Transfer and Green functions based on modal analysis for Lamb waves generation

Núñez, I.; Ing, Ros Kiri; Negreira, Carlos; Fink, Mathias

doi:10.1121/1.428623

Cited by 38 publications

(12 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Common techniques use liquid 26 and solid 27 wedges attached to the transducers to excite Lamb waves. However, considering the geometry of the array, a simple piezoceramic disk at its center is found to be more appropriate to our purposes.…”

Section: Resultsmentioning

confidence: 99%

Engineering surface waves in flat phononic plates

et al. 2012

View full text Add to dashboard Cite

Surface acoustic-wave phenomena span a wide range of length scales going from the devastation of earthquakes down to image reconstruction of buried nanostructures. In solid-fluid systems, the so-called Scholte-Stoneley waves (SSWs) dominate the scene at the interface with their evanescent fields decaying away into both media. Understanding and manipulating these waves in patterned surfaces would enable new applications of sound to be devised for imaging and acoustic signal processing, although this task has so far remained elusive. Here, we report SSW modes displaying directional gaps and band folding in fluid-loaded solid phononic plates. The plates are inhomogeneously patterned with in-plane periodic modulations of the elastic constants, but present flat surfaces free of corrugations. We experimentally demonstrate control of SSWs, which opens a promising route toward acoustic fluid sensing, microscopy, and signal processing.

show abstract

Section: Resultsmentioning

confidence: 99%

Engineering surface waves in flat phononic plates

et al. 2012

View full text Add to dashboard Cite

show abstract

“…These filter factors ⌰ m () arise from the Green functions for Lamb waves 11 called H xx (m) () in the referred paper. They can be calculated in function of the amplitude of the normal displacement W (m) () on the plate surface, and in function of the average flow power per unit length 14 P m () for each mode m, as…”

Section: A Lamb Wavesmentioning

confidence: 99%

“…We use a transfer function for Lamb waves, which we found in a previous work, 11 and we apply it to define a TR transfer function for two-dimensional waves in dispersive media with multimode propagation.…”

Section: Introductionmentioning

confidence: 99%

Efficiency parameters in time reversal acoustics: Applications to dispersive media and multimode wave propagation

Núñez

Negreira

2005

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

This paper develops a theoretical background for the interpretation of the time reversal ͑TR͒ processes applied to the refocalization of acoustic waves in dispersive media with multimode propagation of waves. Two parameters are introduced in order to measure the efficiency of signal recompression in TR processes: spatial and temporal efficiencies. It is demonstrated that the signal recompression enhances when the medium is highly dispersive, when there are several modes involved in the process, and when the angular aperture of the TR mirror is appreciable. These results are applied to Lamb waves recompression in thin plates and focalization efficiencies in longitudinal and transversal directions are deduced. Finally, these theoretical results are compared with the experimental ones obtained for different plate thicknesses.

show abstract

“…Other authors have used the 2D FT method to characterize Lamb waves using different excitation and detection schemes. The aforementioned wedge method is reversible and can be employed both for the generation [10][11][12][13][14][15] and detection 15 of the waves. Other reversible methods were also used to acquire the experimental data, such as air-coupled transducers 16,17 and immersion transducers in a liquid-filled cell.…”

Section: Introductionmentioning

confidence: 99%

Characterization of guided acoustic waves in an arbitrary direction with full-field instantaneous maps of the acoustic displacement

Deán-Ben

Trillo

Doval

et al. 2012

Journal of Applied Physics

View full text Add to dashboard Cite

The full-field optical measurement of guided acoustic waves presents important advantages derived from the capability to map the acoustic field in a two dimensional region, so that acoustic information over a large area can be retrieved with each measurement. In this work, we introduce an extension of the well-established two dimensional spatio-temporal Fourier transform method to calculate the frequency spectrum of guided acoustic waves. For this, we take advantage of the unique capability of a self-developed double-pulsed television holography system to acquire the acoustic displacement field in two spatial dimensions and time. Then, the spatio-temporal Fourier transform method is expanded to three dimensions according to the nature of the experimental data, so that the frequency spectrum of the waves propagating in an arbitrary direction can be calculated. The method is tested experimentally by generating narrowband Lamb waves in an aluminium plate with a piezoelectric transducer. The good agreement between the theoretical and experimental spectra in a broad zone anticipates the applicability of the method to characterize guided acoustic waves as a function of the propagation direction in materials or structures presenting anisotropic propagation behaviour.

show abstract

Transfer and Green functions based on modal analysis for Lamb waves generation

Cited by 38 publications

References 7 publications

Engineering surface waves in flat phononic plates

Engineering surface waves in flat phononic plates

Efficiency parameters in time reversal acoustics: Applications to dispersive media and multimode wave propagation

Characterization of guided acoustic waves in an arbitrary direction with full-field instantaneous maps of the acoustic displacement

Contact Info

Product

Resources

About