Santan Kumar

Effect of smooth moving punch in an initially stressed monoclinic magnetoelastic crystalline medium due to shear wave propagation

This work studies the effect of a semi-infinite smooth moving punch on the shear wave propagation in an initially stressed magnetoelastic monoclinic strip. The closed form expression of dynamic stress concentration due to the punch for the force of a constant intensity has been established. The speed of moving punch associated with shear wave speed in the medium, vertical compressive initial stress, vertical tensile initial stress and monoclinic magnetoelastic coupling parameter have a substantial effect on the dynamic stress concentration owing to a semi-infinite smooth moving punch. Numerical computation and graphical demonstration has been carried out for quartz crystal with monoclinic symmetry to observe the profound effect of these affecting parameters on dynamic stress concentration. In order to highlight some of the important peculiarities of the problem, a comparative study of dynamic stress concentration in an initially stressed magnetoelastic monoclinic strip and initially stressed magnetoelastic isotropic strip has been made. Weiner-Hopf technique indicated by Matczynski has been adopted to solve the problem. In particular, some special cases have been deduced from the obtained expression of dynamic stress concentration due to the smooth moving punch.

Love-type wave propagation in a corrugated piezoelectric structure

This study delves into the propagation of Love-type wave in a corrugated piezoelectric layer overlying an isotropic elastic half-space. The expression of dispersion relation has been established in a closed form for both the cases of electrically open condition and electrically short condition. The pronounced effect of various affecting parameters, namely wave number, corrugation parameter of upper boundary surface, corrugation parameter of common interface between the layer and the half-space, piezoelectric constant and dielectric constant of corrugated piezoelectric layer, undulation parameter and position parameter on the phase velocity of Love-type wave, has been remarkably traced out. In order to observe the prominent effect of these affecting parameters on the phase velocity of Love-type wave, numerical computation and graphical demonstration have been accomplished for specific type of corrugated boundary surfaces present in the layer. Moreover, comparative study has been wrapped up to reveal the latent characteristics of the problem by means of graphical illustrations for both the cases of electrically open and electrically short conditions. As a special case of the problem, it is observed that procured dispersion relation for both the cases of electrically open condition and electrically short condition is in well agreement with the classical Love wave equation.

Propagation of Torsional Waves in a Fiber Composite Layer Lying over an Initially Stressed Viscoelastic Half-Space

AbstractThe present study investigates the possibility of torsional surface wave propagation in a fiber composite layer lying over an initially stressed viscoelastic half-space. The closed-form expression for the dispersion relation and damping equation has been obtained. Viscoelasticity of the lower half-space, reinforcement, wave number, and horizontal compressive/tensile initial stress acting in an initially stressed lower half-space have substantial effect on the dispersion curve. For the sake of comparative study, numerical computation and graphical demonstration have been carried out by considering some of the special cases of the problem in addition to the problem itself. A remarkable finding is that reinforcement in the superficial layer favors more the phase velocity and damped velocity of a torsional surface wave as compared with the reinforced free superficial layer. As a special case of the problem, it is found that the obtained dispersion relation is well in agreement with the classical Love ...

Influence of rectangular and parabolic irregularities on the propagation behavior of transverse wave in a piezoelectric layer: A comparative approach

Purpose The purpose of this paper is to theoretically analyze the propagation of Love-type wave in an irregular piezoelectric layer superimposed on an isotropic elastic substrate. Design/methodology/approach The perturbation technique and Fourier transform have been applied for the solution procedure of the problem. The closed-form expressions of the dispersion relation have been analytically established considering different type of irregularities, namely, rectangular and parabolic for both the cases of electrically open and short conditions. Findings The study reveals that the phase velocity of Love-type wave is prominently influenced by wave number, size of irregularity, piezoelectric constant and dielectric constant of an irregular piezoelectric layer. Numerical simulation and graphical illustrations have been effectuated to depict the pronounced impact of aforementioned affecting parameters on the phase velocity of Love-type wave. The major highlight of the paper is the comparative study carried out for rectangular irregularity and parabolic irregularity in both electrically open and short conditions. Classical Love wave equation has been recovered for both the electrical conditions as the limiting case when both media are elastic and interface between them is regular. Practical implications The consequences of the study can be utilized in the design of surface acoustic wave devices to enhance their efficiency, as the material properties and the type of irregularities present in the piezoelectric layer enable Love-type wave to propagate along the surface of the layer promoting the confinement of wave for a longer duration. Originality/value Up to now, none of the authors have yet studied the propagation of Love waves in a piezoelectric layer overlying an isotropic substrate involving both parabolic and rectangular irregularities. Further, the comparative study of rectangular irregularity and parabolic irregularity for both the cases of electrically open and short conditions elucidating the latent characteristics is among the major highlights and reflects the novelty of the present study.

Analysis of Stresses Induced due to a Moving Load on Irregular Initially Stressed Heterogeneous Viscoelastic Rock Medium

AbstractThis paper investigates the normal and shear stresses induced due to a load moving on initially stressed irregular heterogeneous isotropic viscoelastic rock medium (sandstone, limestone, an...