Structural Engineering and Mechanics

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Experimental and numerical disbond localization analyses of a notched plate repaired with a CFRP patch

  • Abderahmane, Sahli (Laboratoire Mecanique Physique des Materiaux (LMPM), Department of Mechanical Engineering, University of Sidi Bel Abbes) ;
  • Mokhtar, Bouziane M. (Laboratoire Mecanique Physique des Materiaux (LMPM), Department of Mechanical Engineering, University of Sidi Bel Abbes) ;
  • Smail, Benbarek (Laboratoire Mecanique Physique des Materiaux (LMPM), Department of Mechanical Engineering, University of Sidi Bel Abbes) ;
  • Wayne, Steven F. (Medical Acoustic Laboratory, University of Memphis) ;
  • Zhang, Liang (Medical Acoustic Laboratory, University of Memphis) ;
  • Belabbes, Bachir Bouiadjra (Laboratoire Mecanique Physique des Materiaux (LMPM), Department of Mechanical Engineering, University of Sidi Bel Abbes) ;
  • Boualem, Serier (Laboratoire Mecanique Physique des Materiaux (LMPM), Department of Mechanical Engineering, University of Sidi Bel Abbes)
  • Received : 2016.09.14
  • Accepted : 2017.04.25
  • Published : 2017.08.10
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Abstract

Through the use of finite element analysis and acoustic emission techniques we have evaluated the interfacial failure of a carbon fiber reinforced polymer (CFRP) repair patch on a notched aluminum substrate. The repair of cracks is a very common and widely used practice in the aeronautics field to extend the life of cracked sheet metal panels. The process consists of adhesively bonding a patch that encompasses the notched site to provide additional strength, thereby increasing life and avoiding costly replacements. The mechanical strength of the bonded joint relies mainly on the bonding of the adhesive to the plate and patch stiffness. Stress concentrations at crack tips promote disbonding of the composite patch from the substrate, consequently reducing the bonded area, which makes this a critical aspect of repair effectiveness. In this paper we examine patch disbonding by calculating the influence of notch tip stress on disbond area and verify computational results with acoustic emission (AE) measurements obtained from specimens subjected to uniaxial tension. The FE results showed that disbonding first occurs between the patch and the substrate close to free edge of the patch followed by failure around the tip of the notch, both highest stress regions. Experimental results revealed that cement adhesion at the aluminum interface was the limiting factor in patch performance. The patch did not appear to strengthen the aluminum substrate when measured by stress-strain due to early stage disbonding. Analysis of the AE signals provided insight to the disbond locations and progression at the metal-adhesive interface. Crack growth from the notch in the aluminum was not observed until the stress reached a critical level, an instant before final fracture, which was unaffected by the patch due to early stage disbonding. The FE model was further utilized to study the effects of patch fiber orientation and increased adhesive strength. The model revealed that the effectiveness of patch repairs is strongly dependent upon the combined interactions of adhesive bond strength and fiber orientation.

