Terahertz Spectroscopic Characterization and Thickness Evaluation of Internal Delamination Defects in GFRP Composites
Abstract The use of terahertz time-domain spectroscopy (THz-TDS) for the nondestructive testing and evaluation (NDT&E) of materials and structural systems has attracted significant attention over the past two decades due to its superior spatial resolution and capabilities of detecting and charac...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2023-01-01
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| Series: | Chinese Journal of Mechanical Engineering |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s10033-022-00829-7 |
| _version_ | 1797946001877630976 |
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| author | Walter Nsengiyumva Shuncong Zhong Manting Luo Bing Wang |
| author_facet | Walter Nsengiyumva Shuncong Zhong Manting Luo Bing Wang |
| author_sort | Walter Nsengiyumva |
| collection | DOAJ |
| description | Abstract The use of terahertz time-domain spectroscopy (THz-TDS) for the nondestructive testing and evaluation (NDT&E) of materials and structural systems has attracted significant attention over the past two decades due to its superior spatial resolution and capabilities of detecting and characterizing defects and structural damage in non-conducting materials. In this study, the THz-TDS system is used to detect, localize and evaluate hidden multi-delamination defects (i.e., a three-level multi-delamination system) in multilayered GFRP composite laminates. To obtain accurate results, a wavelet shrinkage de-noising algorithm is used to remove the noise from the measured time-of-flight (TOF) signals. The thickness and location of each delamination defect in the z-direction (i.e., through-the-thickness direction) are calculated from the de-noised TOF signals considering the interaction between the pulsed THz waves and the different interfaces in the GFRP composite laminates. A comparison between the actual and the measured thickness values of the delamination defects before and after the wavelet shrinkage denoising process indicates that the latter provides better results with less than 3.712% relative error, while the relative error of the non-de-noised signals reaches 16.388%. Also, the power and absorbance levels of the THz waves at every interface with different refractive indices in the GFRP composite laminates are evaluated based on analytical and experimental approaches. The present study provides an adequate theoretical analysis that could help NDT&E specialists to estimate the maximum thickness of GFRP composite materials and/or structures with different interfaces that can be evaluated by the THz-TDS. Also, the accuracy of the obtained results highlights the capabilities of the THz-TDS for the NDT&E of multilayered GFRP composite laminates. |
| first_indexed | 2024-04-10T21:03:58Z |
| format | Article |
| id | doaj.art-220a5accb2254d0d88c82c5cdb9eef08 |
| institution | Directory Open Access Journal |
| issn | 2192-8258 |
| language | English |
| last_indexed | 2024-04-10T21:03:58Z |
| publishDate | 2023-01-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Chinese Journal of Mechanical Engineering |
| spelling | doaj.art-220a5accb2254d0d88c82c5cdb9eef082023-01-22T12:06:31ZengSpringerOpenChinese Journal of Mechanical Engineering2192-82582023-01-0136112110.1186/s10033-022-00829-7Terahertz Spectroscopic Characterization and Thickness Evaluation of Internal Delamination Defects in GFRP CompositesWalter Nsengiyumva0Shuncong Zhong1Manting Luo2Bing Wang3Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing, School of Mechanical Engineering and Automation, Fuzhou UniversityFujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing, School of Mechanical Engineering and Automation, Fuzhou UniversitySchool of Mechanical and Electrical Engineering, Putian UniversityFujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing, School of Mechanical Engineering and Automation, Fuzhou UniversityAbstract The use of terahertz time-domain spectroscopy (THz-TDS) for the nondestructive testing and evaluation (NDT&E) of materials and structural systems has attracted significant attention over the past two decades due to its superior spatial resolution and capabilities of detecting and characterizing defects and structural damage in non-conducting materials. In this study, the THz-TDS system is used to detect, localize and evaluate hidden multi-delamination defects (i.e., a three-level multi-delamination system) in multilayered GFRP composite laminates. To obtain accurate results, a wavelet shrinkage de-noising algorithm is used to remove the noise from the measured time-of-flight (TOF) signals. The thickness and location of each delamination defect in the z-direction (i.e., through-the-thickness direction) are calculated from the de-noised TOF signals considering the interaction between the pulsed THz waves and the different interfaces in the GFRP composite laminates. A comparison between the actual and the measured thickness values of the delamination defects before and after the wavelet shrinkage denoising process indicates that the latter provides better results with less than 3.712% relative error, while the relative error of the non-de-noised signals reaches 16.388%. Also, the power and absorbance levels of the THz waves at every interface with different refractive indices in the GFRP composite laminates are evaluated based on analytical and experimental approaches. The present study provides an adequate theoretical analysis that could help NDT&E specialists to estimate the maximum thickness of GFRP composite materials and/or structures with different interfaces that can be evaluated by the THz-TDS. Also, the accuracy of the obtained results highlights the capabilities of the THz-TDS for the NDT&E of multilayered GFRP composite laminates.https://doi.org/10.1186/s10033-022-00829-7Glass-fiber-reinforced polymer-matrix (GFRP) compositesTerahertz time-domain spectroscopy (THz-TDS)Nondestructive testing and evaluation (NDT&E)Stationary wavelet transform (SWT)Thickness evaluationDelamination defects |
| spellingShingle | Walter Nsengiyumva Shuncong Zhong Manting Luo Bing Wang Terahertz Spectroscopic Characterization and Thickness Evaluation of Internal Delamination Defects in GFRP Composites Chinese Journal of Mechanical Engineering Glass-fiber-reinforced polymer-matrix (GFRP) composites Terahertz time-domain spectroscopy (THz-TDS) Nondestructive testing and evaluation (NDT&E) Stationary wavelet transform (SWT) Thickness evaluation Delamination defects |
| title | Terahertz Spectroscopic Characterization and Thickness Evaluation of Internal Delamination Defects in GFRP Composites |
| title_full | Terahertz Spectroscopic Characterization and Thickness Evaluation of Internal Delamination Defects in GFRP Composites |
| title_fullStr | Terahertz Spectroscopic Characterization and Thickness Evaluation of Internal Delamination Defects in GFRP Composites |
| title_full_unstemmed | Terahertz Spectroscopic Characterization and Thickness Evaluation of Internal Delamination Defects in GFRP Composites |
| title_short | Terahertz Spectroscopic Characterization and Thickness Evaluation of Internal Delamination Defects in GFRP Composites |
| title_sort | terahertz spectroscopic characterization and thickness evaluation of internal delamination defects in gfrp composites |
| topic | Glass-fiber-reinforced polymer-matrix (GFRP) composites Terahertz time-domain spectroscopy (THz-TDS) Nondestructive testing and evaluation (NDT&E) Stationary wavelet transform (SWT) Thickness evaluation Delamination defects |
| url | https://doi.org/10.1186/s10033-022-00829-7 |
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