High-speed angular-scan pulse-echo ultrasonic propagation imager for in situ non-destructive evaluation

  • Abbas, Syed H. (Department of Aerospace Engineering, Korean Advanced Institute for Science and Technology) ;
  • Lee, Jung-Ryul (Department of Aerospace Engineering, Korean Advanced Institute for Science and Technology)
  • Received : 2017.05.20
  • Accepted : 2017.11.28
  • Published : 2018.08.25


This study examines a non-contact laser scanning-based ultrasound system, called an angular scan pulse-echo ultrasonic propagation imager (A-PE-UPI), that uses coincided laser beams for ultrasonic sensing and generation. A laser Doppler vibrometer is used for sensing, while a diode pumped solid state (DPSS) Q-switched laser is used for generation of thermoelastic waves. A high-speed raster scanning of up to 10-kHz is achieved using a galvano-motorized mirror scanner that allows for coincided sensing and for the generation beam to perform two-dimensional scanning without causing any harm to the surface under inspection. This process allows for the visualization of longitudinal wave propagation through-the-thickness. A pulse-echo ultrasonic wave propagation imaging algorithm (PE-UWPI) is used for on-the-fly damage visualization of the structure. The presented system is very effective for high-speed, localized, non-contact, and non-destructive inspection of aerospace structures. The system is tested on an aluminum honeycomb sandwich with disbonds and a carbon fiber-reinforced plastic (CFRP) honeycomb sandwich with a layer overlap. Inspection is performed at a 10-kHz scanning speed that takes 16 seconds to scan a $100{\times}100mm^2$ area with a scan interval of 0.25 mm. Finally, a comparison is presented between angular-scanning and a linear-scanning-based pulse-echo UPI system. The results show that the proposed system can successfully visualize defects in the inspected specimens.


Supported by : Ministry of Trade, Industry & Energy (MI), National Research Foundation of Korea


