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1.
V. V. Glagolev A. A. Markin T. A. Mertsalova 《Journal of Applied Mechanics and Technical Physics》2009,50(1):112-117
A problem of the beginning of motion of a finite-width cut in a linearly elastic plane under the action of symmetric external
loading is formulated. The material on the way of cut propagation forms a layer (interaction layer). The stress-strain state
of the material is postulated to be homogeneous across this layer. A system of integral boundary equations is obtained for
determining the stress-strain state. Based on this system of equations, a discrete model of separation of the layer material
is constructed under the assumption of a constant stress-strain state in an element of the interaction layer. The stress distribution
in the pre-fracture zone is determined.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 1, pp. 134–140, January–February, 2009. 相似文献
2.
A model describing the stress-strain state in the neighborhood of a physical cut with an arbitrary distribution of external load along its faces is presented. The stress-strain state of a material layer bounded by the continuations of the cut faces is considered. The interaction between the layer and the external half-planes leads to a closed system of integrodifferential equations for the mean stress components in the layer, which splits into two equations for the mean normal stresses and an equation for the mean shear stress. Numerical solutions of the system for the cases of symmetric and antisymmetric loading of the faces by concentrated forces are given. Conditions for the transition of the tip region of the cut to the state of plasticity and fracture are considered. 相似文献
3.
M. V. Gavrilkina V. V. Glagolev A. A. Markin 《Journal of Applied Mechanics and Technical Physics》2007,48(4):571-576
This paper considers a model for the opening-mode fracture separation process based on the introduction of an interaction
layer. This layer is defined as the region of localization of the fracture process. The stress-strain state of the layer material
is uniform in the cross section of the layer. A study is made of the deformation of a double-cantilever beam weakened by a
notch whose width is equal to the thickness of the interaction layer. The problem is solved in a linearly geometrical approximation.
The thickness of the interaction layer is estimated, and a method for solving the formulated problem is proposed.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 4, pp. 121–127, July–August, 2007. 相似文献
4.
V. M. Trach 《International Applied Mechanics》2008,44(3):331-344
An approach to solving the buckling problem for shells made of a composite material with one plane of elastic symmetry is
presented. The approach employs complex Fourier series. The prebuckling stress-strain state is assumed to be geometrically
nonlinear. The stability of a cylindrical shell under axial compression and uniform side pressure is analyzed using the Runge-Kutta
method with discrete orthogonalization. The numerical results are compared with analytical solutions
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 3, pp. 109–124, March 2008. 相似文献
5.
《Acta Mechanica Solida Sinica》2015,(4)
A physical cut model is used to describe the changes in the stress-strain state(SSS)in elastoplastic bodies weakened by cracks. The distance between the crack edges is considered to be finite in contrast to the mathematical cut. The interactive layer with a thickness limited by the possibility of using the hypothesis of continuity is distinguished on the physical cut extension.Distribution of stresses and strains over the layer thickness is constant and does not depend on the geometry of the boundary between the cut and the interactive layer. The relationship between stresses and strains is determined by the deformation plasticity theory. The problem of plane strain or plane stress state of an arbitrary finite body weakened by a physical cut is reduced to solving a system of two variational equations for displacement fields in the body parts adjacent to the interactive layer. The proposed approach eliminates the singularity in stress distribution in contrast to the mathematical cut model. Use of local strength criteria allows us to determine the time, point and direction of the fracture initiation. Possibilities of the proposed model are illustrated by solving the problems of determining the SSS of a rectangular body weakened by a physical cut under symmetric and antisymmetric loadings. 相似文献
6.
The problem of determining the stress-strain state of an elastic plane with a physical cut loaded by an antisymmetric system of forces is posed and solved under the condition that the tangential stresses are homogeneous across the thickness of the layer continuing the cut. 相似文献
7.
A finite-element algorithm is proposed for the analysis of the thermoviscoelastoplastic stress-strain state of bodies under
complex loading (thermal and mechanical). It is assumed that an arbitrary element of the body deforms along a rectilinear
or slightly curved path. The three-dimensional stress-strain state of the body’s elements is determined using the iterative
method of additional strains. The technique is tested by analyzing the three-dimensional viscoelastic stress-strain state
of a hollow cylinder and the thermoplastic state of a disk
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 5, pp. 16–25, May 2006. 相似文献
8.
The paper addresses a plane problem: a concentrated force acts on a plate resting on an elastic half-space with homogeneous
prestrain. The equations of motion of the plate incorporate shear and rotary inertia. The half-space is assumed to be incompressible
and isotropic in the natural state. The elastic potential is given in general form and is only specified for numerical purposes.
