This page shows some examples of multimedia files. It is also available at: http://www.ieee-uffc.org/tr/mexample.pdf. For submission of multimedia manuscripts to TUFFC, please follow “Information for Contributors” at: http://www.ieeeuffc.org/tr/contrib.pdf. Multimedia Example Created by Jian-yu Lu, Editor-in-Chief, 07/07/03 IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society 1. Color Figure: The IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control (TUFFC) now accepts color figures online with corresponding grayscale figures in print without additional charges if authors follow the multimedia manuscript submission procedure in the “Information for Contributors”. The “color figures” icon below indicates in the print that a color version of the figure is available online. It also links to the color figure submitted originally by the authors for viewing details. Because of the sizes of color figures and the additional editorial work such as making two sets of PostScript files in which they remain identical after replacing grayscale with color, authors should request color figures online only when it is necessary. The color figure must be in JPEG (Joint Photographic Expert Group) or GIF (Graphics Interchange Format) format to reduce file size and to decrease the bandwidth usage on the TUFFC server. Fig. 1. An eight-layer printed circuit board (PCB) used primarily for multi-channel ultrasound signal reception and storage. The board was designed in the Ultrasound Lab at The University of Toledo, led by Dr. Jian-yu Lu. It is one of the many PCBs designed for a high-frame rate medical ultrasound imaging system [1], which consists of 128 linear, ±144V peak, 0.05-10MHz, and 12-bit arbitrary waveform generators for the production of ultrasound signals or for other research purposes. 2. Movies: Please click on the movie icon to see a movie. The two movies below give you an idea on the file size versus movie quality. “VCD quality” here means 1150kbits/s for video and 224kbits/s for 16-bit MP2 stereo audio at 44.1KHz sampling rate. Fig. 2. An introduction to the Ultrasound Lab at The University of Toledo. 3. Movies and Animations: Please click on the movie icons to see movies or animations. Fig. 3. Circuit design and construction of the imaging system. 4. Movies and Animation: Please click on the movie icons to see movies or animation. Movie [File size: 785KB; Format: MPEG1; Resolution: 320X240; Duration: 9 seconds]

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control

Emergence of Seismic Metamaterials: Current State and Future Perspectives

Ultrasonic guided waves have been used successfully in structural health monitoring systems to detect damage in isotropic and composite materials with simple and complex geometry. A limitation of c...

/pdf/open-guided-waves-online-platform-for-ultrasonic-guided-wave-2n1jecbev9.pdf

Open Guided Waves: online platform for ultrasonic guided wave measurements:

The advancement in electromagnetic metamaterials, which commenced three decades ago, experienced a rapid transformation into acoustic and elastic systems in the forms of phononic crystals and acoustic/elastic metamaterials. Since its early discovery, numerous wave phenomena alongside the possible engineering applications have been highlighted. The existing and emerging fields of metamaterials are far more extensive, ranging from optics to acoustic, and all the way to the elastic systems. Numerous fantastic dynamic properties in optics and acoustic/elastic systems have been reported to date, which cannot be found in naturally occurring materials. The present review tends to discuss the historical context, current progresses and possible future outcomes of metamaterials. The fascinating phenomena observed in optics/electromagnetic metamaterials have been explained and linked with acoustic and elastic counterparts. The idea of perfect lens that is governed by negative permittivity and negative permeability via left-handed materials with negative refractive index properties and the transformation optics for invisibility cloaks and optical rainbow effect alongside the hyperbolic metamaterials are reviewed and discussed. Furthermore, the associated transformation into acoustic and elastic focusing effects via graded index metamaterials, acoustic/elastic invisibility cloaks, transformational acoustics, and seismology and metawedges resembling optical rainbow effects and the likes are explained. The present state of the art has been examined and the physics involved in the governing of those peculiar wave mechanisms has been highlighted. Starting from photonic crystals, phononic crystals and acoustic metamaterials, the present state of the art research in some subfields of acoustic metamaterials has been outlined, such as metasurfaces, topological phononic crystals and seismic metamaterials, the three exciting and emerging research topics. The substantial challenges involved in these realms are characterised and the possible future outcome is further evaluated. This review article may assist researchers and engineers to grasp the idea of metamaterials in not only photonic and phononic crystal systems, but also the counterpart subfields.

From Photonic Crystals to Seismic Metamaterials: A Review via Phononic Crystals and Acoustic Metamaterials

Metabarriers with multi-mass locally resonating units for broad band Rayleigh waves attenuation

Metasurfaces of mechanical resonators have been successfully used to control in-plane polarized surface waves for filtering, waveguiding and lensing applications across different length scales. In this work, we extend the concept of metasurfaces to anti-plane surface waves existing in semi-infinite layered media, generally known as Love waves. By means of an effective medium approach, we derive an original closed-form dispersion relation for the metasurface. This relation reveals the possibility to control the Love waves dispersive properties by varying the resonators mechanical parameters. We exploit this capability to manipulate the metasurface refractive index and design two gradient index (GRIN) metalenses, i.e. a Luneburg lens and a Maxwell lens. We confirm the performance of the designed lenses using full 3D finite element simulations. Our work demonstrates the possibility of realizing wave control devices for anti-plane waves.

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Control of Love waves by resonant metasurfaces.

Elastic metasurfaces can manipulate the propagation of surface acoustic waves (SAWs) for applications as wave filters, including barriers for seismic surface waves---earthquake protection, that is. Efforts so far have focused on homogenous media, in crude approximation of the real world. The authors study the dynamics of an elastic metasurface in an unconsolidated granular medium, which presents an inhomogeneous stiffness profile. The metasurface's resonance hybridizes the lowest-order SAW and down-converts all higher-order SAWs, preventing the surface-wave delocalization seen in homogeneous media. These findings could impact protective designs for inhomogeneous stratified soils.

/pdf/hybridization-of-guided-surface-acoustic-modes-in-yppmpqqg05.pdf

Hybridization of Guided Surface Acoustic Modes in Unconsolidated Granular Media by a Resonant Metasurface

One of the main challenges faced by the structural health monitoring community is acquiring and processing huge sets of acoustic wavefield data collected from sensors, such as scanning laser Doppler vibrometers or ultrasonic scanners. In fact, extracting information that allows the estimation of the damage condition of a structure can be a time-consuming process. This paper presents a damage detection and localization technique based on a compressive sensing algorithm, which significantly allows us to reduce the acquisition time without losing in detection accuracy. The proposed technique exploits the sparsity of the wavefield in different representation domains, such as those spanned by wave atoms, curvelets, and Fourier exponentials to recover the full wavefield and, at the same time, to infer the damage location, based on comparison between the wavefield reconstructions produced by the different representation domains. The procedure is applied to three different setups related to an aluminum plate with a notch, a glass fiber reinforced polymer plate with a notch, and a composite plate with a delamination. The results show that the technique can be applied in a variety of structural components to reduce acquisition time and achieve high performance in defect detection and localization by removing up to 80% of the Nyquist sampling grid.

Alessandro Marzani

Papers

Metabarriers with multi-mass locally resonating units for broad band Rayleigh waves attenuation

Control of Love waves by resonant metasurfaces.

Hybridization of Guided Surface Acoustic Modes in Unconsolidated Granular Media by a Resonant Metasurface

Full Wavefield Analysis and Damage Imaging Through Compressive Sensing in Lamb Wave Inspections

Spiral-shaped piezoelectric sensors for Lamb waves direction of arrival (DoA) estimation