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Ultrasonic Lamb wave inspection of composite defects
Health Monitoring of Structural and Biological Systems IX, 2020Composites have been extensively used in aerospace engineering due to their advantages of light weight, high strength, and engineering design flexibility. Manufacturing defects such as wrinkle and porosity can affect the performance of the composites and may lead to failure in the end, while damage such as delamination, fiber fraction, and matrix ...
Zhaoyun Ma, Lingyu Yu
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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 wave detection of a channel in a double-casing well
Ultrasonics, 2023In cement-bonding evaluation, channel detection by ultrasonic Lamb waves has been widely studied and applied in single-casing wells. However, its feasibility in double-casing wells remains unknown. The relationship between ultrasonic Lamb waves and channels based on finite-difference time-domain simulations was investigated.
Da, Chen +4 more
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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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Propagation of ultrasonic Lamb waves in piezoelectric plates
Journal of Applied Physics, 1991The propagation of the lowest-order symmetric (S0) and antisymmetric (A0) Lamb wave modes in a piezoelectric plate is investigated both theoretically as well as experimentally. The characteristics of the modes and their relation to the surface acoustic wave is modified by electrical boundary conditions on the plate surfaces.
S. G. Joshi, Y. Jin
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An anisotropic ultrasonic transducer for Lamb wave applications
Smart Structures and Systems, 2016An anisotropic ultrasonic transducer is proposed for Lamb wave applications, such as passive damage or impact localization based on ultrasonic guided wave theory. This transducer is made from a PMNPT single crystal, and has different piezoelectric coefficients d31 and d32, which are the same for the conventional piezoelectric materials, such as Lead ...
Wensong Zhou, Hui Li, Fuh-Gwo Yuan
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Coupling of interdigital transducer to ultrasonic Lamb waves
Applied Physics Letters, 1991The coupling of an interdigital transducer to ultrasonic Lamb waves propagating in a piezoelectric plate has been calculated using Green’s function method. It is found that when the plate thickness is more than a few acoustic wavelengths, the lowest order symmetric (S0) and antisymmetric (A0) modes are almost equally generated. The slight difference in
Yu Jin, Shrinivas G. Joshi
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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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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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