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


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.


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


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