Broadband elastic metamaterial with single negativity by mimicking lattice systems. (January 2015)

• Record Type: Journal Article
• Authors: Liu, Yongquan; Su, Xianyue; Sun, C.T.
• Is Part Of: Journal of the mechanics and physics of solids. Volume 74(2015:Jan.)
• Page Start: 158
• Page End: 174
• Publication Date: 2015-01
• Subjects: Elastic metamaterial -- Dispersion curve -- Band gap -- Lattice system -- Wave propagation; Mechanics, Applied -- Periodicals; Solids -- Periodicals; Mechanics -- Periodicals; Mécanique appliquée -- Périodiques; Solides -- Périodiques; Mechanics, Applied; Solids; Periodicals; 531.05
• DOI: 10.1016/j.jmps.2014.09.011
• Languages: English
• ISSNs: 0022-5096

Abstract

Abstract: The narrow bandwidth is a significant limitation of elastic metamaterials for practical engineering applications. In this paper, a broadband elastic metamaterial with single negativity (negative mass density or Young's modulus) is proposed by mimicking lattice systems. It has two stop bands and the bandwidth of the second one is infinite theoretically. The effect of the relevant parameters on band gaps is discussed. A continuum model is proposed and the selection of materials is discussed in detail. It shows that continuum metamaterials can be described accurately by using the lattice model, and the second stopband can be ultra-broad but not infinite. This discrepancy is investigated and a method is provided to calculate the upper limit of the second stopband for a continuum metamaterial. As a verification, the proposed metamaterial is used for wave mitigation over broadband frequency ranges. Moreover, the present method is extended to design 2D anisotropic elastic metamaterials, and a device to control the direction of elastic wave transmission is proposed as an example.