Quasi-static and low-velocity impact behaviors of steel-aluminum foam sandwich beams

One of the most popular protective techniques to resist impact loading is using sandwich structures. The metal sandwich structures (metal faces and aluminum foam core) have garnered significant attention in previous studies. Although the failure of the sandwich beam is highly dependent on its core properties, little attention has been paid to the effect of aluminum foam density on the impact behaviors of metal sandwich beams. The present article investigates the quasi-static and low-velocity impact behaviors of steel-aluminum foam sandwich beams with different core densities (0.25–0.85 g/cm³) and thicknesses (10–20 mm). The loading responses of metal sandwich beams under impact loading are generally similar to those under quasi-static loading, but the impact loading leads to a much higher peak load. Increasing the core density not only changes the critical failure mode from core shear to face yield but also significantly improves impact resistance. The failure map using a modified Gibson's model is constructed and indicates that the core density has a more important influence on the failure mode of metal sandwich beams compared with the dimensional design.