Penetration behaviour of aluminium foam sandwich plates under repeated impacts and the effects of impactor shape

Marine structures frequently suffer from repeated impact loadings, the damage cannot be neglected for the accumulation of deformation due to repeated impacts. In this paper, experimental study was employed to analyze the penetration behavior and energy dissipation of aluminum foam sandwich plates (AFSP) under repeated impacts, and the effects of impactor shape on penetration behaviour and energy absorption of AFSP were determined. Results show that, even when fracture appears on the front face, the sandwich plate still has the capacity to stand the following impacts. The penetration process of AFSP can be divided into three stages according to the damage sequence of face sheet and foam core, namely fracture of front face, compaction of foam core and penetration of back face. In these three stages, the dynamic behavior and energy dissipation of AFSP are quite different. The major failure model of the front face of AFSP under repeated impacts with wedge nose and flat nose is shear while for spherical nose the major failure model is tension. When AFSP suffers from repeated impacts with spherical nose, the energy consumed by AFSP is larger compared with those of wedge nose and flat nose, and the penetration number is the largest. © 2023 China Ship Scientific Research Center. All rights reserved.