共查询到20条相似文献,搜索用时 46 毫秒
1.
An approach is proposed to solve boundary-value stress—strain problems for cylindrical shells with thickness varying in two
coordinate directions. The approach employs discrete Fourier series to separate circumferential variables. This makes it possible
to reduce the problem to a one-dimensional one, which can be solved by the stable discrete-orthogonalization method. Examples
are given
__________
Translated from Prikladnaya Mekhanika, Vol. 41, No. 6, pp. 85–94, June 2005. 相似文献
2.
The behavior of elastoplastic threads of finite stiffness under lateral bending is analyzed. Geometrical and physical nonlinearities
are taken into account. The material is assumed to be elastoplastic. The nonlinear equations describing the stress—strain
state of threads are derived using the virtual-displacement principle. Numerical results are discussed
__________
Translated from Prikladnaya Mekhanika, Vol. 41, No. 6, pp. 121–129, June 2005. 相似文献
3.
A. Ya. Grigorenko O. V. Vovkodav S. N. Yaremchenko 《International Applied Mechanics》2012,48(1):80-93
The stress–strain state of an orthotropic spherical shell with thickness varying in two coordinate directions is analyzed.
Different boundary conditions are considered, and a refined problem statement is used. A numerical analytic method based on
spline-approximation and discrete orthogonalization is developed. The stress–strain state of spherical orthotropic shells
with variable thickness is studied 相似文献
4.
Two approaches to the analysis of the stress–strain state of thick cylindrical shells are elaborated. The shell is divided
by concentric cross-sectional circles into several coaxial cylindrical shells. Each of these shells has its own curvature
determined on its midline. The stress–strain state of the original shell is described by satisfying the interface conditions
between the component shells. The distribution of unknown functions throughout the thickness is determined by finding the
analytic solution of a system of differential equations in the first approach and is approximated by polynomial functions
in the second approach. The stress–strain state of thick shells is analyzed. It is revealed that the effect of reduction becomes
stronger with increasing curvature 相似文献
5.
A technique is proposed to allow for deformation damage of cylindrically orthotropic elastic materials in a thermoelastoplastic stress–strain analysis of composite bodies of revolution under nonaxisymmetric loading and heating 相似文献
6.
E. A. Gotsulyak O. K. Luk’yanchenko E. V. Kostina I. G. Garan 《International Applied Mechanics》2011,47(3):302-312
A finite-element method to analyze the stress–strain state and stability of thin shells with geometric imperfections is proposed.
An arbitrary curvilinear finite element with vector approximation of the displacement function is used. To solve the systems
of nonlinear algebraic equations by iteration methods, linearized stiffness matrices of finite elements and residual and load
vectors are formed. The stress–strain state of a thin-walled shell with real geometric imperfections under surface pressure
and axial compression is analyzed. The effect of geometric imperfections on the critical combination of loads is evaluated 相似文献
7.
A refined Timoshenko-type model based on the straight-line hypothesis is used to develop an approach to analyzing the stress
state of longitudinally corrugated cylindrical shells with elliptic cross-section. The approach is to reduce the two-dimensional
boundary-value problem that describes the stress–strain state of the shell to a one-dimensional one and to solve it with the
stable numerical discrete-orthogonalization method. The solutions obtained using the straight-line hypothesis and the equations
of three-dimensional elasticity are compared. The dependence of the stress–strain state of the shell on the number and amplitude
of corrugations and the aspect ratio of the cross-section is analyzed 相似文献
8.
A method for numerical analysis of the elastoplastic stress–strain state of thin layered shells of revolution under axisymmetric
loading is proposed. Constitutive equations describing the elastoplastic deformation of isotropic materials with allowance
for the stress mode are used. Numerical results are presented 相似文献
9.
The elastoplastic state of thin spherical shells with an elliptic hole is analyzed considering that deflections are finite.
The shells are made of an isotropic homogeneous material and subjected to internal pressure of given intensity. Problems are
formulated and a numerical method for their solution with regard for physical and geometrical nonlinearities is proposed.
The distribution of stresses (strains or displacements) along the hole boundary and in the zone of their concentration is
studied. The results obtained are compared with the solutions of problems where only physical nonlinearity (plastic deformations)
or geometrical nonlinearity (finite deflections) is taken into account and with the numerical solution of the linearly elastic
problem. The stress—strain state in the neighborhood of an elliptic hole in a shell is analyzed with allowance for nonlinear
factors
__________
Translated from Prikladnaya Mekhanika, Vol. 41, No. 6, pp. 95–104, June 2005. 相似文献
10.
An experimental study is undertaken to examine the dynamic stress–strain characteristics of ligaments from the human cervical
spine (neck). Tests were conducted using a tensile split Hopkinson bar device and the engineering strain rates imposed were
of the order of 102∼103/s. As ligaments are extremely soft and pliable, specialized test protocols applicable to Hopkinson bar testing were developed
to facilitate acquisition of reliable and accurate data. Seven primary ligaments types from the cervical spines of three male
cadavers were subjected to mechanical tests. These yielded dynamic stress–strain curves which could be approximated by empirical
equations. The dynamic failure stress/load, failure stain/deformation, modulus/stiffness, as well as energy absorption capacity,
were obtained for the various ligaments and classified according to their location, the strain rate imposed and the cadaveric
source. Compared with static responses, the overall average dynamic stress–strain behavior foreach type of ligament exhibited
an elevation in strength but reduced elongation. 相似文献
11.
