3D intra-cellular wave dynamics in a phononic plate with ultra-wide bandgap: attenuation, resonance and mode conversion

Abstract The intra-cellular wave dynamics of a water jetted phononic plate are experimentally investigated by means high-resolution three-dimensional (3D) scanning laser Doppler vibrometry. study is focused on the vibrational behavior around ultra-wide bandgap (with relative width 0.89), as critical frequency range its functionality. Broadband excitations applied using piezoelectric transducer and both in-plane out-of-plane operational deflection shapes unit-cells analyzed with respect to mode calculated finite element (FE) simulation. Attenuation resonance symmetric antisymmetric modes validated, it shown that despite absence energy actuation, effectively excited in lattice, due conversion from co-existing modes. Supported FE modal analysis, this observation explained slight through-the-thickness asymmetry introduced during manufacturing which leads coupling different symmetry. results confirm potential such detailed 3D inspection crystals (and general acoustic metamaterials) gaining full insight about their intracellular dynamics, can also illuminate discrepancies idealized numerical models might be imperfections.