Examinando por Autor "Castaneda, Leonel F."

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    A fractional Fourier transform-based method to detect impacts between the bogie and the car body of a railway vehicle: A data-driven approach
    (SAGE PUBLICATIONS LTD, 2018-01-01) Gutierrez-Carvajal, R. E.; Betancur, German R.; Castaneda, Leonel F.; Zajac, G.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
    Structural railway transport elements are typically designed to work for at least 30 years without undergoing major maintenance. However, real-life operational conditions present behaviors different to the model predicted during the initial design phase, which affects the lifetime of the elements in question. This is the case of first-generation railway vehicles which operates in the city of Medellín, Colombia, as the bolster beam presented cracks after 12 years of operation, possibly due to undesired impacts between the bogie and the pivot of the bolster beam. Monitoring vibrational signals would give some sort of an insight into impact phenomena; however, herein lies the problem, as they are difficult to identify using only vibration signals, occurring during time events that take place in a speed-varying system. In this article, the authors present a technique that automatically detects impacts using multiple in-between time/frequency representations, ranking them according to their capacity to discriminate between impact events. Our results show that the best representation for this data was the Fractional Cepstrum Transform at order 0.5 (auROC = 0.961), which outperformed the best pure domain descriptor by least 4%. © 2016, © IMechE 2016.
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    A study of the effect of the transition curve in the coupling elements between the carbody and the bogie
    (INDERSCIENCE ENTERPRISES LTD, 2014-01-01) Martinod, Ronald M.; Betancur, German R.; Osorio, Jose F.; Castaneda, Leonel F.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
    This work describes an analysis of the effect of the transition curves in the coupling elements between the carbody and the bogie, by means of recorded variables under commercial operation conditions of a railway vehicle. A set of field tests are developed and applied to the railway system as a basis to validate a numerical model. The dataset is obtained from a numerical model based on the multi-body systems theory using a transient method. The study focuses on the dynamic evaluation of the vehicle to determine the transversal dynamic effect generated by the circulation in the transition curve sections, especially in curves with short radius. The work includes a case study of a passenger railway, and it is used to identify aspects of the railway system that could be improved by the operators, such as inspection routines, rail track design and elements subjected to considerable loads. Copyright © 2014 Inderscience Enterprises Ltd.