Digital shearography is widely used as a nondestructive inspection method in detection of subsurface defects and strain measurement in experimental mechanics. In addition, full field measurement and low vibration isolation requirements cause to higher application of this method in quality control applications. In this paper, the application of digital shearography in inspection of metallic samples has been studied. The subsurface defects of aluminum samples have been investigated by using a proper setup of digital shearography. The thickness of samples is 3mm and 5mm and the shear size in experiments is equal to 4mm. The samples are irradiated by a 660nm diode laser and recorded shearograms before and after thermal load have been analyzed by means of appropriate software. The results showed that, the diameter to depth ratio of defects employs important role in detectability of subsurface defects. By using this method, the minimum detectable diameter of defect is 2.5 times of its depth.
Xie, H.M., Kishimoto, S., Asundi. A., 2000, “In-plane deformation measurement using the atomic force microscope moire method”, Nanotechnology, 11(1), 24–9.
Allgaier, M., Ness, S., McIntire, P., Moore, P., 1993, "Nondestructive testing handbook: Visual and optical testing", ASNT, vol. 8.
Hung, Y.Y., 1982, “Shearography: a new optical method for strain measurement and non-destructive testing”, Opt. Eng., 21,391–5.
Steinchen, W., Yang, L., 2003, "Digital Shearography – Theory and Application of Digital Speckle Pattern Shearing Interferometry", SPIE Press, Bellingham, Washington, USA.
Schuth, M., Vossing, F. Yang, L., 2010, “Shearographic NDT-Measuring Systems in Theory and Application (Endoscope for Nondestructive Test)”, 2nd International Symposium on NDT in Aerospace.
Francis, D., Tatam, R.P., Groves, R.M., 2010, “Shearography technology and applications: a review”, Meas. Sci. Tech., 21, 1-29.
Newman J.W., 2008, “Aerospace NDT with advanced laser shearography”, Proceedings of the seventeenth world conference on nondestructive testing, Shanghai, China, 25–8.
Groves, R.M., James, S.W., Tatam, R.P., 2001, “Full surface strain measurement using shearography”, Proc. SPIE 4448, 142–52.
Nelson, D.V., “Residual Stress Determination by Hole Drilling Combined with Optical Methods”, Exp. Mech. 50, 145–58, 2010.
Groves, R.M., James, S.W, Tatam, R.P., 2004, “Shape and slope measurement by source displacement in shearography”, Opt. Lasers Eng., 41, 621–34.
Zastavnik, F., Pyl, L., Gu, J., Sol, H., Kersemans, M., Van Paepegem, W., 2014, “Comparison of shearography to scanning laser vibrometry as methods for local stiffness identification of beams strain”, 50, 82–94.
Liu, Z., Gao, J., Xie, H., Wallace, Ph., 2011, “NDT capability of digital shearography for different materials”, Optics and Lasers in Engineering, 49, 1462–1469.
Chehrghani,A. , Fotovat Eskandari,F. , Hallajan,M. , Torkamani,M. J. and Nabavi,S. H. (2018). Inspection of metallic samples defects in nondestructive testing by laser shearography with thermal loading. NDT Technology, 2(2), 19-25.
MLA
Chehrghani,A. , , Fotovat Eskandari,F. , , Hallajan,M. , , Torkamani,M. J. , and Nabavi,S. H. . "Inspection of metallic samples defects in nondestructive testing by laser shearography with thermal loading", NDT Technology, 2, 2, 2018, 19-25.
HARVARD
Chehrghani A., Fotovat Eskandari F., Hallajan M., Torkamani M. J., Nabavi S. H. (2018). 'Inspection of metallic samples defects in nondestructive testing by laser shearography with thermal loading', NDT Technology, 2(2), pp. 19-25.
CHICAGO
A. Chehrghani, F. Fotovat Eskandari, M. Hallajan, M. J. Torkamani and S. H. Nabavi, "Inspection of metallic samples defects in nondestructive testing by laser shearography with thermal loading," NDT Technology, 2 2 (2018): 19-25,
VANCOUVER
Chehrghani A., Fotovat Eskandari F., Hallajan M., Torkamani M. J., Nabavi S. H. Inspection of metallic samples defects in nondestructive testing by laser shearography with thermal loading. NDT Technology, 2018; 2(2): 19-25.
