Influence of Bandgap on the Response of Periodic Metaconcrete Rod Structure under Blast Load

Abstract

A metamaterial is an engineered material made by embedding engineered cores (heavy cores coated with a soft coating) into a matrix, which generates bandgaps such that stress waves with frequencies falling into the bandgaps can be mitigated. Metaconcrete made by embedding engineered aggregates into a mortar matrix can be used to attenuate stress waves generated by blast loads. This study presents a method for determining the metaconcrete bandgaps and designing a metaconcrete unit cell by using commercially available software to achieve the desired bandgaps. The dispersion relation of metaconcrete unit cells was investigated. With the designed configuration, the performance of metaconcrete rod structures under blast load was studied by using a software simulation. The results demonstrated the effectiveness of the designed unit cell with the selected soft coating and heavy core in mitigating blast-induced elastic and nonlinear inelastic stress-wave propagation. The responses of metaconcrete rod structures with one type of unit cell and grouped two types of unit cells with multiple bandgaps subjected to blast load were also studied. The results show that the grouped unit cells with multiple bandgaps led to better performance in wave mitigation than only one type of unit cell in the example metaconcrete rod structure.