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1.
The effect of contact between the sides of a rectilinear crack in the planeR
2={x: x3=0} on the characteristics of the fallure mechanics is studied for the case in which the crack is affected by harmonic tensile-compression
waves and shifts. The surfaces of the crack may assume any orientation relative to the direction of propagation of the waves.
The presence of friction in the zone of contact of the sides of the crack is taken into account. The method of solving the
problem stated is iterative in nature and is based on the solution of a sequence of boundary integral equations for the Fourier
coefficients of the displacement discontinuity vector and the contact force vector. It is also corrected at each step of the
solution so as to satisfy one-sided restrictions in the zone of contact.
Kharkov Highway Technical Institute, Ukraine. Translated from Prikladnaya Mekhanika, Vol. 35, No. 2, pp. 70–75, February,
1999. 相似文献
2.
Ralf Müller Petia Dineva Tsviatko Rangelov Dietmar Gross 《Archive of Applied Mechanics (Ingenieur Archiv)》2012,82(1):97-110
The anti-plane dynamic problem of a functionally graded piezoelectric plane containing a hole–crack system is treated by a
non-hypersingular traction-based boundary integral equation method. The material parameters vary exponentially in the same
manner in an arbitrary direction. The system is loaded by an incident SH-type wave, and impermeable boundary conditions are
assumed. Using a frequency-dependent fundamental solution of the wave equation, the boundary value problem is transformed
into a system of integro-differential equations along the boundary of the hole and on the crack line. Its numerical solution
yields the dynamic stress intensity factors and stress concentration factors. A parametric study reveals their dependence
on the hole–crack scenario and its geometry, characteristics of the dynamic load and magnitude and direction of material inhomogeneity. 相似文献
3.
The plane-stress state of a cracked continuous medium in tension is determined using relaxation elements. The stress state
is analyzed at the tip of a crack surrounded by a plastically deformed material as a band of localized plastic deformation
(LPD) shaped like an elongated ellipse. The plastic deformation considerably decreases the stress concentration at the crack tip.
As the localization of the plastic deformation increases, the stresses at the crack sides decrease to zero. The decrease in
stresses at the tip is accompanied by an increase in the concentration and gradients of the stresses at the end of theLPD band. Here the region of perturbation of the stress field is comparable with the width of the band.
Institute of Physics of Strength and Materials Science, Tomsk 634055. Translated from Prikladnaya Mekhanika i Tekhnicheskaya
Fizika, Vol. 39, No. 6, pp. 132–141, November–December, 1998. 相似文献
4.
V. V. Mykhas’kiv N. D. Grilitskii I. O. Butrak 《Journal of Applied Mechanics and Technical Physics》2006,47(4):556-563
A three-dimensional wave field formed owing to diffraction of low-frequency waves on a curved crack in an infinite elastic
solid at a large distance from the defect is studied by the method of boundary integral equations. Direction diagrams of the
scattered field versus the excentricity of the crack surface and wavenumber are obtained for different directions of incidence
of planar longitudinal waves onto a gently sloping spheroidal crack.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 4, pp. 115–123, July–August, 2006. 相似文献
5.
E. V. Mamontov 《Journal of Applied Mechanics and Technical Physics》1999,40(2):232-237
Invariant submodels of rank two of systems of gas-dynamic equations with a general equation of state are described. All submodels
(26 representatives) are divided into two, classes—evolutionary and stationary. New relations and independent variables and
the coefficients and right sides of the corresponding systems of equations are given.
Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 2, pp. 50–55, March–April, 1999. 相似文献
6.
This paper is concerned with dynamic problems in fracture mechanics for elastic solids having cracks with contacting faces.
The contact problem for a penny-shaped crack with a nonzero initial opening under normally incident harmonic wave is solved
by the method of boundary integral equations. The solutions are compared with those that neglect the contact interaction of
the crack faces. Results are presented for different values of the initial crack opening
Presented at the 6th International Conference on Modern Practice in Stress and Vibration Analysis (Bath, United Kingdom, September
5–7, 2006).
