scholarly journals Wave propagation in micropolar monoclinic thermoelastic half space

2013 ◽  
Vol 18 (4) ◽  
pp. 1013-1023
Author(s):  
R.R. Gupta
Keyword(s):  
Wave Propagation ◽  
Quality Factor ◽  
Plane Strain ◽  
Half Space ◽  
Numerical Results ◽  
Plane Strain Problem ◽  
Phase Velocities ◽  
Propagation Of Waves

Abstract Propagation of waves in a micropolar monoclinic medium possessing hermoelastic properties based on the Lord- Shulman (L-S),Green and Lindsay (G-L) and Coupled thermoelasticty (C-T) theories is discussed. The investigation is divided into two sections, viz., plane strain and anti-plane strain problem. After developing the solution, the phase velocities and attenuation quality factor have been derived and computed numerically. The numerical results have been plotted graphically.

scholarly journals Investigation of Waves Generated in Transversely Isotropic Micropolar Generalized Thermoelastic Half Space Under Temperature Dependent Properties

2019 ◽  
Vol 24 (4) ◽  
pp. 53-65
Author(s):  
R.R. Gupta ◽  
R.R. Gupta
Keyword(s):  
Temperature Distribution ◽  
Quality Factor ◽  
Half Space ◽  
Elastic Properties ◽  
Transversely Isotropic ◽  
Temperature Dependent ◽  
Phase Velocities ◽  
Generalized Thermoelastic ◽  
Temperature Dependent Properties ◽  
Propagation Of Waves

Abstract The present study deals with the propagation of waves in a transversely isotropic micropolar generalized thermoelastic material possessing temperature dependent elastic properties. After developing the solution for LS, GL and CT theory, the phase velocities and attenuation quality factor have been obtained. The expressions for amplitudes of stresses, displacements, microratation and temperature distribution have been derived and computed numerically. The numerically evaluated results have been plotted graphically. Some particular cases of interest have also been obtained.

The Contact Problem for a Rigid Inclusion Pressed Between Two Dissimilar Elastic Half Planes

1981 ◽  
Vol 48 (1) ◽  
pp. 104-108
Author(s):  
G. M. L. Gladwell
Keyword(s):  
Contact Problem ◽  
Plane Strain ◽  
Integral Equations ◽  
Elastic Constants ◽  
Contact Stress ◽  
Rigid Inclusion ◽  
Numerical Results ◽  
Stress Distributions ◽  
Plane Strain Problem

Paper concerns the plane-strain problem of a rigid, thin, rounded inclusion pressed between two isotropic elastic half planes with different elastic constants. Required to find the extents of the contact regions between each plane and the inclusion, and the contact stress distributions. The governing integral equations are solved approximately by using Chebyshev expansions. Numerical results are presented.

Shear wave propagation in magneto poroelastic medium sandwiched between self-reinforced poroelastic medium and poroelastic half space

2020 ◽  
Vol 37 (9) ◽  
pp. 3345-3359
Author(s):  
Sindhuja Ala ◽  
Rajitha Gurijala ◽  
Malla Reddy Perati
Keyword(s):  
Wave Propagation ◽  
Initial Stress ◽  
Shear Wave ◽  
Half Space ◽  
Frequency Equation ◽  
Numerical Results ◽  
Poroelastic Medium ◽  
Content Type ◽  
Inhomogeneity Parameter ◽  
Heterogeneity Parameter

Purpose The purpose of this paper is to investigate the effect of reinforcement, inhomogeneity and initial stress on the propagation of shear waves. The problem consists of magneto poroelastic medium sandwiched between self-reinforced medium and poroelastic half space. Using Biot’s theory of wave propagation, the frequency equation is obtained. Design/methodology/approach Shear wave propagation in magneto poroelastic medium embedded between a self-reinforced medium and poroelastic half space is investigated. This particular setup is quite possible in the Earth crust. All the three media are assumed to be inhomogeneous under initial stress. The significant effects of initial stress and inhomogeneity parameters of individual media have been studied. Findings Phase velocity is computed against wavenumber for various values of self-reinforcement, heterogeneity parameter and initial stress. Classical elasticity results are deduced as a particular case of the present study. Also in the absence of inhomogeneity and initial stress, frequency equation is discussed. Graphical representation is made to exhibit the results. Originality/value Shear wave propagation in magneto poroelastic medium embedded between a self-reinforced medium, and poroelastic half space are investigated in presence of initial stress, and inhomogeneity parameter. For heterogeneous poroelastic half space, the Whittaker’s solution is obtained. From the numerical results, it is observed that heterogeneity parameter, inhomogeneity parameter and reinforcement parameter have significant influences on the wave characteristics. In addition, frequency equation is discussed in absence of inhomogeneity and initial stress. For the validation purpose, numerical results are also computed for a particular case.

Combined Loading of a Fully Plastic Ligament Ahead of an Edge-Crack

1986 ◽  
Vol 53 (2) ◽  
pp. 271-277 ◽  
Author(s):  
C. F. Shih ◽  
J. W. Hutchinson
Keyword(s):  
Plane Strain ◽  
Half Space ◽  
Power Law ◽  
Edge Crack ◽  
Deformation Theory ◽  
Approximate Solutions ◽  
Free Edge ◽  
Numerical Results ◽  
Combined Loading

Complete, accurate numerical results are given for the solution to the problem of a semi-infinite crack aligned perpendicularly to the free-edge of a semi-infinite half space in which the ligament is subject to arbitrary combinations of bending and tension or compression. The material is an incompressible, pure power-law deformation theory solid. Conditions of plane strain are assumed. Approximate solutions are proposed for predominantly bending loadings and also for predominantly stretching loadings.

