A
refined model able to analyze edge debonding problems in beams strengthened
with externally bonded composite laminated plates, is presented. The structural
system is viewed as composed by three different physical components: the base
beam, the adhesive layer and the bonded plate. Each component may be comprised
by one or several mathematical layers which adopts the first-order shear
deformation laminate theory. Bonding and continuity conditions between
different layers are simulated by using the interface modelling technique.
According to a fracture mechanics approach, the analysis is carried out by
evaluating the total and individual mode components of energy release rate
(ERR). Applications for typical strengthened systems, carried out by numerical
integration procedures, are proposed. The approximations introduced in the
model with respect to the adopted number of mathematical layers are analyzed
and comparisons with existent FE models are given. For the simpler two-layer
model of the structure, a closed-form solution is obtained. Finally, the effect
of different debonding modes on the overall behaviour of the structural system
is analyzed. These results show the capability and the accuracy of the proposed
approach to predict debonding failure behaviour in strengthened beams.