  1. Abetew, A.D., Hong, S.C., Lee, J.R., Baek, S. and Ihn, J.B. (2017), "Remote defect visualization of standard composite coupons using a mobile pulse-echo ultrasonic propagation imager", Adv. Compos. Mater., 26(1), 15-27.
  2. ASM Handbook (1989), Volume 17: Nondestructive Evaluation and Quality Control, ASM International.
  3. Aylward, R.P. (1999), "Advances and technologies of galvanometer-based optical scanners", In Proc. SPIE, 3787, 158-164.
  4. Bentouhami, F., Campagne, B., Cuevas, E., Drake, T., Dubois, M., Fraslin, T., Pineiro, P., Serrano, J. and Voillaume, H. (2010), "LUCIE-A flexible and powerful Laser Ultrasonic system for inspection of large CFRP components", Proceedings of the 2nd International Symposium on Laser Ultrasonics, Talence, France.
  5. Campagne, B., Voillaume, H., Gouzerh, L. and Bentouhami, F. (2013), "Laser ultrasonic developments for NDT of aeronautic composite parts", Proceedings of the 13th International Symposium on Nondestructive Characterization of Materials (NDCM-XIII), Le Mans, France.
  6. Chang, F.P., Drake, T.E., Osterkamp, M.A., Monchalin, J.P., Heon, R., Bouchard, P., Padioleau, C., Froom, D.A., Frazier, W. and Barton, J. (1993), "Laser ultrasonic inspection of honeycomb aircraft structures", Review of Progress in Quantitative NDE, 12, Plenum Press, New York, 611-616.
  7. Chia, C.C., Lee, J.R. and Shin, H.J. (2009), "Hot target inspection using a welded fibre acoustic wave piezoelectric sensor and a laser-ultrasonic mirror scanner", Measur. Sci. Technol., 20(12), 127003.
  8. Cho, S., Lee, J. and Sim, S.H. (2018), "Comparative study on displacement measurement sensors for high-speed railroad bridge", Smart Struct. Syst., 21(5), 637-652.
  9. Edwards, C., Stratoudaki, T., Dixon, S. and Palmer, S. (2001), "Laser generated ultrasound: efficiency and damage thresholds in carbon fibre reinforced composites", IEE Proceedings-Science, Measurement and Technology, 148(4), 139-142.
  10. Gholizadeh, S. (2016), "A review of non-destructive testing methods of composite materials", Procedia Struct. Integrity, 1, 50-57.
  11. Hong, S.C., Abetew, A.D., Lee, J.R. and Ihn, J.B. (2016), "Three dimensional evaluation of aluminum plates with wall-thinning by full-field pulse-echo laser ultrasound", Optics and Lasers in Engineering.
  12. Hong, S.C., Lee, J.R. and Jung-il, k. (2017), "In process quality control of F-16 brake disk using in-process through-transmission ultrasonic propagation imaging system", In Korean Society of Nondestructive Testing (KSNT), Daegu, South Korea, May.
  13. Hong, S.C., Lee, J.R., Chong, S.Y. and Park, C.Y. (2012), "Effect of Laser Pulse Fatigue on the Mechanical Characteristics of a CFRP Plate", Appl. Mech. Mater., 225, 121-126.
  14. Hutchins, D.A. (1988), Ultrasonic generation by pulsed lasers, Phys. Acoust., 18, 21-123.
  15. Koehler, B., Hentges, G. and Mueller, W. (1997), "A novel technique for advanced ultrasonic testing of concrete by using signal conditioning methods and a scanning laser vibrometer", Proceedings of the 4th International Conference on Nondestructive Testing in Civil Engineering, Liverpool, Uk.
  16. Kundu, T. (2003), Ultrasonic Nondestructive Evaluation: Engineering and Biological Material Characterization, CRC press, New York, NY, USA.
  17. Lee, J.R., Jeong, H., Ciang, C.C., Yoon, D.J. and Lee, S.S. (2010), "Application of ultrasonic wave propagation imaging method to automatic damage visualization of nuclear power plant pipeline", Nuclear Engineering and Design, 240(10), 3513-3520.
  18. Lee, J.R., Shin, H.J., Chia, C.C., Dhital, D., Yoon, D.J. and Huh, Y.H. (2011), "Long distance laser ultrasonic propagation imaging system for damage visualization", Opt. Laser. Eng., 49(12), 1361-1371.
  19. McKie, A.D. and Addison, R.C. (1994), "Practical considerations for the rapid inspection of composite materials using laserbased ultrasound", Ultrasonics, 32(5), 333-345.
  20. Saleem, M. (2017), "Study to detect bond degradation in reinforced concrete beams using ultrasonic pulse velocity test method", Struct. Eng. Mech., 64(4), 427-436.
  21. Scruby, C.B. and Drain, L.E. (1990), Laser Ultrasonics Techniques and Applications, CRC Press, New York, NY, USA.
  22. Truong, C.T., Kang, D.H., Lee, J.R. and Farrar, C.R. (2015), "Comparative study of laser Doppler vibrometer and capacitive air-coupled transducer for ultrasonic propagation imager and the new development of an efficient ultrasonic wavenumber imaging algorithm", Strain, 51(4), 332-342.
  23. Truong, T.C. and Lee, J.R. (2016), "SNR enhancement for composite application using multiple Doppler vibrometers based laser ultrasonic propagation imager", Opt. Laser. Eng., 84, 82-88.
  24. Wdowik, R., Nazarko, P. and Porzycki, J. (2015), "Application of eddy current sensor System and LDV device for ultrasonic vibrations measurements", In Mechatronics-Ideas for Industrial Application, Springer, Cham, 407-415.
  25. Yim, H.J., Park, S.J., Kim, J.H. and Kwak, H.G. (2016), "Evaluation of freezing and thawing damage of concrete using a nonlinear ultrasonic method", Smart Struct. Syst., 17(1), 45-58.
  26. Zhou, W., Li, H. and Yuan, F.G. (2016), "An anisotropic ultrasonic transducer for Lamb wave applications", Smart Struct. Syst., 17(6), 1055-1065.