Parametric Study of FRP Plate Debonding Using Global Energy Balance

Fiber-reinforced polymer (FRP) plate debonding is commonly caused by the fracturing of concrete, but few studies of fracture debonding models exist, from which the failure load of the concrete cover layer can be evaluated. This paper presents a parametric study for plate end debonding using the global energy balance approach (GEBA), which has been proposed recently for determining the structure-debonding load. GEBA determines the debonding load using moment-curvature (M-) models, and can thus be used to determine how debonding is affected by the beam's flexural design. This paper presents parametric results using debonding contours on plots of moment capacity against the plate curtailment locations, and shows that beams with the same depth-to-fracture energy ratio give virtually the same debonding contour. This helps to generalize debonding determination for beams with different depths, and can be conveniently used for design. The parametric study lays a foundation for the application of fracture mechanics in FRP-plate retrofitting design using conventional M- models to cover a wide range of flexural retrofitting situations.