Results 191 to 200 of about 1,378,435 (241)
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Ultrasonic Lamb wave diffraction tomography
Ultrasonics, 2001Ultrasonic guided waves, Lamb waves, allow large sections of aircraft structures to be rapidly inspected. Unlike conventional ultrasonic C-scan imaging that requires access to the whole inspected area, tomographic algorithms work with data collected over the perimeter.
E V, Malyarenko, M K, Hinders
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Scattering of Lamb waves by a circular cylinder
The Journal of the Acoustical Society of America, 2001Following our previous attempt at the scattering from a cylinder in a slab to the incidence of a guided shear wave, we hereby discuss the scattering by an elastic cylinder embedded in an isotropic plate for a variety of bonding states to incidence of the fundamental Lamb wave modes S0 and A0 at the low-frequency regime.
X M, Wang, C F, Ying
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Air-coupled Lamb wave tomography
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 1997An entirely air-coupled inspection system using a pair of micromachined silicon capacitance transducers has been used to image defects in thin plates of different materials (0.7 mm to 2.22 mm thick) using air-coupled Lamb wave tomography. A filtered back projection algorithm was used in a form of difference tomography to reconstruct images of defects ...
W, Wright +3 more
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Material interface inspection by lamb waves
International Journal of Solids and Structures, 1997zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Kundu, T., Maslov, K.
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Wideband dispersion reversal of lamb waves
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2014Ultrasonic guided waves have been widely acknowledged as the most promising tools for nondestructive evaluation (NDE). However, because of the multimodal dispersion, the received guided modes usually overlap in both time and frequency, which highly complicates the mode separation and signal interpretation.
Kailiang, Xu +4 more
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Efficient laser generation of Lamb waves
Optics Letters, 2014We report about the efficient generation of Lamb waves for nondestructive testing (NDT) of carbon fiber reinforced plastics (CFRP) with spatially formed laser beams. Therefore we describe the successful introduction of a liquid crystal on silicon (LCoS)-based spatial light modulator (SLM) to create predetermined spatial laser light distributions for a ...
Philipp, Huke +4 more
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Decoherence of lamb waves by rough interface
IEEE Ultrasonics Symposium, 2005., 2006Propagation of Lamb waves in elastic plate with a periodic grating on one interface has shown an attenuation which can be interpreted as a phenomenon of decoherence. In order to verify this hypothesis, a simplified model is considered, where a fluid plate with a limited periodic grating on one interface is studied by the finite element method (ATILA ...
Bavencoffe, M. +4 more
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Lamb Wave Multitouch Ultrasonic Touchscreen
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2016Touchscreen sensors are widely used in many devices such as smart phones, tablets, and laptops with diverse applications. We present the design, analysis, and implementation of an ultrasonic touchscreen system that utilizes the interaction of transient Lamb waves with objects in contact with the screen. It attempts to improve on the existing ultrasound
Kamyar Firouzi +3 more
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Time-frequency representations of Lamb waves
The Journal of the Acoustical Society of America, 2001The objective of this study is to establish the effectiveness of four different time-frequency representations (TFRs)—the reassigned spectrogram, the reassigned scalogram, the smoothed Wigner–Ville distribution, and the Hilbert spectrum—by comparing their ability to resolve the dispersion relationships for Lamb waves generated and detected with optical
M, Niethammer +3 more
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On conversion of Lamb waves to leaky Lamb waves in a plate partially immersed into the liquid
The Journal of the Acoustical Society of America, 1986The problem of Lamb waves diffraction on the boundary of separation of the free and immersed (into the liquid) parts of the elastic plate is theoretically analyzed. In the theoretical model, it is assumed that the free part of the plate is separated from the liquid by infinitely thin air barriers.
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