Split Hopkinson bar tests on metaconcrete: modeling and numerical simulations

Abstract

The work deals with the dynamic characterization of metaconcrete, a mechanical metamaterial with locally resonant inclusions and unconventional dynamic performance. Metaconcrete can be defined as an unusual concrete in which standard aggregates are partially replaced by engineered ones made of a rigid heavy core covered by a compliant layer. From a mechanical point of view, its mitigation properties are associated to the mechanical energy trapped by the inclusions when acted upon by an elastic pulse with a frequency content close to their own resonant frequencies. So far, a discrete number of experimental investigations have been performed but none of these consider the impulsive nature of blast and impact loadings and the direction of the incoming wave with respect to the inclusion orientation in case of a brittle matrix. The results of numerical simulations considering different configurations of engineered inclusions within a single metaconcrete unit are compared in terms of stress level attained as well as internal and kinetic energy involved. Metaconcrete can bring about disruptive applications in several fields of applied sciences, but for the technology to become firmly established a synergism between computational and experimental approaches is paramount.