Three-dimensional single-phase elastic metamaterial for low-frequency and broadband vibration mitigation

Abstract

Elastic metamaterials with local resonance bandgaps are promising for low-frequency vibration mitigation. However, such locally resonant metamaterials inherently possess narrow bandgap width, and are usually achieved by multi-material structures, which are difficult to fabricate, limiting their potential in engineering practice. Here, we present a class of 3D single-phase elastic metamaterials exhibiting both locally resonant and Bragg scattering bandgaps. The local resonance of the single-material structure is achieved through the structural configuration rather than the combination of multiple materials. The bandgap property and effective mass density are investigated based on the numerical simulation and theoretical models. Furthermore, by constructing a graded system, the local resonance bandgap and Bragg scattering bandgap can be overlapped to form an ultra-wide vibration attenuation frequency range. The results are verified experimentally by a sample fabricated using additive manufacturing. This study suggests a feasible approach for realizing elastic metamaterials for engineering application.