Three-Dimensional Vibrations of a Beam on an Elastic Half-Space: Resonance Interaction of Vertical-Longitudinal and Lateral Beam Waves

1997 ◽  
Vol 64 (4) ◽  
pp. 951-956 ◽  
Author(s):  
A. V. Metrikine ◽  
H. A. Dieterman
Keyword(s):  
Half Space ◽  
Three Dimensional ◽  
Elastic Half Space ◽  
Finite Width ◽  
Lateral Bending ◽  
Beam Asymmetry ◽  
Lateral Vibrations ◽  
Vertical Vibrations ◽  
Euler Bernoulli Beam ◽  
Crossing Point

Three-dimensional vibrations of a Euler-Bernoulli beam on an elastic half-space are investigated. In the model the beam has a finite width and the half-space and beam deflections are equal along the centre line of the beam. It is shown that the vertical and longitudinal beam vibrations are uncoupled from the lateral ones. The dispersion relations for the lateral and vertical-longitudinal waves in the beam are derived and the respective dispersion curves are plotted. These curves can cross each other due to the different equivalent stiffnesses of the half-space in vertical and lateral directions and different vertical and lateral bending stiffnesses of the beam. The existence of a crossing point implies that if the vertical-longitudinal and lateral beam vibrations are coupled for some reason (half-space inhomogeneity, beam asymmetry, etc.), the energy of the vertical vibrations of the beam can be resonantly transferred into the energy of lateral vibrations. This transfer will take place if the frequency of vibrations is close to the frequency determined by the crossing point. The dependency of the frequency of the crossing point on axial compressional stresses in the beam is studied. It is shown that this frequency decreases as the stresses increase.

Steady-state response of an elastic half-space to a moving dislocation of finite width

1983 ◽  
Vol 73 (1) ◽  
pp. 1-22
Author(s):  
J. Enrique Luco ◽  
John G. Anderson
Keyword(s):  
Half Space ◽  
Near Field ◽  
Three Dimensional ◽  
Elastic Half Space ◽  
Numerical Results ◽  
Finite Width ◽  
Slip Vector ◽  
State Response ◽  
Three Dimensional Models ◽  
Fault Length

abstract An analytical method to evaluate the transient response on the surface of an elastic half-space for a kinematic dislocation over an infinitely long fault of finite width and arbitrary dip is presented. The model includes finite rupture velocities in the direction of both the strike and dip of the fault. In this sense, it differs from previous two- and three-dimensional models which typically assume one of these velocities to be infinite. In addition to the effects of the free boundary, the model considers a slip vector in an arbitrary direction. The assumptions of infinite fault length and uniform rupture velocities account for the relative simplicity of the solution which is invariant to an observer moving along the strike of the fault with a speed equal to the rupture velocity. These assumptions limit the applicability of the solution to near-field locations far from the ends of realistic faults. A limited set of numerical results illustrating the types of pulse shapes obtained by use of this model, and, some tests to validate the derivation and the numerical results are presented.

Guided Surface Waves on an Elastic Half Space

1971 ◽  
Vol 38 (4) ◽  
pp. 899-905 ◽  
Author(s):  
L. B. Freund
Keyword(s):  
Wave Propagation ◽  
Surface Wave ◽  
Surface Waves ◽  
Half Space ◽  
Body Wave ◽  
Three Dimensional ◽  
Elastic Half Space ◽  
Normal Displacement ◽  
Rigid Barrier ◽  
Wave Disturbances

Three-dimensional wave propagation in an elastic half space is considered. The half space is traction free on half its boundary, while the remaining part of the boundary is free of shear traction and is constrained against normal displacement by a smooth, rigid barrier. A time-harmonic surface wave, traveling on the traction free part of the surface, is obliquely incident on the edge of the barrier. The amplitude and the phase of the resulting reflected surface wave are determined by means of Laplace transform methods and the Wiener-Hopf technique. Wave propagation in an elastic half space in contact with two rigid, smooth barriers is then considered. The barriers are arranged so that a strip on the surface of uniform width is traction free, which forms a wave guide for surface waves. Results of the surface wave reflection problem are then used to geometrically construct dispersion relations for the propagation of unattenuated guided surface waves in the guiding structure. The rate of decay of body wave disturbances, localized near the edges of the guide, is discussed.

