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SK Datta

Publications and source records attributed to SK Datta.

9 recordsLinked to original sources
PubMed2000

On approximating guided waves in plates with thin anisotropic coatings by means of effective boundary conditions

In this paper, effective boundary conditions for elastic wave propagation in plates with thin coatings are derived. These effective boundary conditions are used to obtain an approximate dispersion relation for guided waves in an isotropic plate with thin anisotropic coating layers. The accuracy of the effective boundary conditions is investigated numerically by comparison with exact solutions for two different material systems. The systems considered consist of a metallic core with thin superconducting coatings. It is shown that for wavelengths long compared to the coating thickness there is excellent agreement between the approximate and exact solutions for both systems. Furthermore, numerical results presented might be used to characterize coating properties by ultrasonic techniques.

Journal Article↗
PubMed2000

On ultrasonic guided waves in a thin anisotropic layer lying between two isotropic layers

In this paper, dispersion of guided waves in a three-layered sandwich plate is considered. The focus here is on a configuration consisting of a thin anisotropic layer sandwiched between two identical isotropic layers. This configuration could model, for example, a superconducting tape where the middle layer is a brittle superconductor and the surrounding layers are isotropic and ductile. An approximate dispersion relation correct to O(h) governing the guided waves is obtained by expanding the field inside the thin middle layer in powers of the small thickness h of the layer. Numerical examples are given for two specific systems with superconducting middle layers. Some characteristic features, particularly at low frequencies, are investigated. Comparison between the exact and approximate dispersion relations are made to show that the approximation works well in the frequency interval of interest. The characteristic features may be useful for ultrasonic measurements of the anisotropic elastic constants of the thin layer.

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