Rehena Sultana - Academia.edu (original) (raw)
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Observatoire Midi-Pyrénées, Université de Toulouse III Paul Sabatier
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Papers by Rehena Sultana
Journal of Vibration and Control, 2014
ABSTRACT In this short communication, a mathematical model for torsional wave propagation in a po... more ABSTRACT In this short communication, a mathematical model for torsional wave propagation in a porous crustal layer lying over an anisotropic inhomogeneous half-space has been studied. This study reveals that the inhomogeneity in the half-space is assumed to be present in the directional rigidities and density. The anisotropy nature of the half-space is due to the presence of initial stress. Bessels functions are taken to solve the problem and the frequency equations governing the propagation of torsional waves are derived. It has been observed that there are three sets of torsional wave fronts and one shear wave front. Each set of torsional wave front has a pronounced effect on phase velocity, whereas shear wave front remains un-affected. Numerical treatment is applied to seek these effects on phase velocity of the existing waves and presented graphically. Graphical user interface has been developed using MATLAB to generalize the effect of the various parameters discussed.
Journal of Earth System Science, 2015
The present work illustrates a theoretical study on the effect of rigid boundary for the propagat... more The present work illustrates a theoretical study on the effect of rigid boundary for the propagation of torsional surface wave in an inhomogeneous crustal layer over an inhomogeneous half space. It is believed that the inhomogeneity in the half space arises due to hyperbolic variation in shear modulus and density whereas the layer has linear variation in shear modulus and density. The dispersion equation has been obtained in a closed form by using Whittaker's function, which shows the variation of phase velocity with corresponding wave number. Numerical results show the dispersion equations, which are discussed and presented by means of graphs. Results in some special cases are also compared with existing solutions available from analytical methods, which show a close resemblance. It is also observed that, for a layer over a homogeneous half space, the velocity of torsional waves does not coincide with that of Love waves in the presence of the rigid boundary, whereas it does at the free boundary. Graphical user interface (GUI) software has been developed using MATLAB 7.5 to generalize the effect of various parameter discussed.
Journal of Vibration and Control, 2014
ABSTRACT In this short communication, a mathematical model for torsional wave propagation in a po... more ABSTRACT In this short communication, a mathematical model for torsional wave propagation in a porous crustal layer lying over an anisotropic inhomogeneous half-space has been studied. This study reveals that the inhomogeneity in the half-space is assumed to be present in the directional rigidities and density. The anisotropy nature of the half-space is due to the presence of initial stress. Bessels functions are taken to solve the problem and the frequency equations governing the propagation of torsional waves are derived. It has been observed that there are three sets of torsional wave fronts and one shear wave front. Each set of torsional wave front has a pronounced effect on phase velocity, whereas shear wave front remains un-affected. Numerical treatment is applied to seek these effects on phase velocity of the existing waves and presented graphically. Graphical user interface has been developed using MATLAB to generalize the effect of the various parameters discussed.
Journal of Earth System Science, 2015
The present work illustrates a theoretical study on the effect of rigid boundary for the propagat... more The present work illustrates a theoretical study on the effect of rigid boundary for the propagation of torsional surface wave in an inhomogeneous crustal layer over an inhomogeneous half space. It is believed that the inhomogeneity in the half space arises due to hyperbolic variation in shear modulus and density whereas the layer has linear variation in shear modulus and density. The dispersion equation has been obtained in a closed form by using Whittaker's function, which shows the variation of phase velocity with corresponding wave number. Numerical results show the dispersion equations, which are discussed and presented by means of graphs. Results in some special cases are also compared with existing solutions available from analytical methods, which show a close resemblance. It is also observed that, for a layer over a homogeneous half space, the velocity of torsional waves does not coincide with that of Love waves in the presence of the rigid boundary, whereas it does at the free boundary. Graphical user interface (GUI) software has been developed using MATLAB 7.5 to generalize the effect of various parameter discussed.