Published in Prikladnaya Mekhanika, Vol. 43, No. 7, pp. 125–131, July 2007. 相似文献
7.
A. A. Koz’ma 《Nonlinear Oscillations》2006,9(4):478-489
We find asymptotic representations for solutions of second-order differential equations whose right-hand sides contain a sum
of terms with nonlinearities of more general form than nonlinearities of the Emden-Fowler type.
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Translated from Neliniini Kolyvannya, Vol. 9, No. 4, pp. 490–501, October–December, 2006. 相似文献
8.
We consider the Navier–Stokes equations in a thin domain of which the top and bottom surfaces are not flat. The velocity fields
are subject to the Navier conditions on those boundaries and the periodicity condition on the other sides of the domain. This
toy model arises from studies of climate and oceanic flows. We show that the strong solutions exist for all time provided
the initial data belong to a “large” set in the Sobolev space H
1. Furthermore we show, for both the autonomous and the nonautonomous problems, the existence of a global attractor for the
class of all strong solutions. This attractor is proved to be also the global attractor for the Leray–Hopf weak solutions
of the Navier–Stokes equations. One issue that arises here is a nontrivial contribution due to the boundary terms. We show
how the boundary conditions imposed on the velocity fields affect the estimates of the Stokes operator and the (nonlinear)
inertial term in the Navier–Stokes equations. This results in a new estimate of the trilinear term, which in turn permits
a short and simple proof of the existence of strong solutions for all time. 相似文献
9.
This paper studies the mode III crack problem of two bonded functionally graded piezoelectric half planes which contain a
crack respectively. These two cracks are located normal to the interface. All the material properties are assumed to vary
along the direction of the crack line. A system of singular integral equations for electrically impermeable and permeable
cracks is derived and solved numerically by using the Gauss–Chebyshev integration formula. The influence of the nonhomogeneous
parameters and the dependence of the crack interactions on the stress and electric displacement intensity factors are investigated. 相似文献
10.
A system of boundary integral equations that allows evaluating the displacement and stress fields for an interfacial crack
under harmonic loading is presented. Expressions for the integral kernels are obtained. A numerical solution for a penny-shaped
crack between steel and aluminum half-spaces under normally incident compression-rarefaction wave is given
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 8, pp. 47–56, July 2007. 相似文献
11.
G. V. Gavrilov 《International Applied Mechanics》2007,43(8):903-911
The subcritical growth of a mode I crack with nonsmall end zones in an aging viscoelastic plate under tensile loads applied
at infinity is studied assuming that the fracture process zone is of constant length. The equations of incubation, transition,
and major crack growth stages are obtained on the basis of the Volterra principle and critical crack opening criterion. The
crack subcritical growth of a specific material is studied as an example
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 8, pp. 92–101, August 2007. 相似文献
12.
The paper studies the subcritical stable growth of a penny-shaped mode I crack in an aging linear viscoelastic body with cylindrical
anisotropy under tensile loads applied at infinity. The equations of quasistatic crack growth are derived using the Volterra
principle for a modified Dugdale model and the critical crack opening displacement as a failure criterion. The kernel of the
operator that describes the viscoelastic crack opening is found using operator-valued continued fractions. As an example,
the subcritical stable growth of a crack in a specific material is studied numerically
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 1, pp. 82–92, January 2007. 相似文献
13.
The Dugdale crack model is generalized to the case of plane strain. The governing equations are set up to determine the stresses
in the plastic zone. Numerical results from specific problems are analyzed and compared with those for plane stress state
and other cases. A relationship between the crack model and K
I-T theory is established in the case of small-scale yielding at the crack tip
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Translated from Prikladnaya Mekhanika, Vol. 41, No. 6, pp. 44–55, June 2005. 相似文献
14.
A. P. Shabanov 《Journal of Applied Mechanics and Technical Physics》2009,50(4):684-690
A model for crack growth is proposed based on studies of the variation in the curvature radius at the crack tip during cyclic
loading. Relations are obtained between mechanical material characteristics, crack geometry, and the rate of crack growth
in a structure under cyclic loading.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 4, pp. 167–175, July–August, 2009. 相似文献
15.
