Mechanical behaviour of FRP adhesive joints: A theoretical model

In this paper a mathematical model for studying the equilibrium problem of adhesive joints between FRP adherents is presented. In particular, double and single-lap joints, both in the case of normal and shear/flexure stresses are considered. The problem is non linear due to the cohesive constitutive law adopted for modeling the interface. On the contrary, the adherents are supposed to be indefinitely linear elastic.The possibility to uncouple the problem of shear/flexure from the extensional one, as well as disregard the mutual effects between the normal and tangential stresses acting at the joint interfaces is also assumed. As highlighted in literature, this hypothesis allows results which are sufficiently correct from a technical perspective when the mechanical characteristics of the adherents are almost the same, as supposed in the present paper. Within such a framework it is possible to trace back the examined equilibrium problems to those of simpler auxiliary structural schemes. A simple and efficient iterative procedure for solving the aforementioned problems is also proposed.