International Applied Mechanics - A technique of numerical analysis of the elastoplastic axisymmetric stress–strain state of thin isotropic shells with different tensile and compressive... 相似文献
12.
In the present study a new insert design is presented and validated to enable reliable dynamic mechanical characterization
of low strain-to-failure materials using the Split-Hopkinson Pressure Bar (SHPB) apparatus. Finite element-based simulations
are conducted to better understand the effects of stress concentrations on the dynamic behavior of LM-1, a Zr-based bulk metallic
glass (BMG), using the conventional SHPB setup with cylindrical inserts, and two modified setups—one utilizing conical inserts
and the other utilizing a “dogbone” shaped specimen. Based on the results of these computational experiments the ends of the
dogbone specimen are replaced with high-strength maraging steel inserts. This new insert-specimen configuration is expected
to prevent specimen failure outside the specimen gage section. Simulations are then performed to validate the new insert design.
Moreover, high strain-rate uniaxial compression tests are conducted on LM-1 using the modified SHPB with the new inserts.
An ultra-high-speed camera is employed to investigate the changes in failure behavior of the specimens. Additional experiments
are conducted with strain gages directly attached to the gage section of the specimens to determine accurately their dynamic
stress–strain behavior. 相似文献
13.
Methods and results of studies of the three-dimensional viscoplastic stress–strain state of engineering structures under thermomechanical loading are presented. The following classes of thermoviscoplastic problems are considered: axisymmetric problems, nonaxisymmetric problems for bodies of revolution, three-dimensional problems for bodies of arbitrary shapes, and three-dimensional problems for anisotropic bodies of revolution 相似文献
14.
The paper proposes a method, based on perfect-plasticity and perturbation theories, for instability analysis of an annular
flat disk tightly set on a shaft with no interference fit. The perturbed elastoplastic state of the rotating disk is analyzed
by determining the stress–strain state of a fixed elastic annular plate under in-plane loading. A characteristic equation
of the first order for the critical radius of the plastic zone in the disk subject to internal pressure is derived. The critical
rotation rate is calculated for different parameters of the disk 相似文献
15.
Jeremiah G. Murphy 《Journal of Elasticity》2007,86(2):139-154
The form of the classical stress–strain relations of linear elasticity are considered here within the context of nonlinear
elasticity. For both Cauchy and symmetric Piola-Kirchhoff stresses, conditions are obtained for the associated strain fields
so that they are independent of the material constants and compatible with existence of a strain–energy function. These conditions
can be integrated in both cases to obtain the most general strain field that satisfies these conditions and the corresponding
strain–energy function is obtained. In both cases, a natural choice of form of solution is suggested by the special case of
the compatibility conditions being satisfied identically. It will be shown that some strain–energy functions previously introduced
in the literature are special cases of the results obtained here. Some recent linear stress–strain relations, proposed in
the context of Cauchy elasticity, are examined to see if they are compatible with hyperelasticity.
相似文献
16.
The paper outlines a procedure for the numerical analysis of the thermoelastoplastic stress–strain state of thin compound
shells of revolution under axisymmetric nonisothermal loading. The constitutive equations describing the thermoelastoplastic
deformation of isotropic materials along paths of small curvature and incorporating the third invariant of the stress deviator
are used. A numerical example is presented 相似文献
17.
A technique for nonaxisymmetric thermoelastoplastic stress–strain analysis of laminated shells of revolution is developed. It is assumed that there is no slippage and the layers are not separated. The problem is solved using the geometrically linear theory of shells based on the Kirchhoff–Love hypotheses. The thermoplastic relations are written down in the form of the method of elastic solutions. The order of the system of partial differential equations obtained is reduced by means of trigonometric series in the circumferential coordinate. The systems of ordinary differential equations thus obtained are solved by Godunov's discrete-orthogonalization method. The nonaxisymmetric thermoelastoplastic stress–strain state of a two-layered shell is analyzed as an example 相似文献
18.
Microdeformation patterns of lamellar TiAl specimens with various grain sizes under uniaxial tension are mapped using the
micro/nano experimental mechanics technique called SIEM (Speckle Interferometry w ith Electron Microscopy). The stress–strain
relationships were obtained from deformations within decreasing areas ranging from mm2 to μm2. We found that the stress–strain relationship of the material depends on the size of strain measuring area in relation to
the grain size. The stiffness at a grain boundary can be as large as 7–10 times more than that of the grain itself. From the
data obtained so far, it seems that the traditional way of using PST (polysynthetically twinned) single crystal to predict
polycrystalline behavior may not be appropriate. 相似文献
19.
Lugovyi P. Z. Gaidaichuk V. V. Skosarenko Yu. V. Kotenko K. E. 《International Applied Mechanics》2021,57(4):395-404
International Applied Mechanics - The stress–strain state of symmetric three-layer cylindrical shells under nonstationary loads is considered. The equation of vibrations of a shell with a... 相似文献
20.
Gulyaev V. I. Gaidaichuk V. V. Chernyavskii A. G. Scialino L. 《International Applied Mechanics》2003,39(9):1084-1088
A structural analysis of a large orbital antenna is reduced to stress–strain, stability, and modal analyses of its prestressed structure. The numerical results obtained by the finite-element method are presented 相似文献