Broadband Waterborne Multiphase Pentamode Metastructure with Simultaneous Wavefront Manipulation and Energy Absorption Capabilities

Acoustic metastructures are artificial structures which can manipulate the wavefront in sub-wavelength dimensions, and previously proposed acoustic have been mostly realized with single materials. An metastructure composite structure is for underwater stealth considering both manipulation sound absorption. The unit cells of composed a metallic supporting lattice, interconnecting polymer materials mass balancing columns. With gradual modulations equivalent physical properties along horizontal direction metastructure, incident wave reflected to other directions. Meanwhile, material inside will dissipate energy due inherent damping properties. simultaneous scattering amplitude, significant improvement effect achieved. Compared single-phase Far-Field Sound Pressure Level (FFSPL) multiphase decreases by 4.82 dB within frequency range 3 kHz~30 kHz. linearized mean stress only 1/3 that it having much thicker struts more uniform distribution under same hydrostatic pressure. possesses potential applications its acceptable thickness (80 mm) low density (1100 kg/m3).