Ultrasonic technique for damage detection in composite laminates with an embedded FBG sensor

P.M. Lam, K.T. Lau, Hwa Yaw Tam, H.Y. Ling

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review


Real-time structural health monitoring of composite structures with ultrasonic technique is presented in this paper. Ultrasonic Lamb wave, which is generated by a piezoelectric actuator, can propagate into a composite laminate. When delamination is developed inside the composite laminate, the propagation characteristics of the Lamb waves are altered. Delamination information can then be obtained from the signal received by an embedded fiber Bragg grating (FBG) sensor. A laser source is used in the signal acquisition unit because it enables a higher sensitivity of the system when compared to a broadband light source. In this study, glass fiber-reinforced epoxy composite (GF/EP) laminates with artificial delamination at different layers are fabricated. FBG sensors are embedded into the GF/EP laminates for the detection of ultrasonic Lamb wave. The velocity of Lamb wave in the GF/EP laminate is predicted and compared with experimental result. The waveforms of received signals change due to different sizes of the delamination region and the trend of the change of acquired signals with the growth of delamination size are examined.
Original languageEnglish
Title of host publicationProceedings of the 3rd International Conference on Structural Health Monitoring of Intelligent Infrastructure (SHMII-3), Vancouver, 13-16 November 2007
Number of pages7
Publication statusPublished - 2007
EventInternational Conference on Structural Health Monitoring of Intelligent Infrastructure [SHMII] -
Duration: 1 Jan 2007 → …


ConferenceInternational Conference on Structural Health Monitoring of Intelligent Infrastructure [SHMII]
Period1/01/07 → …


  • Bragg grating sensors
  • Waves

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