The dependence of the critical velocity of the load and the stress-strain state on the prestresses is analyzed for different
ratios between the stiffnesses of the layer and half-space and different contact conditions. The calculations are carried
out for a half-space with Bartenev-Khazanovich potential
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 3, pp. 36–54, March 2008. 相似文献
9.
R. G. Terekhov N. N. Tormakhov Yu. N. Shevchenko 《International Applied Mechanics》2000,36(3):343-347
The stress-strain state and fracture of a transversally isotropic material subject to uniaxial compression in a direction
parallel to the isotropy plane is studied. The deformation theory of the plasticity of a transversally isotropic body was
used to analyze the stress-strain state. The fracture analysis of the material is carried out using a proposed variant of
the strain-strength criterion. Theoretical and experimental data on the stress-strain state and the strength of a transversally
isotropic material are compared.
S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev. Translated from Prikladnaya Mekhanika,
Vol. 36, No. 3, pp. 67–71, March, 2000. 相似文献
10.
The structural theory of short-term damage is used to study the coupled processes of deformation and microdamage of a physically
nonlinear material in a combined stress state. The basis for the analysis is the stochastic elasticity equations for a physically
nonlinear porous medium. Damage in a microvolume of the material is assumed to occur in accordance with the Huber-Mises failure
criterion. The balance equation for damaged microvolumes is derived and added to the macrostress-macrostrain relations to
produce a closed-form system of equations. It describes the coupled processes of nonlinear deformation and microdamage of
the porous material. Algorithms are developed for calculating the dependence of microdamage on macrostresses and macrostrains
and plotting stress-strain curves for a homogeneous material under either biaxial normal loading or combined normal and tangential
loading. The plots are analyzed depending on the type of stress state
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 11, pp. 30–39, November 2006. 相似文献
11.
The structural theory of microdamage of homogeneous and composite materials is generalized. The theory is based on the equations
and methods of the mechanics of microinhomogeneous bodies with stochastic structure. A single microdamage is modeled by a
quasispherical pore empty or filled with particles of a damaged material. The accumulation of microdamages under increasing
loading is modeled as increasing porosity. The damage within a single microvolume is governed by the Huber-Mises or Schleicher-Nadai
failure criterion. The ultimate strength is assumed to be a random function of coordinates with power-law or Weibull one-point
distribution. The stress-strain state and effective elastic properties of a composite with microdamaged components are determined
using the stochastic equations of elasticity. The equations of deformation and microdamage and the porosity balance equation
constitute a closed-form system of equations. The solution is found iteratively using conditional moments. The effect of temperature
on the coupled processes of deformation and microdamage is taken into account. Algorithms for plotting the dependences of
microdamage and macrostresses on macrostrains for composites of different structure are developed. The effect of temperature
and strength of damaged material on the stress-strain and microdamage curves is examined
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 6, pp. 3–42, June 2007. 相似文献
12.
I. A. Banshchikova A. F. Nikitenko 《Journal of Applied Mechanics and Technical Physics》2006,47(5):747-756
The Rabotnov kinetic creep theory was used to calculate the stress-strain state and damage accumulation in the material of
axisymmetrically loaded circular and ring plates at any time before the beginning of fracture. It is shown that the solution
of the problem can be reduced to solving the same problem under the assumption of steady-state creep of the material. The
unsteady creep problem is solved by multiplying the known solution of the steady-state creep problem by certain functions
of the coordinates and time, which are determined from a corresponding system of equations.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 5, pp. 157–168, September–October, 2006. 相似文献
13.
Yu. V. Egunov A. V. Kochetkov 《Journal of Applied Mechanics and Technical Physics》1999,40(1):183-189
The nonlinear dynamics of hydroelastically connected, plane curvilinear rods is studied. We take into account the reciprocal
effect of deformation and hydrodynamics processes, large displacements and strains of the rods, the preliminary static stress-strain
state, and the nonstationary fluid flow. A method is proposed for numerical solution of initial boundary-value problems. The
effects of the hydroelastic interaction are investigated. The effect of various factors on the dynamics of a damaged pipeline
is analyzed.
Institute of Mechanics, Nizhnii Novgorod State University, Nizhnii Novgorod 603600. Translated from Prikladnaya Mekhanika
i Tekhnicheskaya Fizika, Vol. 40, No. 1, pp. 212–219, January–February, 1999. 相似文献
14.
Conclusion We have surveyed the existing methods of determining the stress-strain state and fracture toughness of gas and oil lines.