Contact Stress Analysis of a Layered Transversely Isotropic Half-Space

1992 ◽  
Vol 114 (2) ◽  
pp. 253-261 ◽  
Author(s):  
C. H. Kuo ◽  
L. M. Keer
Keyword(s):  
Half Space ◽  
Mixed Boundary ◽  
Contact Region ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Hankel Transform ◽  
Elastic Half Space ◽  
Contact Stresses ◽  
Stress Components ◽  
Contact Failure

The three-dimensional problem of contact between a spherical indenter and a multi-layered structure bonded to an elastic half-space is investigated. The layers and half-space are assumed to be composed of transversely isotropic materials. By the use of Hankel transforms, the mixed boundary value problem is reduced to an integral equation, which is solved numerically to determine the contact stresses and contact region. The interior displacement and stress fields in both the layer and half-space can be calculated from the inverse Hankel transform used with the solved contact stresses prescribed over the contact region. The stress components, which may be related to the contact failure of coatings, are discussed for various coating thicknesses.

Transient Thermoelastic Stress Fields in a Half-Space

2002 ◽  
Vol 125 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Shuangbiao Liu ◽  
Qian Wang
Keyword(s):  
Stress Field ◽  
Half Space ◽  
Frictional Heating ◽  
Three Dimensional ◽  
Thermoelastic Stress ◽  
Parabolic Type ◽  
Elastic Half Space ◽  
Transform Method ◽  
Rough Surface Contact ◽  
Thermoelastic Stress Field

Computing the thermoelastic stress field of a material subjected to frictional heating is essential for component failure prevention and life prediction. However, the analysis for three-dimensional thermoelastic stress field for tribological problems is not well developed. Furthermore, the pressure distribution due to rough surface contact is irregular; hence the frictional heating can hardly be described by an analytical expression. This paper presents a novel set of frequency-domain expressions (frequency response functions) of the thermoelastic stress field of a uniformly moving three-dimensional elastic half-space subjected to arbitrary transient frictional heating, where the velocity of the half-space, its magnitude and direction, can be an arbitrary function of time. General formulas are expressed in the form of time integrals, and important expressions for constant velocities are given for the transient-instantaneous, transient-continuous, and steady-state cases. The thermoelastic stress field inside a translating half-space with constant velocities are illustrated and discussed by using the discrete convolution and fast Fourier transform method when a parabolic type or an irregularly distributed heat source is applied.

The Transition Matrix Formalism for the Scattering of an Alluvium on an Elastic Half-Space

2007 ◽  
Author(s):  
Wen-I Liao ◽  
Tsung-Jen Teng ◽  
Shiang-Jung Wang
Keyword(s):  
Half Space ◽  
Transition Matrix ◽  
Plane Waves ◽  
Three Dimensional ◽  
Scattering Matrix ◽  
Elastic Half Space ◽  
Basis Functions ◽  
Matrix Formalism ◽  
T Matrix ◽  
Singular Wave

This paper develops the transition matrix formalism for scattering from an three-dimensional alluvium on an elastic half-space. Betti’s third identity is employed to establish orthogonality conditions among basis functions that are Lamb’s singular wave functions. The total displacements and associated tractions exterior and interior to the surface are expanded in a Rayleigh series. The boundary conditions are applied and the T-matrix is derived. A linear transformation is utilized to construct a set of orthogonal basis functions. The transformed T-matrix is related to the scattering matrix and it is shown that the scattering matrix is symmetric and unitary and that the T-matrix is symmetric. Typical numerical results obtained by incident plane waves for verification are presented.

Viscous-Elastic Half-Space Vibration Stimulated by High-Speed Moving Loads of Different Speeds

2012 ◽  
Vol 518-523 ◽  
pp. 3874-3877
Author(s):  
Tao Qian ◽  
Xiao Ping Shui ◽  
Yong Fa Zhang ◽  
Yong Gang Guo ◽  
Meng Ma
Keyword(s):  
Half Space ◽  
Coordinate Transformation ◽  
High Speed ◽  
Three Dimensional ◽  
Elastic Half Space ◽  
Moving Loads ◽  
Cylindrical Coordinates ◽  
Relative Coordinate ◽  
The Laplace Transform ◽  
Practical Security

A rule of response of an infinite viscous-elastic half-space stimulated by the moving loads of different speeds is outlined in this paper. In order to obtain a three-dimensional analytical solution of the Viscous-elastic half-space with the moving loads of different speeds, the Laplace transform and relative coordinate transformation in cylindrical coordinates are used. Then, the IFFT and relative coordinate transformation are used to solve two-dimensional infinite integration which can greatly improve the operational efficiency. The rules of responses of different velocities from the results by using the principle of dynamics and energy dissipation are also analyzed and induced in this paper, and obtain the incentives of displacement distortion by the super-Rayleigh wave velocity at surface. The results could be referred in improving the practical security in the project.

