共查询到20条相似文献,搜索用时 15 毫秒
1.
L. I. Shkutin 《Journal of Applied Mechanics and Technical Physics》2008,49(2):330-335
A mathematical formulation is given of nonlinear axisymmetric buckling problems for plates and shells in the two-phase zones
of austenite-to-martensite transformation. Numerical solutions of the direct-and inverse-transformation problems are used
to construct hysteresis loops for thermomechanically cycled, pressure-loaded circular plates and shallow spherical domes of
titanium nickelide (NiTi) alloy. It is shown that dynamic instability of the dome deformation process can occur during transformation under loads notably
lower than the upper critical values for the isothermal states of the material outside the transformation zone. A theoretical
analysis gives external loads below which the dome remains stable in the thermally cycled material with phase transformations.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 2, pp. 204–210, March–April, 2008. 相似文献
2.
L. I. Shkutin 《Journal of Applied Mechanics and Technical Physics》2006,47(2):282-288
The problem of a rod and a plate subjected to plane strain in the interval of the direct phase transformation is formulated
as a nonlinear boundary-value thermoelastic problem with an implicit dependence on temperature (through a phase parameter
simulating the volume fraction of new-phase crystals). An analytical solution of the problem of a rod bent into a ring and
a plate bent into a tube as a result of phase strains under the action of a small end bending moment is given. A numerical
analysis of the buckling problem of a titanium nickelide (alloy) rod (plate) under longitudinal compression in the interval
of the direct phase transformation shows that buckling becomes possible if the compressive load is much lower than the Euler
critical load calculated before the transformation. Branches of buckled equilibrium states corresponding to loads lower than
the Euler load are plotted as functions of the phase parameter. In all cases considered, the deflections increase abruptly
in the neighborhood of the critical points. The evolution of buckling modes is studied, and the phase-strain distributions
along the rod (plate) are shown.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 2, pp. 156–164, March–April, 2006. 相似文献
3.
Dr. inż. P. Klosowski Dr. inż. K. Woźnica Prof. Dr.-Ing. D. Weichert 《Archive of Applied Mechanics (Ingenieur Archiv)》1995,65(5):326-345
Summary In this paper, the problem of the elasto-viscoplastic dynamic behaviour of geometrically non-linear plates and shells is studied under the assumption of small strains and moderate rotations. The Chaboche and Bodner-Partom models were chosen among several types of constitutive laws. To avoid the calculation of the stiffness matrix, an effective procedure using the central difference method of solving the equations of motion was applied. The trapezoidal method was used to integrate the constitutive viscoplastic laws. A nine-node isoparametric shell element was utilised for the finite element algorithm. 相似文献
4.
Starting from the step-by-step iterative method, the analytical formulas of solutions of the geometrically nonlinear equations
of the axisymmetric plates and shallow shells, have been obtained. The uniform convergence of the iterative method, is used
to prove the convergence of the analytical formulas of the exact solutions of the equations. 相似文献
5.
IntroductionTheproblemofdelaminationbucklingofcompositelaminateshasgeneratedsignificantresearchinterestsandhasbeenthesubjectofmanytheoreticalinvestigationsinthisdecade.Afiniteelementmodel[1]waspresentedtosolvethepost_bucklingproblemofcompositeplateswit… 相似文献
6.
The paper proposes a new approach of predicting the bifurcation points of elastic-plastic buckling of plates and shells, which
is obtained from the natural combination of the Lyaponov's dynamic criterion on stability and the modified adaptive Dynamic
Relaxation (maDR) method developed recently by the authors. This new method can overcome the difficulties in the applications
of the dynamic criterion. Numerical results show that the theoretically predicted bifurcation points are in very good agreement
with the corresponding experimental ones. The paper also provides a new means for further research on the plastic buckling
paradox of plates and shells. 相似文献
7.
8.
尹邦信 《应用数学和力学(英文版)》1999,20(7):773-780
IntroductionAscompositesareextensivelyappliedinmodernengineringstructuresandmechanicsofcomplexmaterialshasbenhighlyadvanced,i... 相似文献
9.
H. Altenbach O. Morachkovsky K. Naumenko A. Sychov 《Archive of Applied Mechanics (Ingenieur Archiv)》1997,67(5):339-352
Summary A phenomenological constitutive model for characterization of creep and damage processes in metals is applied to the simulation
of mechanical behaviour of thin-walled shells and plates. Basic equations of the shell theory are formulated with geometrical
nonlinearities at finite time-dependent deflections of shells and plates in moderate bending. Numerical solutions of initial/boundary-value
problems have been obtained for rectangular thin plates (two-dimensional case) and axisymmetrically loaded shells of revolution
(one-dimensional case). Based on the numerical examples for the two problems, the influence of geometrical nonlinearities
on the creep deformation and damage evolution in shells and plates is discussed.
Accepted for publication 30 October 1996 相似文献
10.
