Journal ArticleDOI
Tank measurements of scattering from a resin-filled fiberglass spherical shell with internal flaws
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TLDR
Results of acoustic inversion and structural health monitoring achieved by means of low to midfrequency elastic scattering analysis of simple, curved objects, insonified in a water tank are presented.Abstract:
This paper presents results of acoustic inversion and structural health monitoring achieved by means of low to midfrequency elastic scattering analysis of simple, curved objects, insonified in a water tank. Acoustic elastic scattering measurements were conducted between 15 and 100kHz on a 60-mm-radius fiberglass spherical shell, filled with a low-shear-speed epoxy resin. Preliminary measurements were conducted also on the void shell before filling, and on a solid sphere of the same material as the filler. These data were used to estimate the constituent material parameters via acoustic inversion. The objects were measured in the backscatter direction, suspended at midwater, and insonified by a broadband directional transducer. From the inspection of the response of the solid-filled shell it was possible to detect and characterize significant inhomogeneities of the interior (air pockets), the presence of which were later confirmed by x-ray CT scan and ultrasound measurements. Elastic wave analysis and a mo...read more
Citations
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Journal ArticleDOI
Radiation force of a helicoidal Bessel beam on a sphere
TL;DR: The partial-wave series for the scattering of an acoustic helicoidal Bessel beam by a sphere centered on the axis of the beam is applied to the calculation of the acoustic radiation force by the beam on the sphere in an inviscid fluid.
Journal ArticleDOI
Benchmark problems for acoustic scattering from elastic objects in the free field and near the seafloor.
TL;DR: Overall, FE- and BE-based models emerge as those being capable of treating a wider class of problems in terms of target geometry, with the FE method having the additional advantage of being able to deal with complex internal structures without much additional effort.
Journal ArticleDOI
Boundary effects on backscattering by a solid aluminum cylinder: experiment and finite element model comparisons (L).
TL;DR: Backscattering of sound by a solid aluminum cylinder was measured in the free field and with the cylinder near a flat surface to simulate some aspects of backscattering when resting on the seabed.
Journal ArticleDOI
Detection of damages in underwater metal plate using acoustic inverse scattering and image processing methods
TL;DR: In this paper, a robust and simple method was proposed to detect and localize a possible damage in 2D images based on image processing and analysis, and the detection rate for crack damage reached 100% and localization accuracy reached 96% on average.
Dissertation
Sonar systems for object recognition
TL;DR: This thesis is dedicated to the study of the present and the future of acoustic sensors for detection, identification or survey and shows that object echoes can contain essential information concerning its structure and/or composition.
References
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Book
Acoustics: An Introduction to Its Physical Principles and Applications
TL;DR: Pierces as mentioned in this paper is a classic text on acoustics with a rich history and development of the field of sound and acoustical engineering. But he organizes it superbly and writes intelligently with a wonderful way of integrating the history and evolution of the science and the graphics are exceptionally clear and communicative.
Journal ArticleDOI
Guided Lamb waves for identification of damage in composite structures: A review
Zhongqing Su,Lin Ye,Ye Lu +2 more
TL;DR: A comprehensive review on the state of the art of Lamb wave-based damage identification approaches for composite structures, addressing the advances and achievements in these techniques in the past decades, is provided in this paper.
Journal ArticleDOI
On the determination of phase and group velocities of dispersive waves in solids
Wolfgang Sachse,Yih-Hsing Pao +1 more
TL;DR: In this article, a new technique is developed to determine the dispersion relation and the propagational speeds of waves in dispersive solids, which can be applied to measurements of acoustic or electromagnetic wave speeds in other dispersive media.
Journal ArticleDOI
Analysis of boundary conditions for elastic wave interaction with an interface between two solids
Stanislav I. Rokhlin,Y. J. Wang +1 more
TL;DR: The boundary conditions for an interface between two solids are analyzed to model a thin viscoelastic interface layer in this article, where the applicability of such boundary conditions is analyzed by comparison with exact solutions for ultrasonic wave reflection.