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1.
Summary In the present paper, the wave propagation from a cylindrical cavity in an infinite medium exhibiting couple-stress is considered. The variations of Hoop-stress on the cavity surface are investigated for different couple-stress material moduli and wave lengths. Significant differences are found when compared with those based on classical theory of elasticity. 相似文献
2.
Jayanta Bhattacharya 《Pure and Applied Geophysics》1969,73(1):93-98
Summary The propagation of a certain type of surface waves in a non-homogeneous elastic layer of finite thickness lying in welded contact with a semi-infinite homogeneous elastic medium has been investigated in this paper. The surface wave is characterised by the fact that the dilatation and the vertical displacement component are both zero. It has been proved that such disturbance can propagate only when the phase velocity of the wave is greater than the shear wave velocity and the group velocity is inversely proportional to the phase velocity. 相似文献
3.
Saurendra Nath De 《Pure and Applied Geophysics》1972,99(1):55-60
Summary The paper deals with the propagation of waves in a magneto-elastic initially stressed conducting layer. The wave velocity equation obtained is in agreement with the classical result of Rayleigh and Lamb when the layer is initially unstressed and the magnetic field isabsent. 相似文献
4.
分析了小变形情况下变形体的平动变形和转动变形,利用连续介质的动量和动量矩守恒方程,应用各向同性线弹性体的本构关系和偶应力本构关系,提出无限弹性介质中存在体积波(压力波)、旋转波(偶应力波)和偏斜波(偏斜应力波).旋转波和偏斜波均满足形式一致的四阶波动方程,但引起不同的运动学行为和应力状态,四阶旋转波和偏斜波的传播速度不再是依赖材料参数的常值.不计旋转变形时,各向同性弹性固体中只有体积波和二阶偏斜波的传播,这时传播速度均为常数.在3种波动模式中,体积波与传统弹性应力波理论完全一致,四阶偏斜波可退化为二阶偏斜波,但后者不同于传统应力波理论中以位移作为波函数的二阶剪切波.从变形运动学与内力的关系以及能量传播的角度分析了传统应力波理论中关于二阶旋转波和二阶剪切波存在的问题. 相似文献
5.
Jayanta Bhattacharya 《Pure and Applied Geophysics》1969,72(1):61-71
Summary The conditions under which Love type ofSH waves can propagate in a non-homogeneous internal stratum of finite depth lying between two semi-infinite isotropic elastic media are considered in this paper. Two types of non-homogeneity have been studied, in one case the rigidity is supposed to vary exponentially with depth while the density remains constant and in the other both rigidity and density are assumed to vary linearly with depth. 相似文献
6.
Sasadhar De 《Pure and Applied Geophysics》1972,101(1):90-101
Summary This paper deals with the propagation of Love waves in a non-homogeneous isotropic layer of finite depth standing on an infinite non-isotropic layer when there a parabolic irregular zone exists at the interface of the two media. 相似文献
7.
IntroductionItiswellknownthatanisotropylieswidelyintheundergroundmedia.Anisotropicmediawhicharemetintheseismicengineeringandseismicexplorationofenergyaremainlycausedbytheperiodicthinlayers(PTL)andextensivedilatancyanisotropy(EDA).Insuchmedia,anisotropyleadstomorecomplicatepropagationofseismicwave,thesignificantfeatureinanisotropicmediaisvelocityanisotropy.Infact,undergroundstrataareverycomplicated,whichareusuallycomposedofsolidframeandfluid(suchasoil,gasesorwater)inpores.Inordertostudyseism… 相似文献
8.
Giriraj Tiwari 《Pure and Applied Geophysics》1971,91(1):71-75
Summary Displacement due to impulsive twist in a semi-infinite elastic medium is calculated in the light of Cosserats theory of couple stresses [1, 2]. Numerical results are obtained for a particular 相似文献
9.
Sixiong Han Yasuaki Ichikawa Toshikazu Kawamoto 《Soil Dynamics and Earthquake Engineering》1991,10(6)
In this paper, a new model to treat the problem of elastic wave travelling in rock mass that embeds cracks is proposed, in which, instead of modelling the crack directly the mechanical effects of discontinuities are translated into the equivalent nodal forces on a numerical procedure. Thus the response is physically obtained as the superposition of the incident wave field and the scattering wave field produced by the radiation of the reflected waves from the crack surfaces. Finally, a numerical example is carried out and it shows that the results by the proposed method have a very good agreement with those of the exact ones. 相似文献
10.
Summary The present paper is concerned with the transmission of elastic waves through a second-order fluid layer sandwiched between homogeneous elastic media having identical properties. It is concluded that the transmission ratio increases with the increasing absolute values of visco-elastic co-efficient and also with the wavelength of the wave transmitted. 相似文献
11.
