The asymmetrical transmission characteristics of shear horizontal guided wave in an asymmetricalstructure

The cut-off frequency of higher modes of shear horizontal (SH) guided wave propagating in a plate depends on the thickness due to dispersive characteristic. Through numerical simulation of the first higher (SH₁) mode of SH guided wave propagation in an asymmetric structure, we have realized sound unidirectional transmission based on breaking spatial inversion symmetry. It demonstrated that when the SH₁ mode are launched into the system from the left side, it mostly converts to the fundamental mode in the defected region and attain a high transmission; on the contrary, when the waves are incident from the right side, the conversion is weak, most SH₁ mode is reflected and the transmission is low. This asymmetric system should be potentially significant in putting to good use in a variety of applications.