A Mechanical Model for Elastic Wave Propagation in NacreLike Materials With BrickandMortar Microstructures

Abstract

Many biological materials have outstanding properties unparalleled by artificial materials because of their periodic and/or hierarchical structures. In this paper, the longitudinal elastic wave propagation in nacrelike materials with brickandmortar microstructures has been studied theoretically by taking the different deformation mechanisms into account. A viscoelastic model in relation to the sacrificial bond behavior for the organic matrix has been developed. The shearlag model is adopted to simulate the deformation of the brickmortar structure. Complex band structures have been analyzed and the mechanical model has been validated by finite element method. Results have shown that bandgaps with lower edge close to vanishing frequency may arise in such bioinspired periodic structures and attenuated propagation of elastic waves may be dominant in the range of higher frequencies. It may cast light on the dynamic strengthening mechanisms in nacrelike materials and provide a scientific basis for the design of bioinspired metamaterials with lowfrequency bandgaps.