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Modulating Lamb waves with a tunable ultrasonic lens
Health Monitoring of Structural and Biological Systems XV, 2021This paper presents a tunable ultrasonic lens for the flexible control and modulation of Lamb waves. The lens is comprised of layered slice structures using Shape Memory Alloy (SMA) which could change its material properties under thermal loads. Numerical investigations on the wave dispersion characteristics demonstrate the tuning capability of wave ...
Xiaowei Yin, Yanfeng Shen, Xianggui Qin
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Propagation Characteristic of Ultrasonic Lamb Wave
Applied Mechanics and Materials, 2012Ultrasonic wave transmitted in the plate is called Lamb wave. The dispersion characteristic of Lamb wave makes it very complicated to be used in material Nondestructive Testing (NDT). In order to solve this problem, the analysis of frequency-dispersion characteristic of Lamb wave is made in this paper, and the dispersion curves of the Lamb wave in ...
Xiao Chen, Kai Xu
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Sparse Array Ultrasonic Lamb Wave TDTE Imaging Method
IEEE Sensors Journal, 2021The current Lamb wave topology imaging methods are limited to the ideal model of through-hole defects, ignoring the influence of mode coupling. However, blind hole defects, such as structural plate corrosion and cracks, are the most likely defects in practical applications, and Lamb waves are bound to appear mode-coupled at these defects.
null Yao-Cheng +7 more
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Silicon-based ultrasonic Lamb-wave multisensors
IEEE Technical Digest on Solid-State Sensor and Actuator Workshop, 2003Initial experimental, analytical, and numerical evaluations are described of a microsensor that uses ultrasonic Lamb wave propagating in a thin plate supported by a silicon die. Because it is sensitive to many measurands, the device could operate as a microphone, biosensor, chemical vapor or gas detector, scale, pressure sensor, densitometer ...
S.W. Wenzel, R.M. White
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Microtransport induced by ultrasonic Lamb waves
Applied Physics Letters, 1991We have observed pumping of water induced by 4.7 MHz ultrasonic Lamb waves traveling in a 4-μm-thick composite membrane of silicon nitride and piezoelectric zinc oxide. The observed pumping speed is proportional to the square of the wave amplitude; the speed was 100 μm/s for a rf drive voltage of 8 V and a 6.5 nm wave amplitude. A nonlinear model based
R. M. Moroney, R. M. White, R. T. Howe
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Ultrasonic lamb waves in a thin plate
SPIE Proceedings, 2003ABSTRACT The behavior of the wave field produced in a thin unidirectional graphite/epoxy composite plate by a dynamic point load is studied using an approximate shear deformation plate theory (S.D.P.T) and a finite element analysis (F.E.A). Comparisons are made for propagation at 0 o , 45 , and 90 directions relative to the fibers showing excellent ...
Ajit K. Mal +2 more
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Lamb Wave Helical Ultrasonic Tomography
AIP Conference Proceedings, 2004Ultrasonic guided waves have been used for a wide variety of ultrasonic inspection techniques. We describe here a new variation called helical ultrasound tomography (HUT). This new technique, among other things, has direct application to advanced pipe inspection.
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Fluid motion produced by ultrasonic Lamb waves
IEEE Symposium on Ultrasonics, 2002Fluid motion induced by traveling flexural waves in 4- mu m-thick membranes was observed using 2.5- mu m-diameter polystyrene spheres in water to make their fluid motion visible. Visual observation of the spheres indicates that their velocity is in the direction of wave propagation and is proportional to the square of the acoustic amplitude.
R.M. Moroney, R.M. White, R.T. Howe
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Electromechanical coupling coefficients of ultrasonic Lamb waves
The Journal of the Acoustical Society of America, 1993The electromechanical coupling coefficients of fundamental and higher-order ultrasonic Lamb wave modes propagating in a piezoelectric plate have been calculated using two different methods. The first approach calculates the coupling coefficient K from the well-known equation K2=2(Δv/v)=2(v0−vm)/v0, where v0 and vm are the wave velocities on a free and ...
Shrinivas G. Joshi, Yu Jin
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Capacitive micromachined ultrasonic Lamb wave transducers using rectangular membranes
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2003This paper details the theory, fabrication, and characterization of a new Lamb wave device. Built using capacitive micromachined ultrasonic transducers (CMUTs), the structure described uses rectangular membranes to excite and receive Lamb waves on a silicon substrate.
Mohammed H, Badi +5 more
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