Damping properties and dynamic responses of metaconcrete beam structures subjected to transverse loading

Metaconcrete consisting of engineered resonant aggregates has been adopted to mitigate wave propagation and attenuate dynamic response due to its wave filtering characteristics. Resonant aggregates made of solid cores coated with a relatively soft material can be used to achieve designable attenuation performance. So far, the damping properties of structures made of metaconcrete have not been investigated. Moreover, the current literatures that studying the wave filtering effect of metaconcrete structure concentrate on the 1D stress wave attenuation in the axial direction of the structural members. The dynamic response of metaconcrete structure subjected to transverse impulsive loading is not well studied yet. Therefore, this study investigated the damping property and dynamic response of cementitious metaconcrete with resonant aggregates made of rubber-coated steel balls (RCSB) subjected to transverse impulsive loads. A total of nine beam specimens were prepared, made of plain mortar, mortar with non-resonant inclusions and metaconcrete with various volume fractions of RCSBs (i.e., 9.2%, 18.4% and 22.9%) and different sizes of RCSBs (i.e., 22 mm, 18 mm and 15 mm). Two boundary conditions (i.e., cantilevered and clamped support) were adopted in the tests. The influence of periodic and non-periodic RCSB distributions was also analysed. The effectiveness of metaconcrete on the response attenuation subjected to different transverse impulsive loading intensities was examined. Furthermore, the bandgap characteristics obtained from the experiment were compared with the numerical prediction using COMSOL Multiphysics to verify the existence of bandgap in metaconcrete beam under dynamic transverse loading.