Abnormal transmission of flexural wave based on composite thickness beam

In order to achieve abnormal deflection, focusing, and Bessel beam functions of transmitted waves within a specific frequency, in this paper, a nonresonant single-phase plate with a combined thickness beam is proposed for planar flexural waves . The transmission coefficients and phase shift of the composite thickness beam are calculated using the transfer matrix method, and the theoretical calculation is validated through finite element analysis. By a novel metagrating with phase gradient variation constructed based on the generalized Snell's Law, deflection and focusing of incident curved waves can be achieved. Finite element simulations demonstrate that the proposed metagrating exhibits multifunctional transmission capability at different frequencies. This paper presents a simple and compact metagrating with multifunctional transmission capability, providing new insights into the control of bending waves.