A helical elastic wave metasurface based on GSL

Abstract

Based on the Generalized Snell’s Law (GSL), combined with the elastic wave propagation theory in the thin plate and beam structure, a new type of elastic wave metasurface is constructed. The metasurface structure realizes the design of equal gradient of transmitted wave phase according to the difference of the length of different helical curved beams. Through this structure, the transmission wavefront of the Lamb wave in the thin plate is controlled, and acoustic phenomena such as negative refraction and asymmetric transmission are realized, which proves the accuracy of the GSL theory and the feasibility of the structure. And on this basis, the use of the design of symmetrical attachment to the metasurface solves the problem of destroying the plate structure in the traditional elastic wave metasurface, and provides an effective new idea for the elastic wave metasurface.