Showing papers by "Subhendu K. Datta published in 2004"
TL;DR: In this paper, an analysis of the propogation of thermoelastic waves in a homogeneous, anisotropic, thermally conducting plate has been presented in the context of the generalized Lord-Shulman theory of thermasticity.
Abstract: An analysis of the propogation of thermoelastic waves in a homogeneous, anisotropic, thermally conducting plate has been presented in the context of the generalized Lord-Shulman theory of thermoelasticity. Three different methods are used in this analysis: two of them are exact and the third is a semianalytic finite element method (SAFE). In our exact analysis, two different approaches are used. The first one, which is applicable to transversely isotropic plate, is based on introducing displacement potential functions, whereas in the second approach, which is applicable to any triclinic material, we rewrite the governing equations and boundary conditions in a matrix form. Finally, in the SAFE method, the plate is discretized along its thickness using N parallel, homogeneous layers, which are perfectly bonded together. Frequency spectrum and dispersion curves are obtained using the three methods and are shown to agree well with each other. The effects of thermal relaxation time and coupling term are also i...
41 citations
TL;DR: In this paper, the authors investigated the acoustic mode coupling (pinching) phenomena for phonon transport in anisotropic bi-layered plates with finite width and showed significant influence of the plate aspect ratio on the dispersion and transient wave response.
Abstract: Transient ultrasonic guided waves in anisotropic bi‐layered plates with finite‐width are investigated in this paper Composite bi‐layered plates consisting of GaAs substrate coated with Nb sheath is considered as an example because of its application to electronics and calorimetry The purpose is to investigate the acoustic mode coupling (“pinching”) phenomena for phonon transport A semi‐analytical finite element (SAFE) method is adopted to study the guided wave dispersion behavior in finite‐width elastic plates Nine‐noded quadrilateral elements are used to model the cross section of the finite‐width plate Propagation in the axial direction is modeled by analytical wave functions Elastodynamic Green’s functions are derived using modal summation in the frequency‐wavenumber and time‐space domains Results for dispersion and transient analysis of guided waves in finite‐width plates are presented and compared for different aspect ratios Group velocities are calculated and wave arrival times are computed for different plate cross sections as well as different excitation frequency Numerical results show significant influence of the plate aspect ratio on the dispersion and transient wave response Complex nature of quasi‐mode dispersion and propagation due to pinching phenomena in anisotropic plates require such quantitative analysis to afford easy interpretation These results would be important for nondestructive material evaluation and for characterization of phonon transport in anisotropic bi‐layered plates
12 citations