共查询到20条相似文献,搜索用时 562 毫秒
1.
V. L. Shkuratnik Yu. L. Filimonov S. V. Kuchurin 《Journal of Applied Mechanics and Technical Physics》2006,47(2):236-240
This paper gives results from experimental studies of the acoustic emission and strain memory effects in anthracite samples
under cyclic loading. Trends and regularities were found in the formation and manifestation of the acoustic emission memory
effect of coal in nonmonotonic uniaxial tests.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 2, pp. 103–109, March–April, 2006. 相似文献
2.
Analytic and numerical analyses are carried out to ascertain whether the theories of thin and medium-thickness shells can
be used to calculate the thermoelastic state of shells of revolution. It is shown that the theory of thin shells should be
used in the case of thermal loading and the theory of medium-thickness shells in the case of mechanical loading
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 5, pp. 58–67, May 2008. 相似文献
3.
The vibration and vibrational heating of a rectangular prism with copper and polyethylene layers is studied by solving numerically
a coupled problem of thermoelasticity. The cases of kinematic and mechanical harmonic shear loads on a section of the prism
surface are examined. Local heating regions are revealed. They are due to the stress fields in the neighborhood of the points
at which the type of boundary conditions changes. The temperature–time curves have preresonance, resonant, and postresonance
sections. The heating process reaches a steady thermal state under kinematic loading and may become avalanche-like (which
is typical of thermal instability) under mechanical loading
Translated from Prikladnaya Mekhanika, Vol. 45, No. 2, pp. 70–78, February 2009. 相似文献
4.
V. M. Tikhomirov 《Journal of Applied Mechanics and Technical Physics》2008,49(5):864-871
Crack propagation under alternating loading is investigated. Relations between the growth rate of a fatigue defect and loading
parameters and the expression for the stress intensity factor are derived for compression of a cracked solid taking into account
the possible contact of the crack faces. A model for the deformation of a small region near the crack tip is proposed which
allows one to formulate the conditions of residual opening of a growing fatigue crack. The experimental data obtained in tests
of steel samples are compared with the results of calculation using the developed procedure.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 5, pp. 190–198, September–October, 2008. 相似文献
5.
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
6.
R. A. Abirov 《Journal of Applied Mechanics and Technical Physics》2009,50(1):107-111
A model of plasticity for a transversely isotropic material with allowance for complex loading is developed, based on results
of experiments with homogeneous cylindrical specimens of isotropic materials. An empirical model of plasticity for isotropic
metals is constructed with allowance for vector properties of the material. The model is extended to a particular case of
anisotropy.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 1, pp. 128–133, January–February, 2009. 相似文献
7.
The paper proposes an analytic procedure based on the method of characteristics to study the nonstationary thickness vibration
of a piezoelectric layer polarized across the thickness and subjected to dynamic mechanical loading. The problem is solved
for a suddenly applied harmonic mechanical load. The dynamic electroelastic state of the layer is analyzed
Translated from Prikladnaya Mekhanika, Vol. 45, No. 1, pp. 82–89, January 2009. 相似文献
8.
V. S. Kirilyuk 《International Applied Mechanics》2008,44(10):1106-1118
The static equilibrium of a transversely isotropic magnetoelectroelastic body with a plane crack of arbitrary shape in the
isotropy plane under antisymmetric mechanical loading is studied. The relationships between the stress intensity factors (SIFs)
for an infinite magnetoelectroelastic body and the SIFs for a purely elastic body with the same crack and under the same antisymmetric
loading are established. This enables the SIFs for a magnetoelectroelastic body to be found directly from the analogous problem
of elasticity. As an example of using this result, the SIFs for penny-shaped, elliptic, and parabolic cracks in a magnetoelectroelastic
body under antisymmetric mechanical loading are found
Translated from Prikladnaya Mekhanika, Vol. 44, No. 10, pp. 37–51, October 2008. 相似文献
9.
