Assessment on energy absorption of double layered and sandwich plates under ballistic impact

To study plastic deformation and energy absorption capability of monolithic, double layered steel plates and sandwich plates with steel skins and aluminum foam core, the quasi-static compressive experimental for four types aluminum foam with different density are carried out. The modified constitutive model is presented based on experimental results. The virtual tests using numerical simulation method by finite element code LS-DYNA were conducted with different impact velocities based on quasi-static experimental parameters. Energy absorption effect of projectile shape, skins thickness, core thickness and core densities on the plastic deformation and energy absorption capability of sandwich plates are discussed. It was shown that mechanics properties of aluminum foam with different density can be described accurately by modified constitutive model. For spaced type plate, the space between first layered and second layered targets have a significant impact on plastic deformation and energy capability. With the increase of impact velocity, the absorbed energy of plates first decreased from the ballistic limit to a minimum value and then increased monotonically.