Locally resonant particles enhance the stress wave attenuation in bioinspired composites

The demand for protective composites that can rapidly attenuate stress waves is high across various industrial sectors such as civil defense, armor, and ships. Drawing inspiration from dragonfly wings, this paper introduces a novel design of protective composites combining the principle of particle local resonance and bioinspired microstructures. The key findings include: (1) When the frequency of the incident wave closely matches the intrinsic frequency of the local resonance unit, maximum excitation of the local resonance mechanism occurs, and a significant amount of incident stress wave energy is converted into the mechanical energy of particles; (2) The intrinsic frequency of a local resonant unit decreases with the increase of the core particle size and density, and the soft coating thickness, but increases with the rise in the elastic modulus of the soft coatings; (3) A hybrid design with a mix of units with varying intrinsic frequencies incorporated into the composite material, can achieve effective attenuation of incident stress waves across a broad frequency range. This research provides valuable guidance for developing high-performance impact-resistant composites utilizing the principles of local resonance and bionic microstructures.