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Laser Ultrasonic Imaging Based on Synthetic Aperture Focusing Technique Algorithm

Authors: Sundara Subramanian Karuppasamy, Che Hua Yang

Abstract:

In this work, the laser ultrasound technique has been used for analyzing and imaging the inner defects in metal blocks. To detect the defects in blocks, traditionally the researchers used piezoelectric transducers for the generation and reception of ultrasonic signals. These transducers can be configured into the sparse and phased array. But these two configurations have their drawbacks including the requirement of many transducers, time-consuming calculations, limited bandwidth, and provide confined image resolution. Here, we focus on the non-contact method for generating and receiving the ultrasound to examine the inner defects in aluminum blocks. A Q-switched pulsed laser has been used for the generation and the reception is done by using Laser Doppler Vibrometer (LDV). Based on the Doppler effect, LDV provides a rapid and high spatial resolution way for sensing ultrasonic waves. From the LDV, a series of scanning points are selected which serves as the phased array elements. The side-drilled hole of 10 mm diameter with a depth of 25 mm has been introduced and the defect is interrogated by the linear array of scanning points obtained from the LDV. With the aid of the Synthetic Aperture Focusing Technique (SAFT) algorithm, based on the time-shifting principle the inspected images are generated from the A-scan data acquired from the 1-D linear phased array elements. Thus the defect can be precisely detected with good resolution.

Keywords: Nondestructive Testing, Ultrasonic Imaging, laser ultrasonics, linear phased array, synthetic aperture focusing technique

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[1] Kahandawa, Gayan C., et al. "Use of FBG sensors for SHM in aerospace structures." Photonic Sensors 2.3 (2012): 203-214.
[2] Doctor, Steven R. "Nuclear power plant NDE challenges—past, present, and future." AIP Conference Proceedings. Vol. 894. No. 1. American Institute of Physics, 2007.
[3] Song, Gangbing, Chuji Wang, and Bo Wang. "Structural health monitoring (SHM) of civil structures." (2017): 789.
[4] Ludwig, Reinhold, and Dino Roberti. "A nondestructive ultrasonic imaging system for detection of flaws in metal blocks." IEEE transactions on instrumentation and measurement 38.1 (1989): 113-118.
[5] Hu, Hongjie, et al. "Stretchable ultrasonic transducer arrays for three-dimensional imaging on complex surfaces." Science advances 4.3 (2018): eaar3979.
[6] Wilcox, Paul D., Caroline Holmes, and Bruce W. Drinkwater. "Advanced reflector characterization with ultrasonic phased arrays in NDE applications." IEEE transactions on ultrasonics, ferroelectrics, and frequency control 54.8 (2007): 1541-1550.
[7] Michaels, Jennifer E. "Detection, localization and characterization of damage in plates with an in situ array of spatially distributed ultrasonic sensors." Smart Materials and Structures 17.3 (2008): 035035.
[8] Hall, James S., and Jennifer E. Michaels. "Multipath ultrasonic guided wave imaging in complex structures." Structural Health Monitoring 14.4 (2015): 345-358.
[9] Zhong, Yongteng, Shenfang Yuan, and Lei Qiu. "Multi-impact source localisation on aircraft composite structure using uniform linear PZT sensors array." Structure and Infrastructure Engineering 11.3 (2015): 310-320.
[10] Wooh, Shi-Chang, and Yijun Shi. "A simulation study of the beam steering characteristics for linear phased arrays." Journal of nondestructive evaluation 18.2 (1999): 39-57.
[11] Liu, Zenghua, et al. "Damage localization in aluminum plate with compact rectangular phased piezoelectric transducer array." Mechanical Systems and Signal Processing 70 (2016): 625-636.
[12] Li, Fucai, Haikuo Peng, and Guang Meng. "Quantitative damage image construction in plate structures using a circular PZT array and lamb waves." Sensors and Actuators A: Physical 214 (2014): 66-73.
[13] Yu, L., and Z. Tian. "Phased array techniques for damage detection in aerospace structures." Structural Health Monitoring (SHM) in Aerospace Structures. Woodhead Publishing, 2016. 285-306.
[14] Chen, Xuanzhen, et al. "Flow and fracture behavior of aluminum alloy 6082-T6 at different tensile strain rates and triaxialities." PloS one 12.7 (2017): e0181983.
[15] SHEN, Zuyan, Xiaonong GUO, and Yuanqi LI. "State-of-the-arts of research on aluminum alloy structures (J)." Journal of Building Structures 28.6 (2007): 100-109.
[16] Noroy, Marie‐Hélène, Daniel Royer, and Mathias Fink. "The laser‐generated ultrasonic phased array: Analysis and experiments." The Journal of the Acoustical Society of America 94.4 (1993): 1934-1943.
[17] Liu, Zenghua, et al. "Full non-contact laser-based Lamb waves phased array inspection of aluminum plate." Journal of Visualization 21.5 (2018): 751-761.
[18] Doctor, S. R., T. E. Hall, and L. D. Reid. "SAFT—the evolution of a signal processing technology for ultrasonic testing." NDT international 19.3 (1986): 163-167.
[19] Stepinski, Tadeusz, and Fredrik Lingvall. "Synthetic aperture focusing techniques for ultrasonic imaging of solid objects." 8th European Conference on Synthetic Aperture Radar. VDE, 2010.
[20] Carcreff, Ewen, and Dominique Braconnier. "Comparison of conventional technique and migration approach for total focusing." Physics Procedia 70 (2015): 566-569.
[21] Carcreff, Ewen, Gavin Dao, and Dominique Braconnier. "Fast total focusing method for ultrasonic imaging." AIP Conference Proceedings. Vol. 1706. No. 1. AIP Publishing LLC, 2016.