Arabinda Biswas 《Pure and Applied Geophysics》1966,64(1):5-8
Summary The present note is devoted to find out the possibility of propagation of love waves in a heterogeneous layer of finite depth lying on a homogenous semi-infinite elastic medium, the rigidity and density in the upper layer varying as (1–sinz), where is a constant andz is the vertical distance from the interface. The numerical results for the phase velocity for some special Earth models are given. 相似文献
12.
Gopinath Sarkar 《Pure and Applied Geophysics》1966,63(1):5-10
Summary The effect of surface irregularities in the form of boundary discontinuous gradients has been studied. It has been shown that certain waves will be attenuated due to passage through such irregularities in internal structure. 相似文献
13.
Abraham Ungar 《Pure and Applied Geophysics》1976,114(5):845-861
The steady-state response is determined of elastic layered media to buried moving normal point loads. The exact solution appears as a superposition of infinitely many rays, each of them given in closed form, in terms of algebraic functions. The solution obtained yields a local behaviour corresponding to the unbounded-space solution. The unbounded-space problem was previously solved byEason, Fulton andSneddon [8] and their solution is utilized for the present solution by superposing it on secondary fields so as to satisfy the boundary conditions. The secondary fields are obtained by the method of the differential transferm described below. 相似文献
14.
The wave field patterns of the propagation of longitudinal and transverse elastic waves in grain-oriented rocks 总被引:1,自引:0,他引:1
A. N. Nikitin T. I. Ivankina V. K. Ignatovich 《Izvestiya Physics of the Solid Earth》2009,45(5):424-436
In the work under consideration, on the basis of data analysis on the velocities of quasi-longitudinal Vp and quasi-transverse Vs waves—measured for rock samples at high pressures and temperatures, and analogous velocities, calculated on the basis of the grain orientation distribution function, reconstructed from the neutron-diffraction textural experiment—the indicative inconsistencies between the experimental and model characteristics were inferred. The theoretical analysis of the wave field patterns of the propagation of longitudinal and transverse elastic waves in the anisotropic media is carried out. It is established that, in the general case, in the anisotropic inhomogeneous media the velocities of Vp and Vs propagation, measured experimentally and obtained from the modeling, cannot coincide due to the existence of the physical coupling between the vibrations of two types: transverse and longitudinal vibrations. 相似文献
15.
16.
M. C. Wadhawan 《Pure and Applied Geophysics》1973,104(1):513-522
Summary In this paper, steady state thermoelastic stresses in an elastic layer when there is a heat flux at one of its bounding planes, have been determined by the method of differential operators and Mittag-Leffler theorem. 相似文献
17.
Mrinal K. Paul 《Pure and Applied Geophysics》1965,62(1):105-117
Summary The effect of slightly curved boundaries (free surfaces and interfaces) of the elastic mediums on the components of displacement of a particle in a medium due to the propagation of the surface waves has been investigated in this paper. It has been found that along with the usual displacement components for stratified boundaries (designated here as primary components), there exist secondary displacement components arising from the presence of curvature in the boundaries. They are constituted of different harmonic components with their amplitudes proportional to the parameters which measure the extent of curvature of the boundaries. The wave numbers of these harmonic constituents are related to those of the primary components in a definite way decided by the shapes of the boundaries. 相似文献
18.
Summary The present note, as its title implies, is concerned with the investigation of disturbances in an infinite elastic medium containing an initial magnetic field in the axial direction. The equations ofMaxwell, those of elasticity have been effectively made use of to solve the problem. 相似文献
19.
Surface wave propagation in fiber-reinforced anisotropic elastic layer between liquid saturated porous half space and uniform liquid layer 总被引:1,自引:1,他引:0
Surface wave propagation in fiber-reinforced anisotropic elastic layer between a liquid saturated porous half space and a
uniform liquid layer is considered. Equation of motion and suitable boundary conditions give rise to a dispersion equation
in the form of a ninth order determinant. Phase velocity and group velocity of a particular model have been studied. 相似文献
20.
Generation of SH-type waves due to shearing stress discontinuity in a sandy layer overlying an isotropic and inhomogeneous elastic half-space 总被引:2,自引:2,他引:0
The generation of SH-type waves due to sudden application of a stress discontinuity which moves after creation at the sandy layer of finite thickness overlying an isotropic and inhomogeneous elastic half-space is considered. The displacements are obtained in exact form by the method due to Cagniard modified by De Hoop. The numerical calculations are obtained. Two cases of shearing stress discontinuities are considered for different sandiness parameters. The graphs are drawn to show the effect of sandiness in the displacement components. 相似文献