Dynamic Response of Metaconcrete Beam Under Blast Load

Abstract

A number of recent studies have demonstrated numerically and experimentally that metaconcrete made of engineered aggregates can mitigate the propagation of stress waves induced by impulsive load. The energy imparted into the metaconcrete structure from impulsive load can be absorbed by engineered aggregates because of the local vibration of heavy cores. The previous studies considered simple 1D metaconcrete bar structure to investigate its effectiveness on mitigating stress wave propagations. The performance of structural components made of metaconcrete under impulsive load has not been investigated yet. In this study, 3D meso-scale models of three typical beams, namely, normal concrete (NC) beam, normal metaconcrete (NMC) beam composed of normal engineered aggregates (NEA) and enhanced metaconcrete (EMC) beam composed of enhanced engineered aggregates (EEA) are generated to investigate the responses of beam structure subjected to impulsive loading. The engineered aggregates NEA and EEA are designed via the software COMSOL to have the bandgaps coincident with the primary frequencies of stress wave generated in NC beam by the considered impulsive loads. Dynamic responses of three beams subjected to near-field blast loads with different scaled distances are studied via the software LS-DYNA. It is found that the EMC beam experiences less compressive and spalling damage than NC and NMC beams subjected to near-field explosion with the scaled distance of 0.15[Formula: see text]m/kg[Formula: see text]. Under blast loading from larger scaled distance explosions, the EMC beam experiences less severe flexural and flexural-shear damage than NC and NMC beams. It can be concluded that the EMC beam demonstrates better blast-resistance performance than NC and NMC beams.