems are fundamental to increase the infrastructure capacity, maintaining a proper level of operation safety. Odometry is a relevant on-board module, since it estimates the speed and the travelled distance of a railway vehicle along the track. Its reliability affects the definition of allowed speed profiles, in order to prevent collisions from a driver's failure to observe a signal. Typically the dead reckoning relies on encoders providing an accurate estimation of the train speed only when good Adhesion Conditions between wheel and rail occur. In presence of wheel sliding the estimation error may become very high. In this paper the management of Adhesion Conditions is enhanced using an Inertial Measurement Unit (IMU) which improves the Adhesion Condition detection and the speed and travelled distance estimation. The testing of the proposed algorithm is performed through a testing simulator, set up by the MDM Lab and used to speed up the algorithm tuning, capable of replicating in a realistic way the motion dynamic effects of a railway vehicle on inertial sensors. The Hardware-In-The-Loop test rig is composed of a Matlab-Simulink TM three-dimensional multibody model of a railway vehicle, a commercial anthropomorphic manipulator with spherical wrist and an IMU designed by ECM Spa (Pistoia, Italy). The experimental results are compared to the performance requirements fixed by the European Rail Traffic Management System (ERTMS).

  • a numerical model of a hil scaled roller rig for simulation of wheel rail degraded Adhesion Condition
    Vehicle System Dynamics, 2012
    Co-Authors: Roberto Conti, Enrico Meli, Luca Pugi, Benedetto Allotta, Monica Malvezzi, Fabio Bartolini, Andrea Rindi, P Toni
    Abstract:

    Scaled roller rigs used for railway applications play a fundamental role in the development of new technologies and new devices, combining the hardware in the loop (HIL) benefits with the reduction of the economic investments. The main problem of the scaled roller rig with respect to the full scale ones is the improved complexity due to the scaling factors. For this reason, before building the test rig, the development of a software model of the HIL system can be useful to analyse the system behaviour in different operative Conditions. One has to consider the multi-body behaviour of the scaled roller rig, the controller and the model of the virtual vehicle, whose dynamics has to be reproduced on the rig. The main purpose of this work is the development of a complete model that satisfies the previous requirements and in particular the performance analysis of the controller and of the dynamical behaviour of the scaled roller rig when some disturbances are simulated with low Adhesion Conditions. Since the sc...

K. D. Vo - One of the best experts on this subject based on the ideXlab platform.

  • FE method to predict damage formation on curved track for various worn status of wheel/rail profiles
    Wear, 2015
    Co-Authors: K. D. Vo, H T Zhu, A. Kiet Tieu, P.b. Kosasih
    Abstract:

    In wheel/rail contact, rolling phenomenon on the curved track can be much more complicated than that on the straight track, especially on a sharp curved track. Due to the influences of super-elevation (also called track cant), angle of attack (AOA) and rail cant, stress states on the high rail are significantly different from that on the low rail. Therefore, the appearances of damages on the low and high rails are different as well. These damages can result in the rail failures, subsequently leading to the vehicle derailments. In this paper, a realistic finite element model using Australian wheel/rail profiles (ANZR1 wheel and 60. kg rail) was developed to investigate the wheel/rail contact on the low and high rail of a curved track under high Adhesion Condition. Based on the datum of contact stress states, surface damage mechanisms of the rail in curved track was determined. The new and worn profiles were utilized in the simulation to examine different contact situations: new wheel/new rail, new wheel/worn rail, and worn wheel/worn rail contacts. The obtained results showed that the two-point contact might appear on the high rail of the curved track and the stress distributions at each contact location were varied depending on the contact location and AOA. Moreover, the response of material at the rail head was predicted to be ratchetting. Regarding the damage predictions, the rail corrugation tended to be formed on the low rail rather than the high rail; and the fatigue defects could be easier developed on the standard carbon rail compared with hardened rail.

A. Kiet Tieu - One of the best experts on this subject based on the ideXlab platform.

  • fe method to predict damage formation on curved track for various worn status of wheel rail profiles
    Wear, 2015
    Co-Authors: A. Kiet Tieu, Hongtao Zhu, P.b. Kosasih
    Abstract:

    Abstract In wheel/rail contact, rolling phenomenon on the curved track can be much more complicated than that on the straight track, especially on a sharp curved track. Due to the influences of super-elevation (also called track cant), angle of attack (AOA) and rail cant, stress states on the high rail are significantly different from that on the low rail. Therefore, the appearances of damages on the low and high rails are different as well. These damages can result in the rail failures, subsequently leading to the vehicle derailments. In this paper, a realistic finite element model using Australian wheel/rail profiles (ANZR1 wheel and 60 kg rail) was developed to investigate the wheel/rail contact on the low and high rail of a curved track under high Adhesion Condition. Based on the datum of contact stress states, surface damage mechanisms of the rail in curved track was determined. The new and worn profiles were utilized in the simulation to examine different contact situations: new wheel/new rail, new wheel/worn rail, and worn wheel/worn rail contacts. The obtained results showed that the two-point contact might appear on the high rail of the curved track and the stress distributions at each contact location were varied depending on the contact location and AOA. Moreover, the response of material at the rail head was predicted to be ratchetting. Regarding the damage predictions, the rail corrugation tended to be formed on the low rail rather than the high rail; and the fatigue defects could be easier developed on the standard carbon rail compared with hardened rail.

