Interpenetrating Lattices with Tailorable Energy Absorption in Tension

Abstract

This paper introduces the chain lattice, a hierarchical porous structure comprising two interpenetrating cellular solids. One constituent toughens the material and prevents catastrophic localized failure while the other serves as a porous matrix which densifies to absorb energy during tensile loading. Through tension testing, we demonstrate 3D-printed plastic chain lattices that exhibit delocalized damage and an order of magnitude increment in strain-to-failure over the fully dense base material. These experiments validate a micromechanics-based model of tensile specific energy absorption, which we then use in a parametric study on the effects of chain geometry and matrix properties on tensile behavior. We find that ceramic chain lattices can achieve an order of magnitude improvement in tensile specific energy absorption over the fully dense material, in line with the improvement seen when forming monolithic ceramics into fiber-reinforced ceramic matrix composites. The experiments and analysis highlight the ability of the chain lattice to impart damage-tolerance to 3D-printable materials that are normally brittle and flaw-sensitive.