Failure of sandwich beams consisting of alumina face sheet and aluminum foam core in bending

Applications of sandwich structures, comprising alumina face sheets and aluminum foam core, depend critically on their mechanical performance. Four point bend tests are performed on sandwich beams with varying geometries to identify competing failure modes, such as core indentation, face sheet cracking and core shear. Analytical formulae for the identified failure modes are obtained. A failure mode map was constructed based on the analytical calculations in the non-dimensional parameters of beam geometry for a given face sheet to core strength ratio. The tested geometries are simulated using a finite element program: the beam stiffness and the failure load calculations were found to be in good agreement with the experimental and analytical results within experimental scatter.