共查询到20条相似文献,搜索用时 31 毫秒
1.
B. D. Annin V. V. Alekhin S. N. Korobeinikov 《Journal of Applied Mechanics and Technical Physics》2000,41(5):937-944
The equations of quasistatic deformation of elastoplastic bodies are considered in a geometrical linear formulation. After
discretization of the equations with respect to spatial variables by the finite-element method, the problem of determining
equilibrium onfigurations reduces to integration of a system of nonlinear ordinary differential equations. In the ultimate
state of a body of an ideal elastoplastic material, the matrix of the system degenerates and the problem becomes singular.
A regularization algorithm for determining solutions of the problems for the ultimate states of bodies is proposed. Numerical
solutions of test problems of determining the ultimate loads and equilibrium configurations for ideal elastoplastic bodies
confirm the reliability of the regularization algorithm proposed.
Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 5, pp. 196–204, September–October, 2000. 相似文献
2.
S. V. Khabirov 《Journal of Applied Mechanics and Technical Physics》2009,50(2):207-212
This paper deals with one insufficiently studied submodel of invariant solutions of rank 1 of the equations of gas dynamics.
It is shown that, in cylindrical coordinates, the submodel without swirling reduces to a system of two ordinary differential
equations. For the equation of state with additional invariance, a self-similar system is obtained. A pattern of phase trajectories
is constructed, and particle motion is studied using asymptotic methods. The obtained solutions describe unsteady flows over
axisymmetric bodies with possible strong discontinuities.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 2, pp. 46–52, March–April, 2009. 相似文献
3.
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
4.
Maria J. Martín-Alfonso Francisco Martínez-Boza Pedro Partal Crispulo Gallegos 《Rheologica Acta》2006,45(4):357-365
Transportation and consumption of petroleum products around the world have created a potential risk for oil spills in the environment. Knowledge of high-pressure rheological behaviour of heavy crude oil fractions, which are usually transported in oil tankers, is very important to design deep recovering operations of the oil remaining in the tanks after an accident. The effect of pressure on the viscosity of these materials is not well understood, this is mainly due to experimental constraints involving high-pressure rheology measurements at low shear rates. Consequently, the overall objective of this work is to model the temperature–pressure–viscosity dependence of a selected heavy fuel oil in a wide range of pressure and temperature. With this aim, viscous flow tests at different temperatures and differential pressures and modulated differential scanning calorimetry tests were carried out on the heavy fuel oil selected. A temperature–pressure–viscosity model (FMT model) fits fairly well the experimental results obtained in the whole differential pressure range studied. However, viscosity values at temperatures lower than 10°C cannot be predicted due to microstructural changes associated with the solidification process of the heaviest components of the fuel oil tested.Paper presented at the European Rheology Conference (AERC) held in Grenoble, France, April 21–23, 2005. 相似文献
5.
The rheological equations of state of the dispersed medium are obtained for one-dimensional flows of monodisperse systems
in which the acceleration of the external body force field and the average interphase slip velocity are collinear, on the
basis of an analysis of the pseudoturbulence properties.
Ekaterinburg. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.2, pp. 53–65, March–April,
1994. 相似文献
6.
We introduce the notion of invariant surfaces for inhomogeneous stochastic differential equations with jumps. The results
obtained enable one to determine invariant surfaces for stochastic differential equations of the type indicated.
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Translated from Neliniini Kolyvannya, Vol. 8, No. 2, pp. 234–240, April–June, 2005. 相似文献
7.
N. I. Ostrosablin 《Journal of Applied Mechanics and Technical Physics》2006,47(4):564-572
This paper deals with the general formulas of affine transformations that preserve invariance of the static equations of the
linear theory of elasticity in the case of arbitrary anisotropic materials. The invariance of the equations with respect to
affine transformations allows one to model a given anisotropic material by another material. All anisotropic materials are
divided into classes of mutually congruent materials. The congruency conditions are obtained for orthotropic and isotropic
materials and for orthotropic and transversely isotropic materials.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 4, pp. 124–134, July–August, 2006. 相似文献
8.
A nonlinear mathematical model of a system of n rigid bodies undergoing translational vibrations under inertial loading is
constructed. The system includes ball supports as a seismic-isolation mechanism and electromagnetic dampers controlled via
an inertial feedback channel. A system of differential dynamic equations in normal form describing accelerative damping is
derived. The frequencies of small undamped vibrations are calculated. A method for analyzing the dynamic coefficients of rigid
bodies subject to accelerative damping is developed. The double phase–frequency resonance of a two-mass system is studied 相似文献
9.
Z. Opluštil 《Nonlinear Oscillations》2008,11(3):384-406
New efficient sufficient conditions are obtained for the solvability and the unique solvability of a nonlocal boundary-value
problem for nonlinear functional differential equations.
Published in Neliniini Kolyvannya, Vol. 11, No. 3, pp. 365–387, July–September, 2008. 相似文献
10.
A. V. Fedorov V. M. Fomin T. A. Khmel' 《Journal of Applied Mechanics and Technical Physics》2005,46(6):835-841
A physicomathematical model is developed, which describes gas flows inside rapidly rotating bodies made of cellular-porous
materials. Asymptotic and numerical solutions are obtained for some problems of forced centrifugal convection inside cylindrical
cellular-porous bodies. The effect of the governing parameters (drag coefficient and dimensionless length of the cylinder)
on characteristics and types of flows is considered.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 6, pp. 78–85, November–December, 2005. 相似文献
11.
