Deformation and failure of hybrid composite sandwich beams with a metal foam core under quasi-static load and low-velocity impact

The deformation and failure of hybrid composite sandwich beams with an aluminum foam core under quasi-static load and low-velocity impact are investigated. The sandwich beams comprise of two carbon fiber-reinforced plastic (CFRP) face sheets which have identical/unidentical thicknesses. The experimental results show that hybrid composite sandwich beams exhibit four active failure modes: face-sheet fracture, indentation, core shear and core shear-tension. Core shear occurs in sandwich beams with two identical face sheets, while core shear-tension develops in sandwich beams with two unidentical face sheets. An asymmetrical sandwich beam with a thicker top face sheet has superior load-carrying capability than those with a thinner top face sheet for the same total thickness of the top and bottom face sheets. For the similar failure modes of hybrid composite sandwich beams under quasi-static load and low-velocity impact, the low-velocity impact collapse load is higher than that corresponding to quasi-static collapse. The collapse loads of hybrid composite sandwich beams predicted by simple theoretical solutions are in good agreement with the experimental values.