N. V. Chertova Yu. V. Grinyaev 《Journal of Applied Mechanics and Technical Physics》2006,47(3):401-405
A relation governing the plastic-strain evolution under applied stresses is obtained within the field theory of defects to
analyze the specific features of deformation under sign-varying cyclic loading. The effect of the applied stress amplitude,
loading frequency, and cycle skewness on the deformation process under uniaxial loading conditions is studied. Specific features
of the plastic-strain evolution in a stable deformation process are considered, and the time to failure of the system in an
unstable process is determined.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 3, pp. 112–118, May–June, 2006. 相似文献
10.
The method of characteristics is used to obtain an analytical solution describing the thickness vibrations of a piezoelectric
layer polarized across the thickness and subjected to a nonstationary electric potential. The features of how the vibrations
are excited and propagate under electric loading are studied. The dynamic electromechanical state of the layer is analyzed.
The electric and mechanical characteristics as functions of time are plotted
Translated from Prikladnaya Mekhanika, Vol. 44, No. 10, pp. 23–27, October 2008. 相似文献
11.
12.
A. V. Zheldubovskii A. D. Pogrebnyak V. V. Kasperskaya 《International Applied Mechanics》2008,44(3):313-319
The paper studies the fatigue resistance of metallic samples subjected to high-cycle loading and microhardness measurement.
The fatigue damage of materials during loading is identified as decrease in the thickness of the barrier surface layer, which
prevents fatigue failure. It is shown that the thickness of this layer is independent of the plastic characteristics of the
material and the level of stress. A method to evaluate accumulated fatigue damage is developed. Kinetic curves of damage accumulation
are analyzed. Methods to predict fatigue characteristics are proposed
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 3, pp. 86–95, March 2008. 相似文献
13.
V. M. Greshnov 《Journal of Applied Mechanics and Technical Physics》2008,49(6):1021-1029
Scalar and tensor models of plastic flow of metals extending plasticity theory are considered over a wide range of temperatures
and strain rates. Equations are derived using the physico-phenomenological approach based on modern concepts and methods of
the physics and mechanics of plastic deformation. For hardening and viscoplastic solids, a new mathematical formulation of
the boundary-value plasticity problem taking into account loading history is obtained. Results of testing of the model are
given. A numerical finite-element algorithm for the solution of applied problems is described.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 6, pp. 159–169, November–December, 2008. 相似文献
14.
N. P. Plakhtienko 《International Applied Mechanics》2009,45(7):786-796
A design model for a chain system of N elastically linked rigid bodies with a spheroidal gravity-friction damper is proposed. The Lagrange–Painlevé equations of
the first kind are used to construct nonlinear dynamical models of a mechanical system undergoing translational vibrations
about the equilibrium position. The conditions under which the system moves in one plane are established. The double nonstationary
phase–frequency resonance of a system with N = 2 is analyze. After the numerical integration of the systems of differential equations, the phase–frequency surfaces are
plotted and examined for several combinations of system parameters under two-frequency loading 相似文献
15.
This article presents the implementation of the constitutive model of Wheeler (Geotechnique 53(1):41–54, 2003) for coupling
of hydraulic hysteresis and mechanical behavior of unsaturated soils in a fully coupled transient hydro-mechanical finite
element (FE) model (computer code UNSATEX) developed by the authors. The constitutive model considers the effects of irreversible
changes of degree of saturation on stress–strain behavior and the influence of plastic volumetric strains on the water retention
behavior. The mathematical framework and the numerical implementation of the constitutive model are presented and discussed.
The FE model is verified and validated against analytical predictions [obtained using the model of Wheeler (Geotechnique 53(1):41–54,
2003] as well as experimental results from the literature involving unsaturated soils undergoing various combinations of drying,
wetting, loading, unloading, and reloading paths. Comparison of the results shows that the developed FE model can be used
to predict various aspects of the behavior of unsaturated soils under drying and wetting as well as loading and unloading
paths. The merits and limitations of the FE model are highlighted. 相似文献
16.
