A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance
Coated conductive structures are widely adopted in such engineering fields as aerospace, nuclear energy, etc. The hostile and corrosive environment leaves in-service coated conductive structures vulnerable to Hidden Material Degradation (HMD) occurring under the protection coating. It is highly dema...
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| Format: | Article |
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MDPI AG
2017-04-01
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| Series: | Sensors |
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| Online Access: | http://www.mdpi.com/1424-8220/17/5/943 |
| _version_ | 1811213313299709952 |
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| author | Yong Li Haoqing Jing Ilham Mukriz Zainal Abidin Bei Yan |
| author_facet | Yong Li Haoqing Jing Ilham Mukriz Zainal Abidin Bei Yan |
| author_sort | Yong Li |
| collection | DOAJ |
| description | Coated conductive structures are widely adopted in such engineering fields as aerospace, nuclear energy, etc. The hostile and corrosive environment leaves in-service coated conductive structures vulnerable to Hidden Material Degradation (HMD) occurring under the protection coating. It is highly demanded that HMD can be non-intrusively assessed using non-destructive evaluation techniques. In light of the advantages of Gradient-field Pulsed Eddy Current technique (GPEC) over other non-destructive evaluation methods in corrosion evaluation, in this paper the GPEC probe for quantitative evaluation of HMD is intensively investigated. Closed-form expressions of GPEC responses to HMD are formulated via analytical modeling. The Lift-off Invariance (LOI) in GPEC signals, which makes the HMD evaluation immune to the variation in thickness of the protection coating, is introduced and analyzed through simulations involving HMD with variable depths and conductivities. A fast inverse method employing magnitude and time of the LOI point in GPEC signals for simultaneously evaluating the conductivity and thickness of HMD region is proposed, and subsequently verified by finite element modeling and experiments. It has been found from the results that along with the proposed inverse method the GPEC probe is applicable to evaluation of HMD in coated conductive structures without much loss in accuracy. |
| first_indexed | 2024-04-12T05:44:44Z |
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| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-12T05:44:44Z |
| publishDate | 2017-04-01 |
| publisher | MDPI AG |
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| series | Sensors |
| spelling | doaj.art-e43f31ecf79040c2a9153aa545391c052022-12-22T03:45:30ZengMDPI AGSensors1424-82202017-04-0117594310.3390/s17050943s17050943A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off InvarianceYong Li0Haoqing Jing1Ilham Mukriz Zainal Abidin2Bei Yan3State Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Engineering Research Center of NDT and Structural Integrity Evaluation, Xi’an Jiaotong University, Xi’an 710049, ChinaState Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Engineering Research Center of NDT and Structural Integrity Evaluation, Xi’an Jiaotong University, Xi’an 710049, ChinaLeading Edge NDT Technology (LENDT) Group, Malaysian Nuclear Agency, 43000 Bangi, Kajang, Selangor, MalaysiaState Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Engineering Research Center of NDT and Structural Integrity Evaluation, Xi’an Jiaotong University, Xi’an 710049, ChinaCoated conductive structures are widely adopted in such engineering fields as aerospace, nuclear energy, etc. The hostile and corrosive environment leaves in-service coated conductive structures vulnerable to Hidden Material Degradation (HMD) occurring under the protection coating. It is highly demanded that HMD can be non-intrusively assessed using non-destructive evaluation techniques. In light of the advantages of Gradient-field Pulsed Eddy Current technique (GPEC) over other non-destructive evaluation methods in corrosion evaluation, in this paper the GPEC probe for quantitative evaluation of HMD is intensively investigated. Closed-form expressions of GPEC responses to HMD are formulated via analytical modeling. The Lift-off Invariance (LOI) in GPEC signals, which makes the HMD evaluation immune to the variation in thickness of the protection coating, is introduced and analyzed through simulations involving HMD with variable depths and conductivities. A fast inverse method employing magnitude and time of the LOI point in GPEC signals for simultaneously evaluating the conductivity and thickness of HMD region is proposed, and subsequently verified by finite element modeling and experiments. It has been found from the results that along with the proposed inverse method the GPEC probe is applicable to evaluation of HMD in coated conductive structures without much loss in accuracy.http://www.mdpi.com/1424-8220/17/5/943electromagnetic non-destructive evaluationgradient-field pulsed eddy current probelift-off invariancematerial degradationinversioncoated conductive structures |
| spellingShingle | Yong Li Haoqing Jing Ilham Mukriz Zainal Abidin Bei Yan A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance Sensors electromagnetic non-destructive evaluation gradient-field pulsed eddy current probe lift-off invariance material degradation inversion coated conductive structures |
| title | A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance |
| title_full | A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance |
| title_fullStr | A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance |
| title_full_unstemmed | A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance |
| title_short | A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance |
| title_sort | gradient field pulsed eddy current probe for evaluation of hidden material degradation in conductive structures based on lift off invariance |
| topic | electromagnetic non-destructive evaluation gradient-field pulsed eddy current probe lift-off invariance material degradation inversion coated conductive structures |
| url | http://www.mdpi.com/1424-8220/17/5/943 |
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