Phononic crystals are composites with architected microstructure that exhibit superior shock mitigation properties which cannot be achieved through natural materials. In this study, the capability provided by layered phononic crystals for protection of structures subjected to near-contact detonation is investigated. To evaluate the protective performance of the layered composite, finite element simulation of a reinforced concrete (RC) column, with a layered composite attached to its surface, subjected to near-contact detonation is performed. As a reference case, the same RC column under the same near-contact detonation, without the layered composite, is also studied. Contours of damage and residual load carrying capacity of the RC column are analyzed for both cases. It is observed that due to optimized band-gap in the composite, high frequency components of the shock wave are filtered, while the low frequency components of the shock front are highly scattered. Therefore, the intense shock front with large peak overpressure and short duration gets dispersed and transforms into a wave with a longer duration and lower peak overpressure. Comparing the damage pattern in the protected RC column with the bare column, high level of protection provided by the layered composite is demonstrated. This study provides insight on how stress waves can be controlled through microstructural design of phononic crystals through topology optimization to achieve a desired dynamic and structural response.

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