共查询到20条相似文献,搜索用时 203 毫秒
1.
A. D. Zaikin 《Journal of Applied Mechanics and Technical Physics》2006,47(6):886-891
The behavior of a crack under uniaxial tension in the presence of reinforcement is studied. The reinforcing members (riveted
stiffeners) are modeled by point loads. Only four members nearest to the crack are taken into account. It is shown that stiffeners
allow one to arrest a crack and prevent its catastrophic growth. Relations between the geometrical and force characteristics
for which the crack is stabilized are obtained. The stabilization mechanism is discussed.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 6, pp. 137–143, November–December, 2006. 相似文献
2.
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
3.
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
4.
V. S. Kirilyuk 《International Applied Mechanics》2008,44(2):150-157
The elastic stress state in a piezoelectric body with an arbitrarily oriented elliptic crack under mechanical and electric
loads is analyzed. The solution is obtained using triple Fourier transform and the Fourier-transformed Green’s function for
an unbounded piezoelastic body. Solving the problem for the case of a crack lying in the isotropy plane, for which there is
an exact solution, demonstrates that the approach is highly efficient. The distribution of the stress intensity factors along
the front of a crack in a piezoelectric body under uniform mechanical loading is analyzed numerically for different orientations
of the crack
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 2, pp. 39–48, February 2008. 相似文献
5.
V. S. Kirilyuk 《International Applied Mechanics》2006,42(2):152-161
The static equilibrium of an electroelastic transversely isotropic space with a plane crack under antisymmetric mechanical
loads is studied. The crack is located in the plane of isotropy. Relationships are established between the stress intensity
factors (SIFs) for an infinite piezoceramic body and the SIFs for a purely elastic body with a crack of the same form under
the same loads. This makes it possible to find the SIFs for an electroelastic body without the need to solve specific electroelasitc
problems. As an example, the SIFs are determined for a piezoelastic body with penny-shaped and elliptic cracks under shear
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 2, pp. 32–42, February 2006. 相似文献
6.
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
7.
A. P. Shabanov 《Journal of Applied Mechanics and Technical Physics》2005,46(6):861-866
A specimen with a crack shaped like a thin long defect with parallel edges and a rounded tip of finite radius is considered.
When the specimen is subjected to compressive cyclic loads, the stresses in zones adjacent to the crack tip vary according
to a sign-variable cycle because of plastic strains occurring at the crack tip. This can cause fatigue-crack growth. Results
of numerical simulations and experimental data support the possibility of fatigue-crack growth in the field of compressive
external stresses.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 6, pp. 108–115, November–December, 2005. 相似文献
8.
E. V. Vtorushin 《Journal of Applied Mechanics and Technical Physics》2007,48(5):737-742
A homogeneous two-dimensional body with a crack of variable length is considered. At the crack edges, conditions are formulated
in the form of inequalities that describe mutual nonpenetration of the edges. The derivative of the elastic-energy functional
with respect to the length of the curvilinear crack is analyzed. It is shown that the derivative is independent of the crack
path, provided that the curve along which the crack propagates is reasonably smooth.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 5, pp. 138–145, September–October, 2007. 相似文献
9.
V. S. Kirilyuk 《International Applied Mechanics》2005,41(11):1263-1271
A static-equilibrium problem is solved for an electroelastic transversely isotropic medium with a flat crack of arbitrary
shape located in the plane of isotropy. The medium is subjected to symmetric mechanical and electric loads. A relationship
is established between the stress intensity factor (SIF) and electric-displacement intensity factor (EDIF) for an infinite
piezoceramic body and the SIF for a purely elastic material with a crack of the same shape. This allows us to find the SIF
and EDIF for an electroelastic material directly from the corresponding elastic problem, not solving electroelastic problems.
As an example, the SIF and EDIF are determined for an elliptical crack in a piezoceramic body assuming linear behavior of
the stresses and the normal electric displacement on the crack surface
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Translated from Prikladnaya Mekhanika, Vol. 41, No. 11, pp. 67–77, November 2005. 相似文献
10.
The mechanical model was established for the anti-plane fracture problem of a functionally graded coating–substrate system
with a coating crack inclined to the weak/micro-discontinuous interface. The Cauchy singular integral equation for the crack
was derived using Fourier integral transform, and the Lobatto–Chebyshev collocation method put up by Erdogan and Gupta was
used to get its numerical solution. Finally, the effects of the weak/micro-discontinuity of the interface on SIFs were analyzed,
the “affected regions” corresponding to the two crack tips have been obtained and their engineering significance was discussed.
It was indicated that, for the crack tip in the corresponding “affected region”, to reduce the weak-discontinuity of the interface
and to make the interface micro-discontinuous are the two effective ways to reduce the SIF, and the latter way always has
more remarkable SIF-reduction effect. For the crack tip outside the “affected region”, its SIF is mainly influenced by material
stiffness, and to prevent such a tip from growing toward the interface “softer coating and stiffer substrate” is a more advantageous
combination than “stiffer coating and softer substrate”. 相似文献
11.
