Experimental and numerical assessment of stress wave attenuation of metaconcrete rods subjected to impulsive loads

Abstract

Metaconcrete contained engineered resonant aggregates has drawn much attention in recent years as it can mitigate vibration and stress wave propagation, which can potentially be used in construction for structure protection against impulsive loads. However, no experimental study on cement-based metaconcrete has been conducted to reveal the performance on mitigation of stress waves induced by impulsive loading. In this study, the performance of concrete specimen composed of cementitious mortar and different inclusions including natural aggregates, steel balls and resonant aggregates against impulsive load were experimentally examined, in which the resonant aggregates were made of rubber-coated steel balls (RCSBs). The effect of volume fraction of engineered aggregates on the stress wave attenuation effectiveness was investigated. The effectiveness of metaconcrete with its bandgaps covering or not covering the primary dominant wave frequency (PDWF) on wave propagation mitigation was also evaluated. The results showed that specimen with the bandgap covering PDWF leads to more effective wave filtering and better performance in wave mitigation. Furthermore, the experimental results were used to calibrate a developed numerical model in finite element code LS-DYNA. With the validated numerical model, the effectiveness of metaconcrete on mitigation of wave propagation induced by different impulsive loading profiles was investigated. The results derived from this study could be applied to the design of metaconcrete with targeted bandgaps for resisting specific impulsive loadings.