Time domain analysis of locally resonant elastic metamaterials under impact

The microstructure of a material can be engineered to achieve unique properties not found in nature. Microstructured materials, also known as metamaterials (MMs), can exhibit properties utilizing local resonance and dynamics of their heterogeneous microstructure that are activated below the traditional Bragg limit. In this study, the linear dynamic response of a low-frequency resonant ceramic MM slab is analyzed using the Finite Element Method (FEM) in the time domain. The MM is compared to monolithic slabs and other microstructured designs in terms of stress wave mitigation, peak load retardation, and energy transfer. Simulations are conducted using various boundary conditions and domain sizes to evaluate their influence on the performance. Potential graded slab designs and material damping effects are also discussed and are both shown to reduce the energy transmitted from the impact surface to the opposing surface significantly. The results showed that the MM slabs had superior performance in reducing the peak stress wave and reducing the transfer of energy. This study demonstrates that resonant ceramic MMs are a promising material design with unique and tunable properties that can be used for stress wave mitigation and structural protection applications.