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1.
The thermal instability of a rectangular prism under vibrational heating is studied solving a coupled problem of thermoviscoelasticity
and using finite-element modeling. The prism has copper and polyethylene or polymethylmethacrylate layers and undergoes high-frequency
mechanical or kinematic compression. It is established that in the case of polyethylene, thermal instability occurs under
mechanical loading and does not occur under kinematic loading. In the case of polymethylmethacrylate, thermal instability
occurs under both kinds of loading. This is because of the increase in the shear and bulk loss compliances with temperature
for each of the polymers. At the transformation temperature, shear dissipation goes over into bulk dissipation, which is predominant
in rather thin polymeric layers. Dynamicity influences the critical loads both qualitatively and quantitatively 相似文献
2.
O. P. Chervinko I. K. Senchenkov N. N. Yakimenko 《International Applied Mechanics》2007,43(6):647-653
The vibrations and self-heating of a viscoelastic prism with a cylindrical inclusion under harmonic loading are studied through
numerical simulation. The effects of the stiffness of the inclusion and the mechanical and kinematic types of loading on kinetics,
spatial temperature distribution, and thermal instability parameters are examined
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 6, pp. 73–81, June 2007. 相似文献
3.
V. S. Kirilyuk 《International Applied Mechanics》1999,35(9):889-896
The feasibility of controlling the stress intensity factors for plane cracks of arbitrary form (distributed in a plane perpendicular
to isotropy axis in a transversely isotropic material) which are subjected to symmetric mechanical loading by heating the
material is demonstrated by using the congruence theorem and making an analogy between isotropic and transversely isotropic
materials based on the theory of thermoelasticity. It is shown that a thermal load which fully compensates for the mechanical
load can be created within the range in which the material behaves linearly. If it turns out to be technically impossible
to create the necessary thermal load, a simpler temperature regime can be chosen that will “cancel” the mechanical force field
with a certain factor of safety.
S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev. Translated from Prikladnaya Mekhanika,
Vol. 35, No. 9, pp. 29–37, September, 1999. 相似文献
4.
S. V. Stankevich G. A. Shvetsov 《Journal of Applied Mechanics and Technical Physics》1999,40(2):325-330
A comparative analysis of the dependences of the ultimate (under heating conditions) velocity on the dimensions and thermal
properties of the projectile and on the length of the railgun is performed on the basis of a numerical solution of two-dimensional
unsteady equations of magnetic-field diffusion and heat transfer. Homogeneous and multilayer projectiles and homogeneous rails
and rails with a resistive coating are considered. It is shown that the ultimate kinematic characteristics of railgun accelerators
of solids can be considerably increased by changing the structure and thermal properties of the materials of the projectile
and the electrodes.
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. 156–162, March–April, 1999. 相似文献
5.
The vibrations and dissipative heating of a hinged shallow shell made of viscoelastic piezoelectric material and subject to
harmonic electric loading are considered. The basic relations are obtained by using the Kirchhoff-Love mechanical hypotheses
supplemented with the respective hypotheses for electric quantities. Analytical solutions of both electromechanical and thermal
problems are derived for the case where the temperature is constant along the shell thickness.
Translated from Prikladnaya Mekhanika, Vol. 36, No. 6, pp. 78–87, June, 2000. 相似文献
6.
X. F. Ding T. Furukawa H. Nakanishi 《Archive of Applied Mechanics (Ingenieur Archiv)》2002,72(2-3):107-118
Summary This paper investigates the stress-focusing effect in an infinitely long cylinder under rotationally asymmetrical instantaneous
thermal loading on the basis of the generalized thermoelastic Lord–Shulman (L-S) and Green–Lindsay (G-L) theories. Combined
forms of the governing equations of both theories are given in a cylindrical coordinate system. The two-dimensional generalized
thermoelastic problems are solved by numerical inversion of Laplace transform. Calculations have been performed to find distributions
of thermal stresses on the basis of the L-S theory. Stress-focusing phenomena under different heating conditions are presented.
The effects of thermomechanical coupling and relaxation time on the stress-focusing phenomena as well as the singularity of
stresses are discussed.
Received 15 November 2000; accepted for publication 15 November 2001 相似文献
7.
The basic equations of the theory of thermoviscoelastic thin-walled plates with piezoelectric sensors and actuators under
monoharmonic mechanical and electric loading are derived using the Kirchhoff–Love hypotheses. The thermomechanical behavior
of passive and piezoactive materials is described using the concept of complex characteristics. Methods of solving nonlinear
problems of active damping of thermomechanical vibrations of plates with sensors and actuators are considered. The effect
of dissipative heating on the damping of axisymmetric vibrations of a thermoviscoelastic solid circular plate is analyzed
as an example 相似文献
8.
The forced monoharmonic bending vibrations and dissipative heating of a piezoelectric circular sandwich plate under monoharmonic
mechanical and electrical loading are studied. The core layer is passive and viscoelastic. The face layers (actuators) are
piezoelectric and oppositely polarized over the thickness. The plate is subjected to harmonic pressure and electrical potential.
The viscoelastic behavior of the materials is described by complex moduli dependent on the temperature of heating. The coupled
nonlinear problem is solved numerically. A numerical analysis demonstrates that the natural frequency, amplitude of vibrations,
mechanical stresses, and temperature of dissipative heating can be controlled by changing the area and thickness of the actuator.