Memory-efficient displacement-based internal friction for wave propagation simulation

Geophysics ◽  
2011 ◽  
Vol 76 (6) ◽  
pp. T131-T145 ◽  
Author(s):  
Jacobo Bielak ◽  
Haydar Karaoglu ◽  
Ricardo Taborda
Keyword(s):  
Wave Propagation ◽  
Internal Friction ◽  
Quality Factor ◽  
Half Space ◽  
Seismic Waves ◽  
Friction Model ◽  
Three Dimensions ◽  
Proposed Model ◽  
In Series ◽  
Displacement Based

The characterization of anelastic losses due to material internal friction has become increasingly important in geophysical exploration and other seismological applications, as these losses greatly affect the amplitude and dispersion of seismic waves. Anelasticity is usually specified in terms of the material’s quality factor, [Formula: see text]. Different viscoelastic models have been used to represent [Formula: see text] as a function of frequency. Most of these models are defined in terms of stresses and strains as the primary variables. Thus, in three dimensions, a separate model needs to be associated with each of the six strain components. We introduce an internal friction model that uses, instead, displacements as primary variables. For a fiber, the proposed model consists of a set of three distinct elements in parallel with different relaxation mechanisms: namely, two elements that consist of a spring and a dashpot in series (Maxwell) and a third element that consists of a spring and a dashpot in parallel (Voigt). In addition to saving memory, this formulation is particularly suitable for finite-element schemes. The model exhibits an almost constant quality factor within the frequency range of interest, with a tolerance of 5% with respect to the target [Formula: see text] value, and provides a close approximation to the variation of the phase-velocity with frequency—as has been observed in empirical data. The extension of this model to 3D anelastic problems and its use in idealized cases, such as an infinite-space, a half-space, and a layered half-space, and the comparison of results with semi-analytical reference solutions obtained from theory and previous, similar studies, corroborates the validity of the proposed model for incorporating anelastic losses in wave propagation problems.

The field from an SH point source in a continuously layered inhomogeneous half-space

1966 ◽  
Vol 56 (6) ◽  
pp. 1305-1315
Author(s):  
N. J. Vlaar
Keyword(s):  
Wave Propagation ◽  
Point Source ◽  
Half Space ◽  
Normal Modes ◽  
Continuous Functions ◽  
Physical Parameters ◽  
Source Depth ◽  
Symmetrical Form ◽  
Propagation Of Waves ◽  
Free Wave Propagation

Abstract The propagation of waves due to the presence of an SH point source in the interior of a piecewise continuously stratified half-space is studied. The physical parameters governing the wave propagation, i.e. the rigidity and the density, are assumed to be arbitrary piecewise continuous functions of depth with constant finite limiting values as depth goes to infinity. The analysis is based on spectral theory of boundary value problems associated with ordinary linear second order differential equations. It is found for the time harmonic case that the final field representations are given in the form of a finite residue series, plus a branch line integral, the first representing the normal mode contribution to the field. The field expression appears to have a symmetrical form with respect to field point depth and source depth, involving solutions connected with free wave propagation. This enables one to draw immediately conclusions regarding the influence of the source depth and the frequency on the spectral excitation of the normal modes if numerical knowledge of free Love waves is assumed to be known.

Harmonic Wave Propagation in a Periodically Layered, Infinite Elastic Body: Plane Strain, Numerical Results

1980 ◽  
Vol 47 (3) ◽  
pp. 531-537 ◽  
Author(s):  
T. J. Delph ◽  
G. Herrmann ◽  
R. K. Kaul
Keyword(s):  
Wave Propagation ◽  
Plane Strain ◽  
Elastic Body ◽  
Harmonic Wave ◽  
Numerical Results ◽  
Analytical Properties

Numerical results are presented for the dispersion spectrum for harmonic wave propagation in an unbounded, periodically layered elastic body in a state of plane strain. Both real and complex branches are considered. The spectrum is shown to be multiple-valued and quite intricate in detail. Some analytical properties of the Floquet surface are also discussed.

Plane-Strain Surface Waves in a Laminated Composite

1982 ◽  
Vol 49 (4) ◽  
pp. 747-753 ◽  
Author(s):  
G. Herrmann ◽  
M. Hemami
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Surface Waves ◽  
Plane Strain ◽  
Half Space ◽  
Laminated Composite ◽  
Elastic Wave Propagation ◽  
Free Plane ◽  
Layered Half Space

Elastic wave propagation in plane strain in a periodically layered half space is considered, with the layering parallel to the bounding traction-free plane. Attention is focused on surface waves of the Rayleigh-type propagating parallel to the bounding plane. It is found that such waves are highly dispersive and that higher branches may be discontinuous.

On a technique for deriving explicit transfer matrices of orthotropic layers

2015 ◽  
Vol 37 (4) ◽  
pp. 303-315 ◽  
Author(s):  
Pham Chi Vinh ◽  
Nguyen Thi Khanh Linh ◽  
Vu Thi Ngoc Anh
Keyword(s):  
Wave Propagation ◽  
Explicit Form ◽  
Half Space ◽  
Transfer Matrix ◽  
Rayleigh Waves ◽  
Secular Equation ◽  
Transfer Matrices ◽  
Orthotropic Layer ◽  
Wave Propagation Problem ◽  
Arbitrary Thickness

This paper presents  a technique by which the transfer matrix in explicit form of an orthotropic layer can be easily obtained. This transfer matrix is applicable for both the wave propagation problem and the reflection/transmission problem. The obtained transfer matrix is then employed to derive the explicit secular equation of Rayleigh waves propagating in an orthotropic half-space coated by an orthotropic layer of arbitrary thickness.

Sign in / Sign up

Export Citation Format

Share Document