三维各向异性增材制造五模材料的设计与表征

Design and characterization of a three-dimensional anisotropic additively manufactured pentamode material.

作者信息

Cushing Colby W, Kelsten Matthew J, Su Xiaoshi, Wilson Preston S, Haberman Michael R, Norris Andrew N

机构信息

Walker Department of Mechanical Engineering and Applied Research Laboratories, The University of Texas at Austin, Austin, Texas 78712, USA.

Mechanical and Aerospace Engineering, Rutgers University, Piscataway, New Jersey 08854, USA.

出版信息

J Acoust Soc Am. 2022 Jan;151(1):168. doi: 10.1121/10.0009161.

DOI:10.1121/10.0009161

PMID:35105002

Abstract

A metamaterial of particular interest for underwater applications is the three-dimensional (3D) anisotropic pentamode (PM), i.e., a structure designed to support a single longitudinal wave with a sound speed that depends on the propagation direction. The present work attempts to experimentally verify anisotropic sound speeds predicted by finite element simulations using additively manufactured anisotropic 3D PM samples made of titanium. The samples were suspended in front of a plane wave source emitting a broadband chirp in a water tank to measure time of flight for wavefronts with and without the PM present. The measurement utilizes a deconvolution method that extracts the band limited impulse response of data gathered by a scanning hydrophone in a plane of constant depth behind the samples. Supporting material takes the form of finite element simulations developed to model the response of a semi-infinite PM medium to an incident normal plane wave. A technique to extract the longitudinal PM wave speed for frequency domain simulations based on Fourier series expansions is given.

摘要

一种在水下应用中特别受关注的超材料是三维（3D）各向异性五模（PM），即一种被设计用来支持单一纵波的结构，其声速取决于传播方向。目前的工作试图通过使用由钛制成的增材制造各向异性3D PM样品，对有限元模拟预测的各向异性声速进行实验验证。将样品悬浮在水箱中一个发射宽带啁啾信号的平面波源前方，以测量有和没有PM时波前的飞行时间。该测量利用一种反卷积方法，该方法提取由扫描水听器在样品后方恒定深度平面上收集的数据的带限脉冲响应。支撑材料采用有限元模拟的形式，该模拟用于对半无限PM介质对入射法向平面波的响应进行建模。给出了一种基于傅里叶级数展开从频域模拟中提取纵向PM波速的技术。