Experimental and numerical studies on adhesively bonded CFRP laminates with closed debonds

In this paper, experimental and numerical buckling studies of adhesively bonded carbon/epoxy laminates with closed debonds are investigated. To know the effect of debonds on the load bearing capability of bonded composite laminates, two sets of studies are attempted. First, the carbon fibre reinforced (CFRP) laminates are fabricated and adhesively bonded together without any artificial debonds, secondly the closed artificial debonds of desired sizes are introduced. Studies are carried out to analyze the effect of these debonds on load bearing capacity. For the experimental studies, quasi-isotropic CFRP specimens are realized with and without artificial debonds and the buckling loads are obtained from the experiment with clamped and free boundary conditions at the loading and the non-loading edges respectively. The specimens are found to exhibit a plate-column mode of buckling. Commercially available finite element package, MSC/NASTRAN has been used for numerical analysis. The experimental and numerical loads are compared and it reveals that close correlation exits between them. From the numerical analysis, it is observed that buckling load decreases when the debond size increases.