共查询到20条相似文献,搜索用时 15 毫秒
1.
The paper deals with 3D dynamic response of an elastic half-space loaded by a point force moving at a constant speed along a straight line on the surface. The problem is formulated within the framework of the asymptotic hyperbolic–elliptic model developed earlier by two of the authors. The validity of the model is restricted to the range of speeds close to the Rayleigh wave speed. Steady-state near-field solutions are derived in terms of elementary functions. Transient analysis of surface motion illustrates peculiarities of the resonance associated with the Rayleigh wave. 相似文献
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T. M. Atanackovic R. B. Maretic J. M. Milidragovic 《Archive of Applied Mechanics (Ingenieur Archiv)》1999,69(2):94-104
Summary Stability of a heavy elastic column loaded by a concentrated force at the top is analysed. It is assumed that the column
is fixed to a rigid circular plate that is positioned on a homogeneous, isotropic, linearly elastic half-space. The constitutive
equations for the column are assumed in the form that allows axial compressibility and takes into account the influence of
shear stresses. It is shown that eigenvalues of the linearized equations determine the bifurcation points of the full non-linear
system of equilibrium equations. Also, the type of bifurcation at the lowest eigenvalue is examined and shown that it could
be both super-and sub-critical. The post-critical shape of the column is determined by numerical integration of the equilibrium
equations.
Received 13 June 1998; accepted for publication 12 November 1998 相似文献
4.
A rigid inclusion in an elastic space under the action of a uniform heat flow in the inclusion plane
A. Kaczyński B. Monastyrskyy 《International Journal of Solids and Structures》2013,50(16-17):2631-2640
A solution is presented for the three dimensional static thermoelastic problem of an absolutely rigid inclusion (anticrack) in the case when a uniform heat flow is directed along the inclusion plane. By using the potential method and the Fourier transform technique, the problem is reduced to a system of coupled two-dimensional singular integral equations for the shear stress jumps across the inclusion. As an illustration, a typical application to the circular anticrack is presented. Explicit expressions for the thermal stresses in the inclusion plane are obtained and discussed from the point of view of material failure. 相似文献
5.
I.IntroductionManypracticalproblemsinengineering,suchascompositematerial,weldedjointorribbedslab,needustostudytheinteractionproblemoflineinclusionandcircularinclusionasshowninFig.1.Sotheproblemwasdiscussedinthispaper.Proceedingfromthestressfieldofplanecon… 相似文献
6.
İsa Çömez 《International Journal of Solids and Structures》2010,47(7-8):1090-1097
The frictional contact problem for a layer resting on a homogeneous half plane is handled using linear elasticity theory in this study. The layer is in contact with a rigid cylindrical stamp that is on the layer and applies a concentrated force in the normal and tangential directions. Friction between the component couples of layer–stamp and layer–half plane is taken into account. The problem is reduced to a system of singular integral equations, in which the contact pressures and the contact areas are the unknowns, and it is treated using Fourier transforms and the boundary conditions for the problem. The system of singular integral equations is solved numerically using the Gauss–Jacobi integration formula with equilibrium and consistency conditions. Numerical results for the contact pressures and the contact areas are given as a solution for both the frictional and the frictionless cases. This work is the first study that investigates the effect of friction on the receding contact problem of a layer and a half plane with two contact areas. 相似文献
7.
A. G. Akopyan 《Journal of Applied Mechanics and Technical Physics》1991,32(5):808-813
Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 5, pp. 159–163, September–October, 1991. 相似文献
8.
云天铨 《应用数学和力学(英文版)》1988,9(5):449-453
The axially symmetric torsion of rigid circular shaft of varying diameter embedded in an elastic half space is studied by
line-loaded integral equation method (LLIEM), where the problem is formulated by distributions of ficitious fundamental loads
PRCHS (point ring couple in half space) along the axis of symmetry in interval of the shaft and is reduced to a one-dimensional
and non-singular Fredholm integral equation of the first kind and is easily solved numerically. Numerical examples of torsin
of rigid conic, cylinder, conical-cylinder embedded in an elastic half space are given and compared with the known result
obtained by the others. The exact solution of torsion of rigid half sphere embedded in an elastic half space is also presented.
Project Supported by the National Science Foundation of China. 相似文献
9.
The present paper deals with the problem of load transfer from elastic inclusions to an infinite elastic orthotropic plane with cuts located on one of the principal orthotropy directions. The constitutive system of equations of this problem is derived under the assumption that the inclusions are in a uniaxial stress state. The obtained system consists of a singular integro-differential equation and a singular integral equation for the jumps of the tangential stresses acting on the inclusion shores and for the derivative of the the cut opening function. The behavior of solutions of the system of constitutive equations at the endpoints of the inclusions and cuts is studied, and the solution of this system is constructed by the numerical-analytic discrete singularity method. 相似文献
10.
Andrzej Kaczy´nski Wojciech Kozłowski 《International Journal of Solids and Structures》2009,46(7-8):1772-1777
This paper examines the three-dimensional problem of finding thermal stresses due to an insulated rigid sheet-like inclusion (anticrack) in an elastic space under a uniform perpendicular heat flow. By using appropriate harmonic potentials, a general method of solving this problem is presented. The resulting boundary-value problems are reduced to classical mixed problems of potential theory. For the purpose of illustration, a complete solution in terms of elementary functions for a rigid circularly shaped inclusion is given and discussed from the point of view of material failure. 相似文献
11.