The dynamic behavior of reinforced shells of revolution in an elastic medium is modeled. Pasternak’s model is used. A problem
of vibration of discretely reinforced shells of revolution is formulated and a numerical algorithm is developed to solve it.
Results from an analysis of the dynamic behavior of a reinforced spherical shell on an elastic foundation are presented as
an example
Translated from Prikladnaya Mekhanika, Vol. 45, No. 2, pp. 99–106, February 2009. 相似文献
11.
A self-equilibrated stress obtained from the stress functions of thin shells is used for the static shakedown theorem as a residual stress. In combination with the finite element method, a linear programming formulation of the shakedown analysis of axisymmetric shells is derived. The physical meaning of the stress function method is clear and its computing amount is small. Some examples of the plates and shells show that the method is reasonable and efficient.The project was supported by the National Natural Science Foundation of China 相似文献
12.
A dynamic problem for a cylindrical shell on an elastic foundation is formulated. A numerical algorithm for solving this problem
is outlined. The results obtained are analyzed
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 12, pp. 103–109, December 2007. 相似文献
13.
在均布外压作用下复合材料三角形网格加筋圆锥壳体总体稳定性分析 总被引:1,自引:0,他引:1
本文在文献[1]的基础上加以推广,分析了在均布外压作用下复合材料三角形网格加筋圆锥壳体总体稳定性,考虑了蒙皮的正交拉弯耦合效应和加筋筋条的偏心效应.基于外压实验观察结果,通过选择恰当的位移分量表达式,本文利用Galerkin法获得了临界外压的近似表达式,并对某一C/E复合材料三角形内网格加筋圆锥壳体的临界外压值进行了理论计算,所得结果与实验值相当吻合.文中所得结果可供工程应用参考. 相似文献
14.
复合材料层合板的二次屈曲和二次分枝点分析 总被引:1,自引:0,他引:1
为了研究复合材料层合板的二次分叉特性 ,利用能量变分原理和非线性几何方程建立了具有弹性约束的复合材料层合板在面内载荷作用下的非线性稳定性控制方程组。控制方程组用广义傅立叶级数法进行求解 ,并得到载荷 -挠度曲线。基于分叉理论中的 Lerray-Schaulder定理 ,采用小挠动法 ,直接导出了复合材料层合板的二次失稳方程。研究结果表明 ,非对称层板也可能存在分叉 ,弹性转动支持系数和铺层等因素对二次分叉有很重要的影响。随着弹性系数的增大 ,二次失稳载荷值与初次失稳载荷值之比下降 相似文献
15.
A solution is obtained that describes the postbuckling behavior of cylindrical shells in the case of axisymmetric buckling.
The basis for this solution is Koiter’s asymptotic method and the nonlinear equations of the third-order Timoshenko theory
of shells. It is shown that the bifurcation point in this case is a symmetrically unstable one. The effect of the initial
axisymmetric deflections on the buckling loads is weaker when buckling is axisymmetric. The results obtained by Koiter’s special
theory evidence this
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 4, pp. 108–118, April 2006. 相似文献
16.
This paper presents a general solution of the three-dimensional governing equations for the axisymmetric buckling problem of transversely isotropic media. The solution is expressed by a displacement function that satisfies a homogeneous fourth-order partial differential equation. Using this general solution, the axisymmetric buckling of circular and annular plates is investigated and exact solutions are obtained for appropriate boundary conditions. Numerical results are considered for clamped and simply supported circular and annular plates in comparison with existent results. 相似文献
17.
18.
R. Naghdabadi S. A. Hosseini Kordkheili 《Archive of Applied Mechanics (Ingenieur Archiv)》2005,74(5-6):375-386
Summary A finite element formulation is derived for the thermoelastic analysis of functionally graded (FG) plates and shells. The
power-law distribution model is assumed for the composition of the constitutent materials in the thickness direction. The
procedure adopted to derive the finite element formulation contains the analytical through-the-thickness integration inherently.
Such formulation accounts for the large gradient of the material properties of FG plates and shells through the thickness
without using the Gauss points in the thickness direction. The explicit through-the-thickness integration becomes possible
due to the proper decomposition of the material properties into the product of a scalar variable and a constant matrix through
the thickness. The nonlinear heat-transfer equation is solved for thermal distribution through the thickness by the Rayleigh-Ritz
method. According to the results, the formulation accounts for the nonlinear variation in the stress components through the
thickness especially for regions with a variation in martial propperties near the free surfaces. 相似文献
19.
20.
The effect of axisymmetric dents in ribbed shells on the minimum critical loads is studied analytically. The upper and lower
bounds for the critical stresses in imperfect cylindrical shells reinforced with stringers, rings, and both are estimated.
The upper bounds are compared with those obtained from the known solutions for perfect ribbed momentless shells and with experimental
data. The effect of the amplitude of initial dents and their number on the upper and lower bounds of critical stresses is
examined. The procedure used is the most efficient to determine the load-bearing capacity of ring-reinforced and ribbed shells
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 5, pp. 73–79, May 2007. 相似文献