Influence of face/core interface on debond toughness of foam and balsa cored sandwich

The face/core debond fracture resistance of sandwich panels consisting of glass fiber/vinylester face sheets over a 155 kg/m(3) end-grain balsa wood core and a 200 kg/m(3) PVC foam core has been examined. The sandwich panels were prepared using a variety of resin infusion strategies with the objective of comparing face/core adhesion. The resin infusion methods include machining grooves in the core, adding a layer of continuous filament mat at the face/core interface, resin distribution medium on top of the face sheet fibers, and no infusion aid but significantly delayed gel-time by addition of cure inhibitor. The tilted sandwich debond (TSD) method is used for determination of debond fracture toughness (G(C)). It was found that the use of a continuous filament mat between the face and core provided the toughest interface, although the panels prepared using the resin cure inhibitor are almost as tough. Overall, the PVC foam core provided higher toughness than the balsa wood core.