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Effect of tapered-end shape of FRP sheets on stress concentration in strengthened beams

  • Belakhdar, Khalil (Departement of Civil Engineering and Hydraulics, University of Saida) ;
  • Tounsi, Abdelouahed (Laboratoire des Materiaux et Hydrologie, Universite de Sidi Bel Abbes) ;
  • Adda Bedia, El Abbes (Laboratoire des Materiaux et Hydrologie, Universite de Sidi Bel Abbes) ;
  • Redha, Yeghnem (Departement of Civil Engineering and Hydraulics, University of Saida)
  • Received : 2010.11.05
  • Accepted : 2011.07.08
  • Published : 2011.11.25

Abstract

Bonding composite materials to structural members for strengthening purpose has received a considerable attention in recent years. The major problem when using bonded FRP or steel plates to strengthen existing structures is the high interfacial stresses that may be built up near the plate ends which lead to premature failure of the structure. As a result, many researchers have developed several analytical methods to predict the interface performance of bonded repairs. In this paper, a numerical solution using finite - difference method is used to calculate the interfacial stress distribution in beams strengthened with FRP plate having a tapered ends with different thinning profiles. These latter, can significantly reduce the stress concentration. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both beam and bonded plate. Numerical results from the present analysis are presented to demonstrate the advantages of use the tapers in design of strengthened beams.

Keywords

plate bonding;FRP composite;interfacial stresses;repaired beam;design;taper

References

  1. Belakhdar, K., Tounsi, A., Benyoucef, S., Adda-Bedia E.A. and El Hassar, S. M. (2010), "On the reduction of the interfacial stresses in a repaired beam with an adhesively bonded FRP plate", Compos. Interfaces, 17(1), 1-14. https://doi.org/10.1163/092764409X12580201111467
  2. Benyoucef, S., Tounsi, A., Meftah, S.A. and Adda-Bedia, E.A. (2006), "Approximate analysis of the interfacial stress concentrations in FRP-RC hybrid beams", Compos. Interfaces, 13(7), 561-571. https://doi.org/10.1163/156855406778440758
  3. Benyoucef, S., Tounsi, A., Meftah, S.A. and Adda-Bedia, E.A.(2007), "Creep and shrinkage effect on adhesive stressesin RC beams strengthened with composite laminates", Compos. Sci. Technol., 67(6), 933-942. https://doi.org/10.1016/j.compscitech.2006.07.007
  4. Deng, J., Marcus, M.K.L. and Stuart, S.J.M. (2004), "Stress analysis of steel beams reinforced with a bonded CFRP plate", Compos. Struct., 65(2), 205-215. https://doi.org/10.1016/j.compstruct.2003.10.017
  5. Gao, B., Kim, J.K. and Leung, C.K.Y. (2006), "Optimization of tapered end design for FRP strips bonded to RC beams", Compos. Sci. Technol,66(10), 1266-1273 https://doi.org/10.1016/j.compscitech.2005.10.026
  6. Hashemi S. H., Maghsoudi A. A. and Rahgozar R. (2008), "Flexural ductility of reinforced HSC beams strengthenedwith CFRP sheets", Struct Eng Mech, 30(4).
  7. Lee H. K., Ha S. K. and Afzal M. (2008), "Finite element analysis of shear-deficient RC beams strengthened with CFRP strips/sheets", Struct. Eng. Mech, 30(2), 247-261. https://doi.org/10.1016/j.engstruct.2007.03.021
  8. Li, G. and Ghebreyesus, A. (2006), "Fast repair of damaged RC beams using UV curing FRP composites", Compos.Struct. 72(1), 105-110. https://doi.org/10.1016/j.compstruct.2004.10.020
  9. Malek, A. M., Saadatmanesh, H. and Ehsani, M. R. (1998), "Prediction of failure load of R/C beams strengthenedwith FRP plate due to stress concentration at the plate end" ACI Struct. J., 95(2), 142-152.
  10. Mo, Y.L., Tsai, S.P. and Lee, I.S. (1998), "Seismic performance behaviour of beam - column connections in pre - stressed concrete bridges", J. Mater. Struct., 31(6), 411-417. https://doi.org/10.1007/BF02480715
  11. Pesic, N. and Pilakoutas, K., (2005), "Flexural analysis and design of reinforced concrete beams with externally bonded FRP reinforcement", Mater. Struct.38(2), 183-192. https://doi.org/10.1007/BF02479343
  12. Roberts, T.M. (1989), "Approximate analysis of shear and normal stress concentrations in adhesive layer of plated RC beams", Struct. Eng., 67(12), 229-233.
  13. Seible, F., Priestley, M.J.N., Hegemier, G.A. and Innamorato, D. (1997), "Seismic retrofit of RC columns withcontinuous carbon fibre jackets", J. Comp. Constr., 1(2), 52-62. https://doi.org/10.1061/(ASCE)1090-0268(1997)1:2(52)
  14. Smith, S.T., and Teng, J.G. (2001), "Interfacial stresses in plated RC beams" Eng. Struct., 23(7), 857-871. https://doi.org/10.1016/S0141-0296(00)00090-0
  15. Stratford, T., and Cadei, J. (2006), "Elastic analysis of adhesion stresses for the design of a strengthened plate bonded to a beam" Constr. Build. Mater., 20(1-2), 34-35. https://doi.org/10.1016/j.conbuildmat.2005.06.041
  16. Tounsi, A. (2006), "Improved theoretical solution for interfacial stresses in concrete beams strengthened with FRP plate", Int. J. Solids Struct., 43(14-15), 4154-4174. https://doi.org/10.1016/j.ijsolstr.2005.03.074
  17. Tounsi, A. and Benyoucef, S. (2007), "Interfacial Stresses in Externally FRP Plated Concrete Beams", Int. J. Adhes.Adhes., 27(3), 207-215. https://doi.org/10.1016/j.ijadhadh.2006.01.009
  18. Tounsi, A., Hassaine, T. D., Benyoucef, S. and Adda-Bedia, E.A, (2009), "Interfacial stresses in FRP-plated beams: Effect of adherend shear deformation", Int. J. Adhes. Adhes. 29, 343-351. https://doi.org/10.1016/j.ijadhadh.2008.06.008
  19. Tsai, M.Y., Oplinger, D.W. and Morton, J. (1998), " Improved theoretical solutions for adhesive lap joints", Int. J. Solids Struct., 35(12), 1163-1185. https://doi.org/10.1016/S0020-7683(97)00097-8
  20. Wu H. L. and Wang Y. F. (2010), "Experimental study on reinforced high-strength concrete short columns confinedwith AFRP sheets", Steel Compos Struct, 10(6).
  21. Yang, J., Ye, J. and Niu, Z. (2007), "Interfacial shear stress in FRP-plated RC beams under symmetric loads", Cem. Concr. Compos., 29(5), 421-432. https://doi.org/10.1016/j.cemconcomp.2006.11.011
  22. Yuan, H. and Lin, Z. (2009), "Theoretical model on interface failure mechanism of reinforced concrete continuous beam strengthened by FRP", Acta Mechanica Solida Sinica, 22(2), 161-170. https://doi.org/10.1016/S0894-9166(09)60101-4
  23. Zhu Y. and Zhang Y. X. (2010), "Nonlinear finite element analyses of FRP-reinforced concrete slabs using a new layered composite plate element", Comput. Mech. 46(3), 410-430.

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