声学黑洞结构应用中的力学问题

Abstract

声学黑洞 (acoustic black hole, ABH) 效应是利用薄壁结构几何参数或者材料特性参数的梯度变化，使波在结构中的传播速度逐渐减小，理想情况下波速减小至零从而不发生反射的现象．实现声学黒洞效应的主要方法是将薄板结构的厚度按照一定规律裁剪，利用声学黑洞可以将结构中传播的波动能量聚集在特定的位置．声学黑洞对波的聚集具有宽频高效、实现方法简单灵活等特点，在薄壁结构的减振降噪、能量回收等应用中具有明显的优势．本文介绍声学黑洞效应的基本原理、相关力学问题的研究进展和有待进一步探究的问题，包括声学黑洞结构的建模与分析方法、实验研究方法及进展、声学黑洞结构中波的传播与操控，以及声学黑洞在工程应用中的相关问题． Acoustic black hole (ABH) effect utilizes the gradient variance of the structural configuration or material properties to diminish wave velocity in the structure. The wave velocity decreases to zero in an ideal scenario, resulting in zero reflection. The mainstream method to realize ABH effect is to tailor the structure thickness properly, such that energy is captured in a certain area. Great advantages and potential in applications for flexural wave manipulation in thin-walled structure result from its high efficiency, broadband characteristics and flexible implementation. We introduce basic principles of ABH effect, recent progress of related mechanical problems, and problems to be further explored. We describe the modeling and analysis method of ABH structure, the method and progress of experimental studies, manipulation and propagation of waves in ABH structures, and related issues in engineering applications of ABH structures.