Dynamic Response of Nacre-Like Voronoi Brick and Mortar Structure under Explosive Load

Inspired by the brick and mortar structure of multi-scale and multi-hierarchy, a nacre-like Voronoi brick and mortar structure was created. Afterwards, the dynamic response of nacre-like Voronoi brick and mortar structure under explosive load was explored by combining 3D printing, explosion experiments, and numerical simulations. The influence of the Voronoi unit cell size and the thickness of the intralaminar soft material on the damage mode as well as the energy absorption of the structure was analyzed. Under the spherical emulsion explosive charge of 40 g, the radial cracks appeared on the front face of the nacre-like Voronoi brick and mortar structure and then spread around, while small pieces of fragments fell off the back panel. A finite element model was built and showed good agreement with the experimental results. The damage modes of nacre-like Voronoi brick and mortar structures under different explosive charges include plastic deformation, cracks occurred on the front and back face, small pieces of material falling off, damage of whole structure accompanied with shear failure at the gripper end. The horizontal normal stress of the stiff material is much larger than the vertical normal stress. Meanwhile, the shear strain in the interlaminar soft material is much larger than that in the intralaminar soft material. The specific energy absorption is 1.8−2.3 times larger in the interlaminar soft material than that in the stiff material. With the increase of the Voronoi unit cell size, the specific energy absorption of the interlaminar soft material increases by 45.6%. As the thickness of the intralaminar soft material increases, the specific energy absorption of the intralaminar soft material increases by 31.1%. This study may provide some definite reference for the design of biologically inspired structures.