Debonding in foam-core sandwich panels

The strain energy release rate is used to give a criterion for debonding in structural sandwich beams with isotropic faces and a foam core. The critical strain energy release rate of the interface is measured on double-shear specimens and the results of the debonding analysis are compared with experiments on sandwich beams with aluminium faces and foamed polyurethane cores. The analysis describes debonding failure well. Comparison of the load for bebonding with that for other failure modes shows that debonding occurs only if relatively large cracks exist at the interface between the face and the core.