  • FE method to predict damage formation on curved track for various worn status of wheel/rail profiles
    Wear, 2015
    Co-Authors: K. D. Vo, H T Zhu, A. Kiet Tieu, P.b. Kosasih
    Abstract:

    In wheel/rail contact, rolling phenomenon on the curved track can be much more complicated than that on the straight track, especially on a sharp curved track. Due to the influences of super-elevation (also called track cant), angle of attack (AOA) and rail cant, stress states on the high rail are significantly different from that on the low rail. Therefore, the appearances of damages on the low and high rails are different as well. These damages can result in the rail failures, subsequently leading to the vehicle derailments. In this paper, a realistic finite element model using Australian wheel/rail profiles (ANZR1 wheel and 60. kg rail) was developed to investigate the wheel/rail contact on the low and high rail of a curved track under high Adhesion Condition. Based on the datum of contact stress states, surface damage mechanisms of the rail in curved track was determined. The new and worn profiles were utilized in the simulation to examine different contact situations: new wheel/new rail, new wheel/worn rail, and worn wheel/worn rail contacts. The obtained results showed that the two-point contact might appear on the high rail of the curved track and the stress distributions at each contact location were varied depending on the contact location and AOA. Moreover, the response of material at the rail head was predicted to be ratchetting. Regarding the damage predictions, the rail corrugation tended to be formed on the low rail rather than the high rail; and the fatigue defects could be easier developed on the standard carbon rail compared with hardened rail.

Alessandro Ridolfi - One of the best experts on this subject based on the ideXlab platform.

  • Performance and robustness analysis of a Hardware In the Loop full-scale roller-rig for railway braking and traction testing
    Meccanica, 2014
    Co-Authors: Benedetto Allotta, Enrico Meli, Roberto Conti, Luca Pugi, Alessandro Ridolfi
    Abstract:

    Traditionally, braking and traction on-board subsystems, such as traction systems, braking plants and safety subsystems (e.g. WSP devices) can be tested and verified through fullscale roller-rigs, to avoid expensive on-track tests. In this work the authors investigate the test-rig built in the research center “Centro di Dinamica Sperimentale Osmannoro-Firenze (CDSO)” by Rete Ferroviaria Italiana (RFI), in which the braking and traction systems are tested using an innovative Hardware In the Loop (HIL) architecture able to perform the simulation of a known wheel-rail Adhesion pattern (in particular degraded Adhesion Condition). The objective of this work is to study, starting from the knowledge of the system characteristics, the performances and the robustness of the HIL architecture during a simulation of braking and traction phases under degraded Adhesion Conditions. This work has been developed in collaboration with Italcertifer S.p.a. and Trenitalia S.p.a. that provided the technical data of the test rig and the considered railway vehicle (the E464 locomotive).

  • innovative management of wheel rail Adhesion Conditions in localization algorithms for the automatic train protection
    Chemical engineering transactions, 2013
    Co-Authors: Enrique De La Cal, Filippo Salotti, Gregorio Vettori, Luca Pugi, Benedetto Allotta, Alessandro Ridolfi, Ng Tran, Monica Malvezzi, Loretta Landi
    Abstract:

    In the modern railway network, Automatic Train Protection and Control (ATP-ATC) systems are fundamental to increase the infrastructure capacity, maintaining a proper level of operation safety. Odometry is a relevant on-board module, since it estimates the speed and the travelled distance of a railway vehicle along the track. Its reliability affects the definition of allowed speed profiles, in order to prevent collisions from a driver's failure to observe a signal. Typically the dead reckoning relies on encoders providing an accurate estimation of the train speed only when good Adhesion Conditions between wheel and rail occur. In presence of wheel sliding the estimation error may become very high. In this paper the management of Adhesion Conditions is enhanced using an Inertial Measurement Unit (IMU) which improves the Adhesion Condition detection and the speed and travelled distance estimation. The testing of the proposed algorithm is performed through a testing simulator, set up by the MDM Lab and used to speed up the algorithm tuning, capable of replicating in a realistic way the motion dynamic effects of a railway vehicle on inertial sensors. The Hardware-In-The-Loop test rig is composed of a Matlab-Simulink TM three-dimensional multibody model of a railway vehicle, a commercial anthropomorphic manipulator with spherical wrist and an IMU designed by ECM Spa (Pistoia, Italy). The experimental results are compared to the performance requirements fixed by the European Rail Traffic Management System (ERTMS).