Dynamic response of CFRP-lattice sandwich structures subjected to underwater shock wave loading

Carbon fiber reinforced composites (CFRP) and porous lattice structures possess the advantages of high specific strength and outstanding energy absorption efficiency. However, the structures combining their merits for underwater explosion protection receives little attention, and the underlying mechanics are still not clear. In this work, a CFRP-lattice sandwich structure is proposed, and its responses subjected to the underwater shock wave loading is studied via the finite element code ABAQUS/Explicit. The numerical results are first validated by the existing experiments (Huang et al., 2016), and the influences of the geometrical and load factors on the deformation modes and energy absorption performances are further explored. Results shows that with the variation of the load intensity and structural configuration, the failure modes of the plates can be mainly divided into three types. The failure occurs in the middle layer of the metal porous lattice core along the thickness direction. The thickness of the back plate has a greater influence on the overall deformation of the structure than that of the front plate. When the thickness of the back plate increases, the energy absorption of the front plate increases first and then decreases under the condition of a small shock wave load. The impact resistance of composite sandwich structure is the result of the coupling of core layer and plates. The proportion of energy absorption of each layer is affected by the form of structural energy transfer. The work of this paper provides guidance for the design of underwater protective equipment.