The quantitative evaluation of the size of interface delamination in a glass/ epoxy (GFRP) composite T-joint is discussed here. An expression was derived to estimate the size of interface delamination from Time-of-Flight and group velocities of the fundamental anti-symmetric Lamb mode, A o. Numerical simulations were carried out on [02/90 2]s GFRP T-joint with different size of interface delaminations and validated with air-coupled ultrasonic experiments. The proposed methodology requires a baseline signal from a healthy region. Supplementary equations were presented to determine the error induced in the estimation of size of the interface delamination, due to mis-alignment during data collection.
Allyne, D.N. and Cawley, P.1992. ‘‘The Interaction of Lamb Waves with Defects,’’IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 39:381-397.
2.
ANSYS Inc.2007. Users Manual (2007), ANSYS R 11, Ansys Inc, Canonsburg, PA, USA.
3.
Bhardwaj, M.C.2001. ‘‘Non-Contact Ultrasound - The Final Frontier in Non-destructive Analysis,’’ In: Biderman, A. (ed.), Encyclopedia of Smart Materials, In;John Wiley & Sons, New York .
4.
Castaings, M., Cawley, P., Farlow, R. and Hayward, G.1998. ‘‘Single Sided Inspection of Composite Materials Using Air Coupled Ultrasound,’’J. Nondestruct. Eval., 17:37-45.
5.
Castaings, M. and Hosten, B.1998. ‘‘The Use of Electrostatic, Ultrasonic, Air-coupled Transducers to Generate and Receive Lamb Waves in Anisotropic, Viscoelastic Plates,’’ Ultrasonics, 36:361-365.
6.
Gibson, R.F.1994. Principles of Composite Materials Mechanics, McGraw Hill International Edition, Singapore.
7.
Guo, N. and Cawley, P.1993. ‘‘Lamb Waves for NDE of Composite Laminates,’’ In: Thompson, D.O. and Chimenti, D.E. (eds), Review of Progress in Quantitative Non-Destructive Evaluation, Vol. 11, pp. 1443-1450, Plenum, New York.
8.
Hayashi, T. and Kawashima, K.2002. ‘‘Multiple Reflections of Lamb Waves at a Delamination,’’ Ultrasonics, 40:193-197.
9.
Hutchins, D.A., Wright, W.M.D., Hayward, G. and Gachagan, A.1994. ‘‘Air-coupled Piezoelectric Detection of Laser-generated Ultrasound,’’IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 41:796-805.
10.
Imperial College.2003. Disperse Version 2.0.16b, Imperial College, London, UK.
11.
Islam, A.S. and Craig, K.C.1994. ‘‘Damage Detection in Composite Structures Using Piezoelectric Materials,’’ Smart Mater. Struct., 3:318-328.
12.
Jiang, Y., Leung, C.K.Y., Mandy, Ng, Motavalli, M., Feltrin, G. and Gsell, D.2009. ‘‘Delamination Detection in an I-Section Glass Fiber-reinforced Plastic Beam with an Optical Fiber-based Stress Wave Method,’’Smart Mater. Struct., 18:065003.
13.
Kesavan, A., Deivasigamani, M., John, S. and Herszberg, I.2006. ‘‘Damage Detection in T-Joint Composite Structures,’’ Compos. Struct., 75:313-320.
14.
Kessler, S.S., Spearing, S.M. and Atalla, M.J.2002. ‘‘In-Situ Damage Detection of Composite Structures Using Lamb Wave Methods,’’ In: Balageas, D. (ed.), Proceedings of the 1st European Workshop on Structural Health Monitoring, 10-12 July, Paris, France, pp. 374-381.
15.
Lee, B.C. and Staszewski, W.L.2007. ‘‘Lamb Wave Propagation Modelling of Damage Detection: I. Two-Dimensional Analysis,’’ Smart Mater. Struct., 16:249-259.
16.
Ramadas, C., Krishnan, Balasubramaniam, Joshi, M. and Krishnamurthy, C.V.2009. ‘‘Interaction of Primary Anti-Symmetric Lamb Mode with Symmetric Delaminations: Numerical and Experimental Studied,’’Smart Mater. Struct., 18:085011.
17.
Ramadas, C., Padiyar, Janardhan, Krishnan, Balasubramaniam, Makarand, Joshi and Krishnamurhty, C.V.2010. ‘‘Delamination Size Detection Using Time of Flight of Anti-Symmetric (Ao) and Mode Converted Ao Mode of Guided Lamb Waves,’’J. Intel. Mater. Syst. Struct., 21:817-825.
18.
Tan, K.S., Guo, N., Wong, B.S. and Tiu, C.G.1995. ‘‘Experimental Evaluation of Delaminations in Composite Plates by the Use of Lamb Waves,’’ Compos. Sci. Technol., 55:77-84.
19.
Toyama, N., Noda, J. and Okabe, T.2003. ‘‘Quantitative Damage Detection in Cross-Ply Laminates Using Lamb Wave Method,’’ Compos. Sci. Technol., 63:1473-1479.
20.
Toyama, N. and Takatsubo, J.2004. ‘‘Lamb Wave Method for Quick Inspection of Impact-induced Delamination in Composite Laminates,’’ Compos. Sci. Techol., 64:1293-1300.
21.
Wang, C.S. and Chang, F.K.1999. ‘‘Built-in Diagnostics for Impact Damage Identification of Composite Structures,’’ In: Chang, F.K. (ed.), Structural Health Monitoring, 2nd edn, pp. 612-621, Technomic, Lancaster.