THREE-DIMENSIONAL SURFACE CRACK ANALYSIS OF ELASTIC HALF-SPACE UNDER ROLLING CONTACT LOAD

2009 ◽  
Vol 06 (02) ◽  
pp. 317-332 ◽  
Author(s):  
MENG-CHENG CHEN ◽  
HUI-QIN YU
Keyword(s):  
Numerical Solution ◽  
Integral Equations ◽  
Half Space ◽  
Three Dimensional ◽  
Elastic Half Space ◽  
Rolling Contact ◽  
Contact Load ◽  
Hypersingular Integral ◽  
Space Body ◽  
Planar Crack

In this work a three-dimensional planar crack on the surface of elastic half-space was analyzed under rolling contact load. The stresses interior to an elastic half-space body under rolling contact load and those produced by an infinitesimal displacement jump loop for the elastic half-space body were used to reduce the planar crack problem to the solution of a system of two-dimensional hypersingular integral equations with unknown displacement jump. The ideas of finite element discretization were employed to construct numerical solution schemes for solving the integral equations. An appropriate treatment of the associated hypersingular integral in the numerical solution to the integral equations was proposed in Hadamard's finite-part integral sense. The numerical results showed that the present procedure yields solutions with high accuracies. The stress intensity factors near the crack front edge under rolling contact load were indicated in graphical form with varying the crack shape, the radius of rolling contact zone and the friction coefficients, respectively. In addition, the influence of the lubricant infiltrating the crack surfaces on the crack propagation was also discussed in the paper.

The Effect of an Axial Force on the Response of an Anisotropic Elastic Half Space to a Rolling Cylinder

1973 ◽  
Vol 40 (1) ◽  
pp. 251-256 ◽  
Author(s):  
D. L. Clements
Keyword(s):  
Half Space ◽  
Axial Force ◽  
Elastic Half Space ◽  
Applied Force ◽  
Finite Width ◽  
Infinite Length ◽  
Anisotropic Elastic

The problem of an inflated cylindrical tire of infinite length and constant finite width steadily rolling over the surface of an anisotropic elastic half space is examined. The influence of an applied force, acting along the axis of the cylinder, on the width of the region of slip at each end of the tire is determined. In particular, it is shown numerically that when a material exhibits certain anisotropy the presence of an axial force can considerably reduce the width of the zones of slip.

Bond of tube in semi-infinite elastic solid

1980 ◽  
Vol 15 (2) ◽  
pp. 53-62 ◽  
Author(s):  
J W Ivering
Keyword(s):  
Half Space ◽  
Three Dimensional ◽  
Elastic Solid ◽  
Elastic Half Space ◽  
Infinite Medium ◽  
Bond Stress ◽  
Elastic Analysis ◽  
One Dimensional ◽  
Stress Curve ◽  
Tube Segment

The analysis of the bond stress of a thick-walled tube embedded at the surface of an elastic, isotropic, semi-infinite medium is presented. The condition of three-dimensional compatibility between the tube and the anchorage medium is taken into account. An equilibrium equation for a segment of an embedded tube is derived, from which bond stresses acting on the tube can be computed. The general solution obtained relates to the vector function for a uniform lineal load acting perpendicularly to the surface of an elastic half-space. The solution is in agreement with equations derived independently for cases of one-dimensional (lineal) compatibility. The equation of equilibrium derived for a tube segment embedded at the surface of an elastic half-space is transformed to a form suitable for solving the bond stresses of a tube anchorage embedded at some distance from the surface. A numerical solution of bond stresses obtained by elastic analysis is compared to the bond stress curve along the anchorage obtained experimentally.

Coupled Rocking and Lateral Vibrations of Embedded Footings

1973 ◽  
Vol 10 (2) ◽  
pp. 145-160 ◽  
Author(s):  
C. M. Urlich ◽  
R. L. Kuhlemeyer
Keyword(s):  
Steady State ◽  
Numerical Model ◽  
Half Space ◽  
Good Accuracy ◽  
Elastic Half Space ◽  
Spring Constant ◽  
Lateral Vibrations

A numerical model is described that was utilized to solve the problem of steady state coupled rocking and lateral vibrations of footings embedded into an elastic half space. The good accuracy of the model is confirmed by comparing results obtained for footings founded on the surface of the half space with corresponding results obtained by Veletsos and Wei (J. Soil Mech. Found. Div. Am. Soc. Civ. Eng. 97, pp. 1227–1249, 1971). The results indicate that embedded footings behave dynamically in a manner that cannot be properly predicted by the use of an appropriate embedded footing static spring constant in conjunction with displacement functions obtained for surface footings.

Sign in / Sign up

Export Citation Format

Share Document