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Title: Achieving selective interrogation and sub-wavelength resolution in thin plates with embedded metamaterial acoustic lenses

Abstract

In this study, we present an approach to ultrasonic beam-forming and high resolution identification of acoustic sources having critical implications for applications such as structural health monitoring. The proposed concept is based on the design of dynamically tailored structural elements via embedded acoustic metamaterial lenses. This approach provides a completely new alternative to conventional phased-array technology enabling the formation of steerable and collimated (or focused) ultrasonic beams by exploiting a single transducer. Numerical results show that the ultrasonic beam can be steered by simply tuning the frequency of the excitation. Also, the embedded lens can be designed to achieve sub-wavelength resolution to clustered acoustic sources, which is a typical scenario encountered in incipient structural damage.

Authors:
;  [1]
  1. Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
Publication Date:
OSTI Identifier:
22314577
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BEAMS; DAMAGE; DESIGN; EXCITATION; LENSES; MONITORING; RESOLUTION; TRANSDUCERS; TUNING; WAVELENGTHS

Citation Formats

Semperlotti, F., E-mail: fsemperl@nd.edu, and Zhu, H.. Achieving selective interrogation and sub-wavelength resolution in thin plates with embedded metamaterial acoustic lenses. United States: N. p., 2014. Web. doi:10.1063/1.4892017.
Semperlotti, F., E-mail: fsemperl@nd.edu, & Zhu, H.. Achieving selective interrogation and sub-wavelength resolution in thin plates with embedded metamaterial acoustic lenses. United States. doi:10.1063/1.4892017.
Semperlotti, F., E-mail: fsemperl@nd.edu, and Zhu, H.. Thu . "Achieving selective interrogation and sub-wavelength resolution in thin plates with embedded metamaterial acoustic lenses". United States. doi:10.1063/1.4892017.
@article{osti_22314577,
title = {Achieving selective interrogation and sub-wavelength resolution in thin plates with embedded metamaterial acoustic lenses},
author = {Semperlotti, F., E-mail: fsemperl@nd.edu and Zhu, H.},
abstractNote = {In this study, we present an approach to ultrasonic beam-forming and high resolution identification of acoustic sources having critical implications for applications such as structural health monitoring. The proposed concept is based on the design of dynamically tailored structural elements via embedded acoustic metamaterial lenses. This approach provides a completely new alternative to conventional phased-array technology enabling the formation of steerable and collimated (or focused) ultrasonic beams by exploiting a single transducer. Numerical results show that the ultrasonic beam can be steered by simply tuning the frequency of the excitation. Also, the embedded lens can be designed to achieve sub-wavelength resolution to clustered acoustic sources, which is a typical scenario encountered in incipient structural damage.},
doi = {10.1063/1.4892017},
journal = {Journal of Applied Physics},
number = 5,
volume = 116,
place = {United States},
year = {Thu Aug 07 00:00:00 EDT 2014},
month = {Thu Aug 07 00:00:00 EDT 2014}
}
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  • In this paper, we present an approach to ultrasonic beam-forming and beam-steering in structures based on the concept of embedded acoustic metamaterial lenses. The lens design exploits the principle of acoustic drop-channel that enables the dynamic coupling of multiple ultrasonic waveguides at selected frequencies. In contrast with currently available technology, the embedded lens allows exploiting the host structure as a key component of the transducer system therefore enabling directional excitation by means of a single ultrasonic transducer. The design and the performance of the lens are numerically investigated by using Plane Wave Expansion and Finite Difference Time Domain techniques appliedmore » to bulk structures. Then, the design is experimentally validated on a thin aluminum plate waveguide where the lens is implemented by through-holes. The dynamic response of the embedded lens is estimated by reconstructing, via Laser Vibrometry, the velocity field induced by a single source located at the center of the lens.« less
  • Abstract not provided.