Triply periodic minimal surfaces sandwich structures subjected to shock impact

Abstract

Triply periodic minimal surfaces are cellular structures that naturally inspired continuous non-self-intersecting surfaces similar to bone microstructure with controllable mechanical properties. In this work, sandwich composite panels constructed from four different types of TMPS unit cells and metallic facets are numerically investigated and compared to evaluate the dynamic behaviours when subjected to extreme loadings. The finite element analysis is utilised to simulate the deformation of proposed structures considering the rate-dependent properties, elastoplastic response and nonlinear contact. The Johnson–Cook material model is implemented to capture the transient responses of the four TPMS panels under high strain-rate loadings. The numerical model is validated with a two-dimensional analytical one to reveal the static and dynamic crushing behaviors. Only a quarter of the sandwich panel is simulated using shell elements thanks to the symmetry, which significantly reduces the computational cost. A series of parametric studies are conducted to demonstrate the influences of different design parameters on the blast resistances of triply periodic minimal surface composite panels. Reaction forces and critical stresses extracted from underneath protected structure are assessed for various key parameters, including triply periodic minimal surface type, thickness and number of layers. The four TPMS sandwich structures clearly demonstrate unique dynamic crushing responses, impact energy mitigation and dissipation mechanisms, which leads to enhancement of the blast resistance.