Optimal Selection of the Mother Wavelet in WPT Analysis and Its Influence in Cracked Railway Axles Detection

The detection of cracked railway axles by processing vibratory signals measured during operation is the focus of this study. The rotodynamic theory is applied to this specific purpose but, in practice and for real systems, there is no consensus on applying the results obtained from theory. Finding r...

Full description

Bibliographic Details
Main Authors: Marta Zamorano, María Jesús Gómez, Cristina Castejón
Format: Article
Language:English
Published: MDPI AG 2023-04-01
Series:Machines
Subjects:
Online Access:https://www.mdpi.com/2075-1702/11/4/493
_version_ 1797604617217900544
author Marta Zamorano
María Jesús Gómez
Cristina Castejón
author_facet Marta Zamorano
María Jesús Gómez
Cristina Castejón
author_sort Marta Zamorano
collection DOAJ
description The detection of cracked railway axles by processing vibratory signals measured during operation is the focus of this study. The rotodynamic theory is applied to this specific purpose but, in practice and for real systems, there is no consensus on applying the results obtained from theory. Finding reliable patterns that change during operation would have advantages over other currently applied methods, such as non-destructive testing (NDT) techniques, because data between inspections would be obtained during operation. Vibratory signal processing techniques in the time-frequency domain, such as wavelet packet transform (WPT), have proved to be reliable to obtain patterns. The aim of this work is to develop a methodology to select the optimal function associated with the WPT, the mother wavelet (MW), and to find diagnostic patterns for cracked railway axle detection. In previous related works, the Daubechies 6 MW was commonly used for all speed/load conditions and defects. In this work, it was found that the Symlet 9 MW works better, so a comparative study was carried out with both functions, and it was observed that the success rates obtained with Daubechies 6 are improved when using Symlet 9. Specifically, defects above 16.6% of the shaft diameter were reliably detected, with no false alarms. To validate the proposed methodology, experimental vibratory signals of a healthy scaled railway axle were obtained and then the same axle was tested with a transverse crack located close to a section change (where this type of defect typically appears) for nine different crack depths.
first_indexed 2024-03-11T04:49:17Z
format Article
id doaj.art-9dea81831c0147fea5c94f6a8b7b28cb
institution Directory Open Access Journal
issn 2075-1702
language English
last_indexed 2024-03-11T04:49:17Z
publishDate 2023-04-01
publisher MDPI AG
record_format Article
series Machines
spelling doaj.art-9dea81831c0147fea5c94f6a8b7b28cb2023-11-17T20:09:23ZengMDPI AGMachines2075-17022023-04-0111449310.3390/machines11040493Optimal Selection of the Mother Wavelet in WPT Analysis and Its Influence in Cracked Railway Axles DetectionMarta Zamorano0María Jesús Gómez1Cristina Castejón2MAQLAB Group, Mechanical Engineering Department, Universidad Carlos III de Madrid, Av. de la Universidad 30, 28911 Leganés, SpainMAQLAB Group, Mechanical Engineering Department, Universidad Carlos III de Madrid, Av. de la Universidad 30, 28911 Leganés, SpainMAQLAB Group, Mechanical Engineering Department, Universidad Carlos III de Madrid, Av. de la Universidad 30, 28911 Leganés, SpainThe detection of cracked railway axles by processing vibratory signals measured during operation is the focus of this study. The rotodynamic theory is applied to this specific purpose but, in practice and for real systems, there is no consensus on applying the results obtained from theory. Finding reliable patterns that change during operation would have advantages over other currently applied methods, such as non-destructive testing (NDT) techniques, because data between inspections would be obtained during operation. Vibratory signal processing techniques in the time-frequency domain, such as wavelet packet transform (WPT), have proved to be reliable to obtain patterns. The aim of this work is to develop a methodology to select the optimal function associated with the WPT, the mother wavelet (MW), and to find diagnostic patterns for cracked railway axle detection. In previous related works, the Daubechies 6 MW was commonly used for all speed/load conditions and defects. In this work, it was found that the Symlet 9 MW works better, so a comparative study was carried out with both functions, and it was observed that the success rates obtained with Daubechies 6 are improved when using Symlet 9. Specifically, defects above 16.6% of the shaft diameter were reliably detected, with no false alarms. To validate the proposed methodology, experimental vibratory signals of a healthy scaled railway axle were obtained and then the same axle was tested with a transverse crack located close to a section change (where this type of defect typically appears) for nine different crack depths.https://www.mdpi.com/2075-1702/11/4/493mother waveletwavelet packet transformvibration analysiscondition monitoringrailway axlescrack detection
spellingShingle Marta Zamorano
María Jesús Gómez
Cristina Castejón
Optimal Selection of the Mother Wavelet in WPT Analysis and Its Influence in Cracked Railway Axles Detection
Machines
mother wavelet
wavelet packet transform
vibration analysis
condition monitoring
railway axles
crack detection
title Optimal Selection of the Mother Wavelet in WPT Analysis and Its Influence in Cracked Railway Axles Detection
title_full Optimal Selection of the Mother Wavelet in WPT Analysis and Its Influence in Cracked Railway Axles Detection
title_fullStr Optimal Selection of the Mother Wavelet in WPT Analysis and Its Influence in Cracked Railway Axles Detection
title_full_unstemmed Optimal Selection of the Mother Wavelet in WPT Analysis and Its Influence in Cracked Railway Axles Detection
title_short Optimal Selection of the Mother Wavelet in WPT Analysis and Its Influence in Cracked Railway Axles Detection
title_sort optimal selection of the mother wavelet in wpt analysis and its influence in cracked railway axles detection
topic mother wavelet
wavelet packet transform
vibration analysis
condition monitoring
railway axles
crack detection
url https://www.mdpi.com/2075-1702/11/4/493
work_keys_str_mv AT martazamorano optimalselectionofthemotherwaveletinwptanalysisanditsinfluenceincrackedrailwayaxlesdetection
AT mariajesusgomez optimalselectionofthemotherwaveletinwptanalysisanditsinfluenceincrackedrailwayaxlesdetection
AT cristinacastejon optimalselectionofthemotherwaveletinwptanalysisanditsinfluenceincrackedrailwayaxlesdetection