Angelo Marcello Tarantino 《Journal of Elasticity》1999,57(2):85-103
The motion field surrounding a rapidly propagating crack, loaded symmetrically about the plane of the crack, is investigated.
The problem is formulated within the framework of finite elastodynamics for thin slabs composed of compressible hyperelastic
material. Writing the motion equations, the initial and the internal boundary conditions, with respect to a coordinate system
that translates with the moving crack tip, we perform an asymptotic local analysis for a traction-free straight crack that
suddenly grows at constant velocity. Moreover, the asymptotic Piola–Kirchhoff and Cauchy stress fields are computed, and we
discuss the order of singularity of the dynamic stresses.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
G. V. Gavrilov 《International Applied Mechanics》2010,46(4):422-428
The paper addresses subcritical growth of a crack in a thin isotropic plate made of an aging viscoelastic material with time-dependent
elastic modulus. The behavior of the material is described by Arutyunyan’s creep theory. To simulate fracture, a modified
Leonov–Panasyuk–Dugdale model and a critical crack opening displacement criterion are used. An equation describing the subcritical
growth of the crack is derived assuming that Poisson’s ratio is constant. As an example, the critical loads are determined,
and curves of subcritical crack growth are plotted for a specific material. The results are compared with the case of constant
elastic modulus 相似文献
17.
I. I. Mykhailova O. V. Menshykov I. A. Guz 《Archive of Applied Mechanics (Ingenieur Archiv)》2011,81(9):1215-1230
In this paper, the problem of two equal coplanar cracks with allowance for the crack faces contact interaction was investigated.
The problem of the cracks located in homogeneous, isotropic, and linearly elastic solid subjected to normally incident tension–compression
wave is solved by the boundary integral equations method. The influence of the distance between two cracks on the stress intensity
factors (opening mode and transverse shear mode) is studied for a range of wave numbers. The results are compared with those
obtained neglecting cracks’ closure. 相似文献
18.
Effects of Chemical Reaction and Double Dispersion on Non-Darcy Free Convection Heat and Mass Transfer 总被引:1,自引:0,他引:1
In this article, the effects of chemical reaction and double dispersion on non-Darcy free convection heat and mass transfer
from semi-infinite, impermeable vertical wall in a fluid saturated porous medium are investigated. The Forchheimer extension
(non-Darcy term) is considered in the flow equations, while the chemical reaction power–law term is considered in the concentration
equation. The first order chemical reaction (n = 1) was used as an example of calculations. The Darcy and non-Darcy flow, temperature and concentration fields in this study
are observed to be governed by complex interactions among dispersion and natural convection mechanisms. The governing set
of partial differential equations were non-dimensionalized and reduced to a set of ordinary differential equations for which
Runge–Kutta-based numerical technique were implemented. Numerical results for the detail of the velocity, temperature, and
concentration profiles as well as heat transfer rates (Nusselt number) and mass transfer rates (Sherwood number) are presented
in graphs. 相似文献
19.
L. P. Khoroshun 《International Applied Mechanics》2011,46(11):1238-1252
The plane problem for a cracked body with a piecewise-linear stress–strain diagram under tension is reduced by the Fourier
transformation to a system of nonlinear algebraic equations. The system is numerically solved for plane strain and stress
states of a perfect elastoplastic material to study plastic zones, stress and strain distributions, and displacements of crack
faces 相似文献
20.
The growth of a straight mode II crack in a viscoelastic orthotropic plate is examined. The plate material is modeled by a
viscoelastic anisotropic medium. The shear displacement in the fracture process zone is determined as a function of time using
the corresponding elastic solution, the Volterra principle, and the method of operator continued functions. The time dependence
of the crack length is constructed as integral equations of three phases of stable growth. The solution of these equations
gives kinetic curves
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 9, pp. 89–97, September 2006. 相似文献