受到电子二极管整流效应的启发,对单向声传播结构展开了一系列的理论与实验研究:将超晶格结构与非线性声学材料组合构成了可实现声整流效应的声二极管结构;通过将反对称弹性结构引入到复合结构板来产生Lamb波的不对称模式转化,设计了可实现Lamb波单向传播的线性声学结构;基于声子晶体的部分禁带特性,在有限尺度声学系统中设计并实现了单向声学波导结构;设计并实现了由纯板与声栅构成的声单向传播结构,具有小尺寸与高效率的特点,且声波出射角度可调;基于声学梯度材料设计了可在极宽频带内实现不对称声传播的声学结构。
Inspired by the significant rectification effect of electric diode, the unidirectional transmission of acoustic waves is studied both theoretically and experimentally, and a series of acoustic one-way structures have been developed: an acoustic diode is designed and fabricated by coupling a superlattice with nonlinear acoustic medium, which is able to yield acoustic rectification effect; linear acoustic one-way structure supporting unidirectional transmission of Lamb waves is proposed by introducing asymmetric structure into composite plate to yield asymmetric mode conversion of Lamb waves; directional acoustic waveguide structure is designed and fabricated, which is capable of yielding unidirectional acoustic transmission in finite-sized acoustic systems; acoustic one-way structure composed of a pure plate and an acoustic grating is designed and fabricated, which takes the advantages of small size and high efficiency; by employing acoustic gradient medium, an acoustic structure is proposed to yield asymmetric acoustic transmission in a considerably broad band.