Inverse characterization of plates using zero group velocity Lamb modes
نویسندگان
چکیده
منابع مشابه
Influence of the anisotropy on zero-group velocity Lamb modes.
Guided waves in a free isotropic plate (symmetric S(n) and antisymmetric A(n) Lamb modes) exhibit a resonant behavior at frequencies where their group velocity vanishes while their phase velocity remains finite. Previous studies of this phenomenon were limited to isotropic materials. In this paper, the optical generation and detection of these zero-group velocity (ZGV) Lamb modes in an anisotro...
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Hollow cylinders used in the industry must be regularly inspected. Elastic guided waves, similar to Lamb modes in a plate, can propagate in the axial direction or around the circumference. They are sensitive to geometrical and mechanical parameters of the cylindrical shell. The objective of this paper is to show that zero group velocity (ZGV) Lamb modes can be used to bring out anisotropy and t...
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A non-contact laser based ultrasonic technique is proposed for detecting plate thickness variations due to corrosion and adhesive disbonds between two plates. The method exploited the resonance at the minimum frequency of the S1 Lamb mode dispersion curve. At this minimum frequency the group velocity vanishes, whereas the phase velocity remains finite. The energy deposited by the laser pulse, g...
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Elastic plates or cylinders can support guided modes with zero group velocity (ZGV) at a nonzero value of the wave number. Using laser-based ultrasonic techniques, we experimentally investigate some fascinating properties of these ZGV modes: resonance and ringing effects, backward wave propagation, interference between backward and forward modes. Then, the conditions required for the existence ...
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The well known zero in the group velocity of the first-order symmetric (S1) plate wave mode has been exploited in air-coupled ultrasonic imaging to obtain significantly higher sensitivity than can be achieved in conventional air-coupled scanning. At the zero group velocity point at the frequency minimum of the S1 mode, a broad range of wavenumbers couple into the first-order symmetric mode at n...
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ژورنال
عنوان ژورنال: Ultrasonics
سال: 2016
ISSN: 0041-624X
DOI: 10.1016/j.ultras.2015.10.015