Exploring Step-Heating and Lock-In Thermography NDT Using One-Sided Inspection on Low-Emissivity Composite Structures for New Rail Carbodies
This paper aims to explore the qualification of step- and lock-in heating thermography as techniques capable of inspecting new composite rail carbodies following input and inspection requirements set by the rail manufacturing industry. Specifically, we studied (a) a monolithic CFRP sample (20 mm thi...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-10-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/22/21/8195 |
| _version_ | 1827645477414240256 |
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| author | Alkiviadis Tromaras Vassilios Kappatos |
| author_facet | Alkiviadis Tromaras Vassilios Kappatos |
| author_sort | Alkiviadis Tromaras |
| collection | DOAJ |
| description | This paper aims to explore the qualification of step- and lock-in heating thermography as techniques capable of inspecting new composite rail carbodies following input and inspection requirements set by the rail manufacturing industry. Specifically, we studied (a) a monolithic CFRP sample (20 mm thickness) and (b) a CFRP–PET foam–CFRP sandwich (40 mm total thickness) component, that were manufactured with artificial defects, to replicate the side wall sections of a carbody. The samples proved to be very challenging to test using only one-sided inspection due to (1) exhibiting significant thickness compared to existing literature, (2) low surface emissivity and (3) that the foam core of the sandwich sample was a thermal insulating material. In addition, the sandwich sample was designed with defects on both skins. Both thermography techniques provided similar defect detection results, although step heating offered faster detection. In the case of the monolithic panel, defects up to 10 mm depth were detected, with minor detection of defects at 15 mm depth with a step-heating protocol between 90 s and 120 s overall acquisition, which was faster than the 140 s used with the lock-in technique. For the sandwich component only the front skin defects were detected, with both techniques using heating protocols between 70–120 s. |
| first_indexed | 2024-03-09T18:40:47Z |
| format | Article |
| id | doaj.art-1ace8e33fd884b648d2561a0d2d8af0a |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-09T18:40:47Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-1ace8e33fd884b648d2561a0d2d8af0a2023-11-24T06:44:12ZengMDPI AGSensors1424-82202022-10-012221819510.3390/s22218195Exploring Step-Heating and Lock-In Thermography NDT Using One-Sided Inspection on Low-Emissivity Composite Structures for New Rail CarbodiesAlkiviadis Tromaras0Vassilios Kappatos1Centre for Research and Technology Hellas, Hellenic Institute of Transport, 6th Km Charilaou-Thermi Road, 57001 Thessaloniki, GreeceCentre for Research and Technology Hellas, Hellenic Institute of Transport, 6th Km Charilaou-Thermi Road, 57001 Thessaloniki, GreeceThis paper aims to explore the qualification of step- and lock-in heating thermography as techniques capable of inspecting new composite rail carbodies following input and inspection requirements set by the rail manufacturing industry. Specifically, we studied (a) a monolithic CFRP sample (20 mm thickness) and (b) a CFRP–PET foam–CFRP sandwich (40 mm total thickness) component, that were manufactured with artificial defects, to replicate the side wall sections of a carbody. The samples proved to be very challenging to test using only one-sided inspection due to (1) exhibiting significant thickness compared to existing literature, (2) low surface emissivity and (3) that the foam core of the sandwich sample was a thermal insulating material. In addition, the sandwich sample was designed with defects on both skins. Both thermography techniques provided similar defect detection results, although step heating offered faster detection. In the case of the monolithic panel, defects up to 10 mm depth were detected, with minor detection of defects at 15 mm depth with a step-heating protocol between 90 s and 120 s overall acquisition, which was faster than the 140 s used with the lock-in technique. For the sandwich component only the front skin defects were detected, with both techniques using heating protocols between 70–120 s.https://www.mdpi.com/1424-8220/22/21/8195step heatinglock-in heatingthermographyinfrared thermographycomposite rail carbodiesCF-PET-CF sandwich |
| spellingShingle | Alkiviadis Tromaras Vassilios Kappatos Exploring Step-Heating and Lock-In Thermography NDT Using One-Sided Inspection on Low-Emissivity Composite Structures for New Rail Carbodies Sensors step heating lock-in heating thermography infrared thermography composite rail carbodies CF-PET-CF sandwich |
| title | Exploring Step-Heating and Lock-In Thermography NDT Using One-Sided Inspection on Low-Emissivity Composite Structures for New Rail Carbodies |
| title_full | Exploring Step-Heating and Lock-In Thermography NDT Using One-Sided Inspection on Low-Emissivity Composite Structures for New Rail Carbodies |
| title_fullStr | Exploring Step-Heating and Lock-In Thermography NDT Using One-Sided Inspection on Low-Emissivity Composite Structures for New Rail Carbodies |
| title_full_unstemmed | Exploring Step-Heating and Lock-In Thermography NDT Using One-Sided Inspection on Low-Emissivity Composite Structures for New Rail Carbodies |
| title_short | Exploring Step-Heating and Lock-In Thermography NDT Using One-Sided Inspection on Low-Emissivity Composite Structures for New Rail Carbodies |
| title_sort | exploring step heating and lock in thermography ndt using one sided inspection on low emissivity composite structures for new rail carbodies |
| topic | step heating lock-in heating thermography infrared thermography composite rail carbodies CF-PET-CF sandwich |
| url | https://www.mdpi.com/1424-8220/22/21/8195 |
| work_keys_str_mv | AT alkiviadistromaras exploringstepheatingandlockinthermographyndtusingonesidedinspectiononlowemissivitycompositestructuresfornewrailcarbodies AT vassilioskappatos exploringstepheatingandlockinthermographyndtusingonesidedinspectiononlowemissivitycompositestructuresfornewrailcarbodies |