A crack is represented as a continuous set of linear dislocations. Simple analytical expressions are obtained for the potential
and kinetic energies of the environment of moving cracks and the attached mass of cracks for an arbitrary form of the stress
applied to the crack P(x). It is shown that the indicated analytical expressions are bilinear integrals of the functions P(x)
and ∂P(x)/∂x. These integrals are calculated in explicit form for a constant stress over the entire crack length and the stress
due to the action of molecular adhesion forces in a narrow region near the crack openings. It is shown that the calculation
results does not depend on the form of molecular adhesion forces. The proposed approach to describing cracks and calculations
based on it has made it possible for the first time to obtain a complete analytical expression for the limiting crack propagation
velocity in elastic materials as a function of the main mechanical characteristics of such materials.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 4, pp. 158–166, July–August, 2009. 相似文献
12.
We show that the Reissner–Mindlin plate bending model has a wider range of applicability than the Kirchhoff–Love model for
the approximation of clamped linearly elastic plates. Under the assumption that the body force density is constant in the
transverse direction, the Reissner–Mindlin model solution converges to the three-dimensional linear elasticity solution in
the relative energy norm for the full range of surface loads. However, for loads with a significant transverse shear effect,
the Kirchhoff–Love model fails.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
13.
Two-dimensional photoelastic experiments were conducted to obtain isochromatic fringe fields in the region between a crack
tip and a concentrated load on the boundary of a half plane. An analysis method is developed to determine the mixed-mode stress-intensity
factors due to two interacting stress singularities. The results obtained showed the dominance of the opening mode in extending
a delamination crack by sliding surface loads.
Paper was presented at the 1989 SEM Spring Conference on Experimental Mechanics held in Cambridge, MA on May 28–June 1. 相似文献
14.
O. P. Alekseenko A. M. Vaisman A. F. Zazovskii 《Journal of Applied Mechanics and Technical Physics》1998,39(3):454-461
An algorithm that permits one to find a solution of the Perkins-Kern-Nordgren problem for standard regimes of hydraulic fracturing
is suggested. The universal qualitative specifics, of the behavior of a crack is shown; in particular, the asymptotics of
crack opening at the tip is found, and it is shown that the character of the crack is determined by the rate of increase or
decrease in the crack size.
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 3, pp. 149–157, May–June, 1998. 相似文献
15.
G. V. Galatenko 《International Applied Mechanics》2007,43(11):1202-1207
The spatial stress state in a circular plastic zone near an elliptic crack under bi-and tri-axial asymmetric loading at infinity
is studied. It is shown that the plastic constraint factor peaks at the points with maximum external tensile tangential stresses
on the crack boundary. The use of a two-parameter failure criterion leads to the conclusion that the limit state can first
be reached at the ends of the major axis of the elliptic crack depending on the relation between the external stresses
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 11, pp. 24–30, November 2007. 相似文献
16.
L. V. Stepanova 《Journal of Applied Mechanics and Technical Physics》2008,49(1):142-147
This paper discusses the problem of finding the eigenvalue spectrum in determining the stress and strain fields at the tip
of an antiplane-shear crack in a power-law material. It is shown that the perturbation method provides an analytical dependence
of the eigenvalue on the material nonlinearity parameter and the eigenvalue of the linear problem. Thus, it is possible to
find the entire spectrum of eigenvalues and not only the eigenvalue of the Hutchinson-Rice-Rosengren problem.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 1, pp. 173–180, January–February, 2008. 相似文献
17.
V. A. Kovtunenko I. V. Sukhorukov 《Journal of Applied Mechanics and Technical Physics》2006,47(5):704-713
For the evolutionary problem describing crack propagation in a solid with allowance for the irreversible work of plastic deformation
due to the crack propagation, a general optimization formulation is proposed and investigated. For the optimum crack, data
on the H2-smoothnesses of the displacement field in the solid and, hence, on the finiteness of the stress at the crack tip, are obtained.
The solvability of the optimization problem (i.e., the existence of an optimum crack) is proved for a curvilinear crack propagation
path specified a priori. For the particular case of a straight path, a generalized criterion of crack growth is proposed.
The question of the choice of a crack propagation path is discussed and a comparison with existing fracture criteria is made.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 5, pp. 107–118, September–October, 2006. 相似文献
18.
Dynamic crack propagation speeds along the weakly jointed interfaces of PMMA and Homalite-100 were determined experimentally.
These speeds were found to be highly dependent on the bonding strength and on the magnitude of the applied impulsive loads.
As applied loads increase, the maximal speed was found to approach asymptotically the Rayleigh wave velocity of the material.
Paper was presented at the 1985 SEM Spring Conference on Experimental Mechanics held in Las Vegas, NV on June 9–14. 相似文献
19.
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
20.
This paper presents a numerical approach of fatigue growth analysis of cracks emanating from a hole in infinite elastic plate
subjected to remote loads. It involves a generation of Bueckner’s principle and a hybrid displacement discontinuity method
(a boundary element method) proposed recently by the senior author of the paper. Because of an intrinsic feature of the boundary
element method, a general crack growth problem can be solved in a single region formulation. In the numerical simulation,
for each increment of crack extension, remeshing of existing boundaries is not necessary. Crack extension is modeled conveniently
by adding new boundary elements on the incremental crack extension to the previous crack boundaries. As an example, fatigue
growth process of an inclined crack in an infinite plate under uniaxial cycle load is modeled to illustrate the effectiveness
of the numerical approach. In addition, fatigue growth of cracks emanating from a circular hole in infinite elastic plate
subjected to remote loads is investigated by using the numerical approach. Many numerical results are given 相似文献