O. S. Bogdanova 《International Applied Mechanics》2008,44(8):938-945
A modified δc-model is used to study the limiting state of an orthotropic plate weakened by a periodic row of collinear cracks and satisfying
a general failure criterion. The failure mechanism of the plate is analyzed.Astudy is made of the effects of the degree of
orthotropy, the biaxiality of external loading, and the geometrical parameters on the fracture process zones at the crack
tips and the limiting state of the plate. The safe loading of an orthotropic viscoelastic plate with a periodic row of collinear
cracks is examined. The effect of the rheological parameters on the safe-load region is studied
Translated from Prikladnaya Mekhanika, Vol. 44, No. 8, pp. 126–135, August 2008. 相似文献
17.
A series of triaxial compression experiments were preformed for the coarse marble samples under different loading paths by
the rock mechanics servo-controlled testing system. Based on the experimental results of complete stress-strain curves, the
influence of loading path on the strength and deformation failure behavior of coarse marble is made a detailed analysis. Three
loading paths (Paths I–III) are put forward to confirm the strength parameters (cohesion and internal friction angle) of coarse
marble in accordance with linear Mohr-Coulomb criterion. Compared among the strength parameters, two loading paths (i.e. Path
II by stepping up the confining pressure and Path III by reducing the confining pressure after peak strength) are suggested
to confirm the triaxial strengths of rock under different confining pressures by only one sample, which is very applicable
for a kind of rock that has obvious plastic and ductile deformation behavior (e.g. marble, chalk, mudstone, etc.). In order
to investigate re-fracture mechanical behavior of rock material, three loading paths (Paths IV–VI) are also put forward for
flawed coarse marble. The peak strength and deformation failure mode of flawed coarse marble are found depending on the loading
paths (Paths IV–VI). Under lower confining pressures, the peak strength and Young’s modulus of damage sample (compressed until
post-peak stress under higher confining pressure) are all lower compared with that of flawed sample; moreover mechanical parameter
of damage sample is lower for the larger compressed post-peak plastic deformation of coarse marble. However under higher confining
pressures (e.g. σ
3 = 30 MPa), the axial supporting capacity and elastic modulus of damage coarse marble (compressed until post-peak stress under
lower confining pressure) is not related to the loading path, while the deformation modulus and peak strain of damage sample
depend on the difference of initial confining pressure and post-peak plastic deformation. The friction among crystal grains
determines the strength behavior of flawed coarse marble under various loading paths. In the end, the effect of loading path
on failure mode of intact and flawed coarse marble is also investigated. The present research provides increased understanding
of the fundamental nature of rock failure under different loading paths. 相似文献
18.
V. N. Chekhov 《International Applied Mechanics》2005,41(12):1350-1356
The piecewise-homogeneous model and the three-dimensional theory of stability for small and finite subcritical strains are
used to study the formation of folds in layered rock masses of the Earth’s crust under biaxial loading. The general statement
of the problem is given, and the governing characteristic equations are derived. Numerical results are presented for a layered
rock mass composed of two alternating layers
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Translated from Prikladnaya Mekhanika, Vol. 41, No. 12, pp. 26–34, December 2005. 相似文献
19.
P. Z. Lugovoi V. F. Meish B. P. Rybakin G. V. Secrieru 《International Applied Mechanics》2008,44(7):788-793
A numerical algorithm to determine the stress-strain state of a reinforced cylindrical shell subject to impulsive loading
is elaborated. Results from a numerical analysis of the dynamic behavior of a reinforced elastoplastic shell under explosive
loading are presented
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 7, pp. 83–90, July 2008. 相似文献
20.
A coupled dynamic problem of thermomechanics is formulated based on a thermodynamically consistent modification of the Bodner-Partom
model. This formulation is used to analyze the thermomechanical state of an aluminum cylinder under axial impulsive loading.
The problem is solved by the finite-element method. Time integration is performed by the Crank-Nicholson scheme. Reversible
and irreversible thermal changes are studied
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Translated from Prikladnaya Mekhanika, Vol. 41, No. 8, pp. 66–71, August 2005. 相似文献