The discussion illustrated the promise of methods of evaluating the stress-strain state that are based on allowance for the
strain-hardening of the material of the pipe or plastic indicators attached to its surface and deformed along with it. The
first method, being destructive, can be used to evaluate the effect of different shaping methods on the strength of the pipe
material, to analyze accidental pipeline fractures, and to generate a data bank on the stress-strain state of sections of
a pipeline that have lost their longitudinal stability and are scheduled for replacement. Information obtained from the first
method can also be used to establish correlations between the geometric parameters of such sections (deflection, curvature)
and their stress-strain state. This will make it possible, with the use of reliable statistical methods, to predict the stress
level on curved sections of pipelines without having to cut out samples for testing and analysis.
Translated from Prikladnaya Mekhanika, Vol. 33, No. 8, pp. 3–30, August, 1997. 相似文献
15.
V. D. Bondar’ 《Journal of Applied Mechanics and Technical Physics》1999,40(2):360-366
The relations of the nonlinear model of the theory of elasticity are considered. The Cauchy and the strain gradient tensors
are taken to be the characteristics of the stress-strain state of a body. Sufficient conditions under which the static equations
of elasticity are of elliptic type are established. These conditions are expressed in the form of constraints imposed on the
derivatives of the elastic potential with respect to the strain-measure characteristics. The cases of anisotropic and isotropic
bodies are treated, including the case where the Almansi tensor is taken to be the strain measure. The plane strain of a body
is investigated using actual-state variables.
Novosibirsk State University, Novosibirsk 630090. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40,
No. 2, pp. 196–203, March–April, 1999. 相似文献
16.
复杂应力状态下岩土材料非线性本构模型研究 总被引:1,自引:0,他引:1
基于统一强度理论,将洛德参数引入统一强度理论,推导出材料的统一强度参数,进而分析中间主应力以及主剪应力系数对材料统一强度参数的影响。在此基础上,对邓肯张双曲线模型进行改进,使得该模型能够反映复杂应力状态下的应力应变关系。采用粘土的平面应变试验进行验证,结果表明:在平面应变情况下,当b=0.4时,模型能够较好地反映粘土的应力应变关系,及其强度参数。分析了洛德参数以及中间主应力系数对模型的影响,进一步说明岩土材料存在主应力效应。该模型能够反映不同材料在复杂应力状态下的应力应变关系,有其更为广泛的适用性。 相似文献
17.
The edge effect in layered composite material is studied using the piecewise-homogeneous body model and the exact equations
of the theory of elasticity. It is assumed that continuously distributed normal forces act at the edges of the reinforcing
layers. A plain strain state is considered and the stresses are expressed in terms of the solutions of a system of dual singular
integral equations. The singularity of the stresses is determined by the solution procedure. The concentration of the reinforcing
layers is assumed low and the interaction between them is not taken into account. A numerical algorithm is developed and numerical
results on the stress distribution are presented
Published in Prikladnaya Mekhanika, Vol. 44, No. 4, pp. 134–144, April 2008. 相似文献
18.
The paper proposes a numerical technique for analysis of the elastoplastic stress-strain state of flexible layered shells
of revolution under axisymmetric loading. It is assumed that the shells are made of isotropic and transversely isotropic materials
with different moduli in tension and compression. The technique is based on a geometrically nonlinear theory of shells that
takes into account the squared angles of rotation and the Kirchhoff-Love hypotheses for a layer stack. The deformation of
isotropic materials is described using the theory of deformation along paths of small curvature. The deformation of transversely
isotropic materials is described using the theory of elasticity with different moduli in tension and compression. The problem
is solved by the method of successive approximations. A numerical example is given
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 11, pp. 31–42, November 2007. 相似文献
19.
This work deals with the mode III fracture problem of a cracked functionally graded piezoelectric surface layer bonded to
a cracked functionally graded piezoelectric substrate. The cracks are normal to the interface and the electro-elastic material
properties are assumed to be varied along the crack direction. Potential and flux types of boundary condition are assigned
on the edge of the surface layer. The problem under the assumptions of impermeable and permeable cracks can be formulated
to the standard singular integral equations, which are solved by using the Gauss–Chebyshev technique. The effects of the boundary
conditions, the material properties and crack interaction on the stress and electric displacement intensity factors are discussed. 相似文献
20.
The problem of the interaction of a crack and a dislocation in a medium with a nonlinear stress-strain law is considered for the case of a semi-infinite crack in a displacement loaded strip under longitudinal shear deformation. A power law stress-strain relation is considered and the dislocation is assumed positioned so that the net effect of its interaction with the crack is to produce a zero stress intensity factor when combined with the effect of the applied displacements. Thus the Atkinson-Kay superdislocation model of a relaxed crack tip is extended to the situation where the material satisfies a power-law stress-strain relationship. 相似文献