Precise method to control elastic waves by conformal mapping

作     者：Yongquan Liu Wei Liu Xianyue Su 

作者机构：LTCS and Department of Mechanics and Aerospace Engineering College of Engineering Peking University 

出 版 物：《Theoretical & Applied Mechanics Letters》 (力学快报（英文版）)

年 卷 期：2013年第3卷第2期

页      面：62-67页

学科分类：08[工学] 080102[工学-固体力学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China (90916007 and 91116008) 

主　　题：transformation method elastic waves conformal mapping Helmholtz decompositionmethod metamaterials 

摘      要：The transformation method to control waves has received widespread attention in electromagnetism and acoustics. However, this machinery is not directly applicable to the control of elastic waves, because it has been shown that the Navier＇s equation does not usually retain its form under coordinate transformation. In this letter, we prove the form invariance of the Navier＇s equation under the conformal mapping based on the Helmholtz decomposition method. The needed material parameters are provided to manipulate elastic waves. The validity of this approach is confirmed by an active stealth device which can disguise the signal source by changing its position. Experimental verifications and potential applications may be expected in nondestructive testing, structural seismic design and other fields.