FEM modelling of single-core sandwich and 2-core multilayer beams containing foam aluminum core and metallic face sheets under monolithic bending

This present paper dealt with bending deformation and failure behavior of sandwich and multilayer beams composed of aluminum foam core and metallic face sheets by finite element method (FEM) and four-point bending test. Results revealed that collapse of the multilayer beams is dominated by two basic modes: indentation (ID) and core shear (CS). ID is dominated by the maximum compressive strain and CS by the maximum shear strain. The failure of the sandwich beams depends on if the face sheets show ID mode in the multilayer beams or otherwise. If a multilayer beam is dominated by ID mode, the sandwich beams with similar face sheets and same core thickness would also show ID characteristic. If a multilayer beam fails fully by CS mode, no ID characteristic would appear in similar face sheet single-core sandwiches. Beams failed by ID mode have a potential to consume more bending deformation energy than those dominated by CS mode. The dense foam can bear higher loading, which in turn, increases the ability of absorbing deformation energy for a beam. In applications of deformation energy absorption aspect, beams containing foam core and metallic face sheets should be designed to have a tendency of ID mode failure.