I. I. Argatov 《Journal of Applied Mechanics and Technical Physics》2008,49(1):98-104
An asymptotic model for deformation of an elastic space with a rigid thin reinforcing bar is constructed. The elastic modulus
of the fiber far exceeds the elastic modulus of the matrix. The shape optimization problem for the reinforcing bar is solved
on the basis of the uniform strength condition.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 1, pp. 120–128, January–February, 2008. 相似文献
12.
Spheroidal rigid inclusion in an elastic medium under torsion 总被引:1,自引:0,他引:1
The displacement field is determined when a rigid spheroidal inclusion is present in an infinite, isotropic and homogeneous elastic medium under torsion. The values of the force and moment are derived. The solutions for the limiting cases of a sphere and a circular disk are also presented. The analysis is based on suitable distributions of singularities on the axis of symmetry of the inclusion. 相似文献
13.
M. L. Ghosh 《Applied Scientific Research》1965,14(1):31-42
Summary A rigid circular disc is attached to the surface of an isotropic elastic half space. A twisting moment in the form of Pr (t) where P is a constant and (t) is the dirac-delta function is applied to the disc. Following Cagniard and Dix the exact evaluation of the displacement at any point in the medium has been made. 相似文献
14.
Watanabe Kazumi 《International Journal of Solids and Structures》1977,13(1):63-74
The well-known Cagniard's technique seems very useful for analyzing the transient problem of an elastic body subjected to a moving load with uniform velocity, but, in the cases of non-uniform velocity it would be difficult to apply the technique directly to analyze the problem. For such cases, instead of the technique, the convolution theorem of the Laplace transform or the dynamic Betti-Rayleigh reciprocal theorem has been applied usefully by many authors.In this paper, an inversion scheme which enables us to apply the Cagniard's technique directly to those difficult problems is presented by solving the problem of a reciprocating anti-plane shear load applied to a layered elastic half space. In this treatment it will be found clearly that our technique is simpler and more systematic than any other techniques for solving the problem. Numerical results are shown in the form of curves and the wave-front singularities are also investigated. 相似文献
15.
《Wave Motion》2020
Cloaking of a circular cylindrical elastic inclusion embedded in a homogeneous linear isotropic elastic medium from antiplane elastic waves is studied. The transformation or change-of-variables method is used to determine the material properties of the cloak and the homogenization theory of composites is used to construct a multilayered cloak consisting of many bi-material cells. The large system of algebraic equations associated with this problem is solved by using the concept of multiple scattering with wave expansion coefficient matrices. Numerical results for cloaking of an elastic inclusion and a rigid inclusion are compared with the case of a cavity. It is found that while the cloaking patterns for the three cases are similar, the major difference is that standing waves are generated in the elastic inclusion and the multilayered cloak cannot prevent the motion inside the elastic inclusion, even though the cloak seems nearly perfect. Waves can penetrate into and cause vibrations inside the elastic inclusion, where the amplitude of standing waves depend on the material properties of the inclusion but are very much reduced when compared to the case when there is no cloak. For a prescribed mass density, the displacements inside the elastic cylinder decrease as the shear modulus increases. Moreover, the cloaking of the elastic inclusion over a range of wavenumbers is also investigated. There is significant low frequency scattering even if the cloak consists of a large number of layers. When the wavenumber increases, the multilayered cloak is not effective if the cloak consists of an insufficient number of layers. Resonance effects that occur in cloaking of elastic inclusions are also discussed. 相似文献
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H.H. Jabali 《International Journal of Solids and Structures》1975,11(11):1219-1221
The static solution to the problem of a layer bonded to an elastic half-space, where the layer is driven by the torsional rotation of a bonded rigid circular disk, is considered here. An iterative solution, perturbing on that given for the elastic half-space, is obtained as a convergent power series, provided the ratio of the stratum depth to the radius of the disk is large. An equation for the applied static torque at the surface of the rigid disk is also calculated and compared, under limiting cases, with known results. 相似文献
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Here we carry out a systematic parametric study of a uniform cylindrical missile impacting rigid or elastic structures. We give an analytical result for the impact force in case of rigid target. A new parameter, the damage potential is introduced and it is shown that this single dimensionless combination of the parameters describes the course of the impact in this simplest case. For elastic target structures, we also show numerically that the course of the reaction force, the maximum target displacement and the duration of the impact depend primarily on the same dimensionless parameter with a secondary effect of the missile to target mass ratio and the relative stiffness of the target. The rigid target assumption is not always conservative with regard to the reaction force due to target vibration. We find a resonant effect in the maximum target displacement as the function of the missile to target mass ratio. The motivation of our work is rooted in the investigation of aircraft fuselage impact into robust structures like the containment of a nuclear power plant. 相似文献
20.
E. E. Gdoutos D. A. Eftaxiopoulos M. A. Kattis 《Theoretical and Applied Fracture Mechanics》1987,8(3)
The two-dimensional problem of a rigid rounded-off angle triangular inclusion partially bonded in an infinite elastic plate is studied. The unbonded part of the inclusion boundary forms an interfacial crack. Based on the complex variable method for curvilinear boundaries, the problem is reduced to a non-homogeneous Hilbert problem and the stress and displacement fields in the plate are obtained in closed form. Special attention is paid in the investigation of the stress field in the vicinity of the crack tip. It is found that the stresses present an oscillatory singularity and the general equations for the local stresses are derived. The singular stress field is coupled with the maximum circumferential stress and the minimum strain energy density criteria to study the fracture characteristics of the composite plate. Results are given for the complex stress intensity factors, the local stresses, the crack extension angles and the critical applied loads for unstable crack growth from its more vulnerable tip or two types of interfacial cracks along the inclusion boundary. 相似文献