Keywords

References

  1. Abaqus Analysis User's Guide (6.13).
  2. AEP4, Vallen Systeme, Germany.
  3. Albedah, A., Khan, S.M., Benyahia, F. and Bouiadjra, B.B. (2015), "Experimental analysis of the fatigue life of repaired cracked plate in aluminum alloy 7075 with bonded composite patch", Eng. Fract. Mech., 145, 210-220. https://doi.org/10.1016/j.engfracmech.2015.04.008
  4. Albedah, A., Khan, S.M., Benyahia, F. and Bouiadjra, B.B. (2016), "Effect of load amplitude change on the fatigue life of cracked Al plate repaired with composite patch", Int. J. Fatigue, 88, 1-9. Alcoa Inc. http://www.alcoa.com https://doi.org/10.1016/j.ijfatigue.2016.03.002
  5. ASTM E647-15, Standard Test Method for Measurement of Fatigue Crack Growth Rates. Active Standard ASTM E647 $\mid$ Developed by Subcommittee: E08.06, Book of Standards Volume: 03.01.
  6. Baker, A. (1993), "Recent advances in bonded composite repair technology for metallic aircraft components", Metals and Materials Society, Warrendale, PA.
  7. Baker, A. (1995), "Bonded composite repair of metallic aircraft components-Overview of disbonding activities", AGARD, CP-550.
  8. Baker, A. (1997), "On the certification of bonded composite repairs to primary aircraft structures", Proceeding of the 11th Int Conference on Composite Materials, Vol. 1, 1-24.
  9. Baker, A., Rose, F. and Jones, R. (2003), Advanced in the Bonded Composite Repair of Metallic Aircraft Structures, Volume I and II, Elsevier.
  10. Benchiha, A. and Madani, K. (2015), "Influence of the presence of defects on the stresses shear distribution in the adhesive layer for the single-lap bonded joint", Struct. Eng. Mech., 53(5), 1017-1030. https://doi.org/10.12989/sem.2015.53.5.1017
  11. Benchiha, A., Madani, K., Touzain, S., Feaugas, X. and Ratwani, M. (2016), "Numerical analysis of the Influence of the presence of disbond region in adhesive layer on the stress intensity factors (SIF) and crack opening displacement (COD) in plates repaired with a composite patch", Steel Compos. Struct., 20(4), 951-962. https://doi.org/10.12989/scs.2016.20.4.951
  12. Benzeggagh, M.L. and Kenane, M. (1996), "Measurement of mixed-mode delamination fracture toughness of unidirectional glass/epoxy composites with mixed-mode bending apparatus", Compos. Sci. Technol., 56, 439-449. https://doi.org/10.1016/0266-3538(96)00005-X
  13. Bouiadjra, B.B., Benyahia, F., Albedah, A., Bouiadjra, B.A.B. and Khan, S.M. (2015), "Comparison between composite and metallic patches for repairing aircraft structures of aluminum alloy 7075 T6", Int. J. Fatigue, 80, 128-135 https://doi.org/10.1016/j.ijfatigue.2015.05.018
  14. Bouiadjra, B.B., Ouinas, D., Serier, B. and Benderdouche, N. (2008), "Disbond effects on bonded boron/epoxy composite repair to aluminum plates", Comput. Mater. Sci., 42(2), 220-227. https://doi.org/10.1016/j.commatsci.2007.07.008
  15. Camanho, P.P. and Davila, C.G. (2002), "Mixed-mode decohesion finite elements for the simulation of delamination in composite materials", NASA/TM-2002-211737, 1-37.
  16. Denney, J.J. (1997), "Characterization of disbonding effects on fatigue crack growth behavior in aluminum plate with bonded composite patch", Eng. Fract. Mech., 57(5), 507-525. https://doi.org/10.1016/S0013-7944(97)00050-7
  17. Elhannani, M., Madani, K., Mokhtari, M., Touzain, S., Feaugas, X. and Cohendoz, S. (2016), "A new analytical approach for optimization design of adhesively bonded single-lap joint", Struct. Eng. Mech., 59(2), 313-326. https://doi.org/10.12989/sem.2016.59.2.313
  18. Fujimoto, S.E. and Sekine, H. (2007), "Identification of crack and disbonding fronts in repaired aircraft structural panels with bonded FRP composite patches", Compos. Struct., 77(4), 533-545. https://doi.org/10.1016/j.compstruct.2005.08.005
  19. Grosse, C.U. and Ohtsu, M. (2008), Acoustic Emission Testing, Springer-Verlag Berlin Heidelberg.
  20. Gu, J.U., Yoon, H.S. and Choi, N.S. (2012), "Acoustic emission characterization of a notched aluminum plate repaired with a fiber composite patch", Compos. Part A: Appl. Sci. Manuf., 43(12), 2211-2220. https://doi.org/10.1016/j.compositesa.2012.07.018
  21. Huntsman Advanced Materials company. www.araldite2000plus.com
  22. Instron: http://www.instron.fr.
  23. Khan, S.M., Benyahia, F., Bouiadjra, B.B. and Albedah, A. (2014), "Analysis and repair of crack growth emanating from v-notch under stepped variable fatigue loading", Procedia Eng., 74, 151-156. https://doi.org/10.1016/j.proeng.2014.06.240
  24. Mohamed, B. and Bouiadjra, B.B. (2016), "Analysis of the adhesive damage for different patch shapes in bonded composite repair of corroded aluminum plate", Struct. Eng. Mech., 59(1), 123-132. https://doi.org/10.12989/sem.2016.59.1.123
  25. Mohammed, S.M.A.K. (2015), "Bonded composite patch repair of aluminium plates under fatigue loading", PhD Tthesis, King Saudi University, Saudi Arabia. Riyadh.
  26. Nano 30, Physical Acoustics, Inc., Princeton, NJ, USA.
  27. Non Destructive Testing (NDT) center, https://www.nde-ed.org
  28. Ohtsu, M. (2015), Acoustic Emission and Related Non-destructive Evaluation Techniques in the Fracture Mechanics of Concrete: Fundamentals and Applications, Woodhead Publishing.
  29. Okafor, A.C., Singh, N. and Singh, N. (2007), "Acoustic emission detection and prediction of fatigue crack propagation in composite patch repaires using neural networks", AIP Conference Proceedings, Vol. 894, No. 1, 1532-1539.
  30. Ouinas, D., Bachir Bouiadjra, B., Himouri, S. and Benderdouche, N. (2012), "Progressive edge cracked aluminium plate repaired with adhesively bonded composite patch under full width disband", Compos. Part B: Eng., 43(2), 805-811. https://doi.org/10.1016/j.compositesb.2011.08.022
  31. SOL Inc. (2013), http://www.comsol.com
  32. Vallen system GmbH (2009), Acoustic emission systeme AMSY - 5 system description, Vallen Systeme GmbH.
  33. Wegman, R.F. (1989), Surface Preparation Techniques for Adhesive Bonding, Reprint Edition, Text Book.
  34. Young, A., Rooke, D.P. and Cartwright, D.J. (1989), "Numerical study of balanced patch repairs to cracked sheets", Aeronaut. J., 93, 327-334.