It is shown that the temperature dependence of the complex moduli do not affect the electric potential applied to the actuator
to compensate for the mechanical stress
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 1, pp. 79–89, January 2008. 相似文献
9.
V. P. Shevchenko 《International Applied Mechanics》2007,43(7):707-725
This paper deals with fundamental-solution methods applied to stress-concentration problems for thin elastic shells. Publications
concerned with the relevant division of the theory of plates and shells are reviewed. The theories behind the methods are
described, and specific results for static and dynamic concentrated loads are presented. The capabilities of the methods are
illustrated by fracture problems for orthotropic shells with notches and holes under mechanical loading and for isotropic
shells with notches under thermal loading
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 7, pp. 3–25, July 2007. 相似文献
10.
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
11.
A. S. Voznesenskii K. B. Ustinov V. L. Shkuratnik 《Journal of Applied Mechanics and Technical Physics》2006,47(4):582-587
A theoretical model of changes in acoustic emission activity in a geomaterial under continuous or stepwise mechanical loading
is justified. Based on this model, the experimentally found laws of emission in the region of the maximum compaction of rock
samples with different rates of mechanical loading of these samples are analyzed.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 4, pp. 145–152, July–August, 2006. 相似文献
12.
The method of successive approximations is used to determine the thermoelastoplastic stress-strain state of isotropic and
transversally isotropic laminated shells of revolution under axisymmetric loading. Hill’s theory of plasticity with isotropic
hardening is used to describe the deformation of transversely isotropic materials, while the theory of deformation along paths
of small curvature is used to describe the deformation of isotropic materials. The elastoplastic stress-strain state of a
two-layer cylindrical shell under mechanical and thermal loads is analyzed
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 6, pp. 71–80, June 2006. 相似文献
13.
Hamdy M. Youssef Amnah H. Al-Harby 《Archive of Applied Mechanics (Ingenieur Archiv)》2007,77(9):675-687
In this work, we will consider an infinite elastic body with a spherical cavity and constant elastic parameters. The governing
equations are taken in the context of the two-temperature generalized thermoelasticity theory (Youssef in J Appl Math Mech
26(4):470–475 2005a, IMA J Appl Math, pp 1–8, 2005). The medium is assumed initially quiescent. Laplace transform and state
space techniques are used to obtain the general solution for any set of boundary conditions. The general solution obtained
is applied to a specific problem when the bounding plane of the cavity is subjected to thermal loading (thermal shock and
ramp-type heating). The inverse Laplace transforms are computed numerically using a method based on Fourier expansion techniques.
Some comparisons have been shown in figures to estimate the effect of the two-temperature and the ramping parameters. 相似文献
14.
A. A. Rogovoi 《Journal of Applied Mechanics and Technical Physics》2008,49(1):136-141
Polar decomposition tensors are constructed for slightly disturbed kinematic elastic, inelastic, and thermal strain tensors.
Provided that the inelastic and thermal site gradients are pure deformations without rotations, relations are obtained between
inelastic small strains and small rotations and between thermal small strains and small rotations which transform an intermediate
configuration to a close current configuration.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 1, pp. 165–172, January–February, 2008. 相似文献
15.
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
16.
C. M. Sands H. W. Chandler I. A. Guz Y. A. Zhuk 《Archive of Applied Mechanics (Ingenieur Archiv)》2010,80(2):161-173
This paper demonstrates that, at extreme levels of kinematic hardening, the traditional formulation of the Bodner–Partom model
can produce anomalous results. The reasons for this anomalous behaviour are explained, and a reformulated version of the model
is presented. This reformulation extends the range of the model to include levels of kinematic hardening that may be problematic
in the traditional formulation. The formulation of the model is adjusted so as to retain the rate dependency of the original
Bodner–Partom model; and to permit the values of the material parameters used with the traditional formulation to be re-used
with the extended model—with the exception only of the hardening coefficients which become dimensionless constants holding
different numerical values. This revised formulation also imposes associated flow, thereby ensuring phase consistency between
stress and plastic strain during non-proportional loading. In this way, the anomalies are removed, the range and stability
of the model is increased, and all the advantages and important features of the Bodner–Partom model are retained. 相似文献
17.
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
18.
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
19.
D. C. Pham 《Archive of Applied Mechanics (Ingenieur Archiv)》1998,68(10):711-718
Summary The kinematic shakedown method is used to evaluate the dynamic cyclic collapse loads for a clamped reinforced concrete plate.
The method, based on reduced kinematic formulae recently derived by the author, requires determination of the fictitious elastic
fields within the plates, in particular – their envelope corresponding to the external loads, and construction of potential
incremental collapse mechanisms. The load amplitude-frequency diagrams constructed should help to choose the necessary reinforcements
for the plate under given loading conditions.
Received 14 January 1998; accepted for publication 25 June 1998 相似文献
20.
The results of calculating a supersonic turbulent boundary layer on a flat plate in the presence of thermal energy supply
to the boundary layer are presented. Two methods of energy supply are considered: heating a local interval of the surface,
which is otherwise thermally insulated and using a local volume heat source. It is shown that for the same amount of heat
supplied to the gas volume heating leads, under certain conditions, to greater friction reduction than the surface heating.
Localization of the energy supply zone leads to the intensification of the viscous drag reduction effect and to a greater
decrease in the local friction coefficient, which extends a considerable distance downstream.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 48–56, January–February,
1997.
The work was carried out with financial support from the Russian Foundation for Fundamental Research (project No. 93-013-17600). 相似文献