Showing papers by "Prabhu Rajagopal published in 2008"
TL;DR: The interaction of the fundamental shear horizontal (SH0) guided mode with part-thickness cracks in an isotropic plate is studied as an extension within the context and general framework of previous work and theoretical analysis is used to understand the physical basis for such behavior.
Abstract: The interaction of the fundamental shear horizontal (SH0) guided mode with part-thickness cracks in an isotropic plate is studied as an extension within the context and general framework of previous work [“Short range scattering of the fundamental shear horizontal guided wave mode normally incident at a through thickness crack in an isotropic plate,” J. Acoust Soc. Am. 122, 1527–1538 (2007); “Angular influence on scattering when the fundamental shear horizontal guided wave mode is incident at a through-thickness crack in an isotropic plate,” J. Acoust. Soc. Am. 124, 2021–2030 (2008)] by the authors with through-cracks. The symmetric incidence case where the principal direction of the incident beam bisects the crack face at 90° is studied using finite element simulations validated by experiments and analysis, and conclusions are inferred for general incidence angles using insights obtained with the through-thickness studies. The influence of the crack length and the monitoring distance on the specular refl...
73 citations
TL;DR: The variation of diffraction with both the angle of incidence and that of monitoring is taken up and this shows that when the first diffraction from the crack edges can be separated, its angular dependence can be obtained from literature on similar bulk elastic wave scattering problems.
Abstract: The angular influence on the scattering of cylindrical-crested waves of the fundamental shear horizontal (SH0) guided mode by through-thickness cracks in an isotropic plate is studied in the context of array imaging using ultrasonic guided waves. Finite element simulations are used to obtain trends which are subject to analytical study and experimental confirmation. The influence of the incidence angle on reflection behavior is first studied in terms of two complementary cases, that of normal incidence and that of specular reflection at various oblique incidence angles. The normal incidence study suggests that for a given incidence angle, the peak reflection is concentrated around the specular direction, while the oblique incidence studies show that maximum specular reflection occurs in the case of normal incidence. The variation of diffraction with both the angle of incidence and that of monitoring is then taken up and this shows that when the first diffraction from the crack edges can be separated, its angular dependence can be obtained from literature on similar bulk elastic wave scattering problems.
26 citations
10 Mar 2008
TL;DR: In this paper, the authors explored the relationship between the scattering from part-and through-thickness cracks in isotropic plates and proposed a framework for such a relationship, in which the scattering of circular crested SH0 waves from through-cracks were related by a suitable correction factor.
Abstract: The interaction of the fundamental shear horizontal (SH0) mode with cracks in isotropic plates in the context of array imaging using ultrasonic guided waves is a subject of continued interest to the authors. Previous work [1–3] in this regard has illuminated different aspects of the scattering of circular crested SH0 waves from through‐cracks. In this paper, the relationship between the scattering from part‐ and through‐thickness cracks is explored. First a framework for such a relationship is proposed, in which the scattering from part‐ and through‐thickness cracks are related by a suitable correction factor. The limits of the model are then tested using results from FE simulations of the problem for different configurations.
4 citations