A. N. Guz 《International Applied Mechanics》2005,41(8):944-955
The ultrasonic nondestructive method for determining stresses in near-surface layers of solid bodies is based on the laws
governing the propagation of elastic surface waves in bodies with initial (residual) stresses. These laws are established
within the framework of the linearized three-dimensional theory of waves in bodies with initial (residual) stresses. The dispersion
equations in associated problems are solved by computational methods. The nondestructive method and measuring instruments
and devices are described. Some examples of nondestructive determination of welding-induced residual stresses and operating
stresses in near-surface layers of materials are presented
Presented at the International Conference on Computational and Experimental Engineering and Sciences (ICCES'04) (Madeira,
Portugal, July 26–29, 2004) and published in the journal Computer Modeling in Engineering and Sciences (CMES).
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Published in Prikladnaya Mekhanika, Vol. 41, No. 8, pp. 130–144, August 2005. 相似文献
12.
N. K. Prykarpats’ka 《Nonlinear Oscillations》2005,8(4):526-540
The generalized method of characteristics is developed within the framework of the geometric Monge picture. Hopf-Lax-type
extremality solutions are obtained for a broad class of Cauchy problems for nonlinear partial differential equations of the
first and higher orders. A special Hamilton-Jacobi-type case is analyzed separately. An exact extremality Hopf-Lax-type solution
of the Cauchy problem for the nonlinear Burgers equation is obtained, and its linearization to the Hopf-Cole expression and
to the corresponding Airy-type linear partial differential equation is found and discussed.
Published in Neliniini Kolyvannya, Vol. 8, No. 4, pp. 529–543, October–December, 2005. 相似文献
13.
Yu. A. Chirkunov 《Journal of Applied Mechanics and Technical Physics》2009,50(2):213-219
An algorithm is proposed which allows all conservation laws for a system of differential equations to be to obtained from
its one zero-order conservation law for which the general rank of the Jacobi matrix is equal to the number of independent
variables of the system. The efficiency of the algorithm is shown by examples of the equations of gas dynamics, for which
new conservation laws are derived. For the equations considered, additional symmetry properties related to these conservation
laws are established.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 2, pp. 53–60, March–April, 2009. 相似文献
14.
The stress distribution in an infinite matrix containing a row of antiphase periodically curved fibers is studied using the
piecewise-homogeneous body model and the exact three-dimensional equations of elasticity theory for anisotropic bodies. It
is assumed that the midlines of the fibers are located in the same plane and the materials of the fibers are the same. Numerical
results are presented for the case where the materials of the fibers and matrix are isotropic and homogeneous
Published in Prikladnaya Mekhanika, Vol. 42, No. 4, pp. 136–144, April 2006. 相似文献
15.
N. A. Abrosimov V. G. Bazhenov N. A. Kulikova 《Journal of Applied Mechanics and Technical Physics》2006,47(3):412-418
A method is proposed for determining the stiffness and rheological characteristics of composite materials, which is based
on minimizing the disagreement between experimental data and results of numerical simulations of deformation of hemispherical
shells under explosive loading. The damping characteristics of randomly reinforced polymer materials are analyzed with the
use of this method.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 3, pp. 126–133, May–June, 2006. 相似文献
16.
The dynamic rheological properties of segmented polyurethane based on polycaprolactone diol (PU-PCL diol) and poly (ɛ-caprolactone) (PCL) blends were experimentally examined and theoretically analyzed using Palierne model. PU–PCL
diol was melt blended with PCL in three different ratios of 20, 30, and 40%. Initial modeling attempts failed to fit the experimental
data of these blends, as the model overpredicted their rheological data. This failure is believed to be due to partial dissolution
of PCL in PU. According to our obtained results from differential scanning calorimetry and dynamic thermal mechanical analysis,
pure PU–PCL diol is diluted by its homopolymer. By calculating the complex modulus of this diluted matrix using a simple mixing rule and its
incorporation into the model, good fitting of the Palierne equation to the experimental data was obtained. 相似文献
17.
D. L. Blackmore N. K. Prykarpats’ka V. H. Samoilenko E. Wachnicki M. Pytel-Kudela 《Nonlinear Oscillations》2007,10(1):22-31
We develop the Cartan-Monge geometric approach to the characteristic method for nonlinear partial differential equations of
the first and higher orders. The Hamiltonian structure of characteristic vector fields related with nonlinear partial differential
equations of the first order is analyzed, and tensor fields of special structure are constructed for defining characteristic
vector fields naturally related with nonlinear partial differential equations of higher orders.
Published in Neliniini Kolyvannya, Vol. 10, No. 1, pp. 26–36, January–March, 2007. 相似文献
18.
The paper deals with the existence of positive (nonnegative) solutions of linear homogeneous impulsive differential equations.
The main result is also applied to the investigation of a similar problem for higher-order linear homogeneous impulsive differential
equations. All results are formulated in terms of coefficients of the equations.
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Published in Neliniini Kolyvannya, Vol. 8, No. 3, pp. 291–297, July–September, 2005. 相似文献
19.
A closed system of differential equations describing a foam as a viscoelastic compressible continuum is obtained on the basis
of the general theory of the mechanics of deformable continua [3–5].
Moscow. Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 91–95, September–October, 1988. 相似文献
20.
Yu. A. Chirkunov 《Journal of Applied Mechanics and Technical Physics》2009,50(3):413-418
A sufficient condition for the absence of tangent transformations admitted by second-order quasi-linear differential equations
and a sufficient condition for linear autonomy of operators of the Lie group of transformations admitted by second-order weakly
nonlinear differential equations are found. A theorem on the structure of the first-order conservation laws for second-order
weakly nonlinear differential equations is proved. A classification of second-order linear differential equations with two
independent variables in terms of first-order conservation laws is proposed.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 3, pp. 64–70, May–June, 2009. 相似文献