Modelling the FRP-concrete delamination by means of an exponential softening law

摘要

Among rehabilitation strategies, bonding of Fibre Reinforced Polymers (FRP) plates is becoming more and more popular, especially for what concerns concrete structures. The performance of the interface between FRP and concrete is one of the key factors affecting the behaviour of the strengthened structure. Up to now, closed-form analytical solutions exist only for the local bond-slip law with linear softening. The aim of the present paper is to show that analytical solutions can be achieved also assuming an exponential decaying softening law. Accordingly, the expressions for the interfacial shear stress distribution and the load-displacement response are derived for the different loading stages. A full parametric analysis of the problem has been performed, highlighting the size effect on the structural behaviour as well as the effects of the bond length, of the FRP stiffness and of the interface cohesive law. A comparison with other analytical models as well as with experimental data available in the literature concludes the paper. 【Keywords】FRP;Debonding;Shear lag models;Fracture mechanics;Cohesive models;Exponential softening;