Effect of 3D Architecture on Energy Dissipation during High-speed Particle Impact

Abstract

Ultralight mechanical metamaterials enabled by additive manufacturing (AM) have previously achieved density-normalized strength and stiffness properties that are inaccessible to monolithic materials, but the majority of this work has focused on static loading while the mechanical properties of these metamaterials under extreme dynamic loading conditions has remained largely unexplored. Here, using supersonic microparticle impact, the impact response of different 3D-printed microscale architectures are compared to each other and a non-architected mass equivalent sample to examine the effect of architecture on material impact response. This response is analyzed in a mass-normalized context and a dimensionless context analogous to (spatially confined) planetary impact. Ultra high-speed imaging and post-impact scanning electron microscopy reveal qualitative differences in the energy dissipation mechanisms present between impacts on architected and bulk materials. Additional uniaxial compression experiments on equivalent architected samples help separate the energy dissipation components during impact. This investigation could lead to improvements in the design process of lightweight materials for energy mitigation applications such as armor and protective coatings.