共查询到20条相似文献,搜索用时 15 毫秒
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Physically and geometrically nonlinear two-dimensional problems are formulated for multiply connected thin shells (weakened by several curvilinear holes). A technique and algorithm are proposed for their solution with allowance for elastoplastic strains and finite deflections of shells under static loading. Numerical results for a shell with two circular holes are presented and the stress concentration is analyzed 相似文献
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Hydrostatic loading causes an isotropic elastic solid to be in a state of pure dilatation with no distortion relative to its
unstressed reference configuration. Similarly, hydrostatic loading causes a general orthotropic solid to be distorted relative
to its unstressed reference configuration. This paper introduces physically based invariants for orthotropic nonlinear elastic
solids which are measures of distortions that cause deviatoric Cauchy stress. Specifically, these invariants allow for the
modeling of the distortion in a hydrostatic state of stress independently of the form of the strain energy function. Consequently,
use of these invariants may lead to simpler forms of the strain energy function which adequately model specific orthotropic
solids.
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V. A. Maksimyuk 《International Applied Mechanics》2001,37(12):1602-1606
An analogy is established between some terms of the functionals under consideration and the formulas of the theory of random processes. On this basis, the efficiency of mixed functionals is attributed to a deeper minimum they help to reach by taking the energy of so-called false strains into consideration. We perform a numerical stress—strain analysis of an organoplastic cylindrical shell with a side circular hole and study how the orthotropy and nonlinear properties of the composite affect the stress distribution near the hole. The case is discovered where the orientation of the composite about the cylindrical shell changes so that a larger nonlinear effect corresponds to a smaller initial stress 相似文献
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考虑面层横向剪切变形以及横向剪应力在面层和芯层粘结处连续,应用Hamilton原理建立了正交铺设复合材料面层夹层扁壳新的非线性精化理论。在静力问题情形,控制方程和边界条件化简为用四个基本未知函数表述。作为理论的应用,分析了简支边界条件下正交铺设复合材料面层夹层圆柱壳和夹层球壳的非线性弯曲,得到了其挠度响应和层间应力响应。 相似文献
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A technique is developed to determine the axisymmetric, geometrically nonlinear, thermoplastic stress–strain state of laminated ortotropic shells of revolution under loads that cause a meridian stress state and torsion. The technique is based on the rectilinear-element hypotheses for the whole stack of layers. The active elastoplastic deformation of an ortotropic material is described by deformation-type equations that have been derived without resort to the existence conditions for the plastic potential. The scalar functions in the constitutive equations depend on the intensity of shear strains and temperature. The problem is solved through the numerical integration of a system of differential equations. The technique is tried out in designing tubular specimens subjected to axial force and torque. As an example, the elastoplastic state of a corrugated shell is analyzed 相似文献
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Abrosov Yu. Yu. Maximyuk V. A. Chernyshenko I. S. 《International Applied Mechanics》2021,57(3):282-289
International Applied Mechanics - The stress–strain state of long cylindrical shells with elliptical cross-section is studied. The shells are made of a nonlinear elastic orthotropic organic... 相似文献
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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
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Translated from Prikladnaya Mekhanika, Vol. 41, No. 6, pp. 95–104, June 2005. 相似文献
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Study is made of how the nonlinear properties of orthotropic composites and the ellipticity of an opening affect the stress–strain state of thin spherical shells subjected to internal pressure. An analysis of numerical results reveals compression on the inside surface of the shell near the broad of the elliptical opening. It is pointed out that as the ellipticity increases, the deformation process near the opening transforms from uniform tension and bending, typical of a shell with a circular opening, to dominated tension near the narrow of the opening and to dominated bending near the broad. 相似文献
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V. S. Pavlovskii 《International Applied Mechanics》2000,36(10):1369-1379
The nonlinear resonance vibrations and stability of nonlinear orthotropic shells partially filled with a liquid and subjected to longitudinal and transverse periodic loading are studied. The equations of motion are derived with regard for the existence and nonlinear interaction of conjugate flexural modes of the shell. Stationary regimes for forced and parametric vibrations are found and analyzed for stability under the conditions of fundamental and subharmonic resonances. The amplitude–frequency characteristics of these regimes are constructed for various parameters of the system 相似文献
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A technique for stability analysis of cylindrical shells with a corrugated midsurface is proposed. The wave crests are directed along the generatrix. The relations of shell theory include terms of higher order of smallness than those in the Mushtari–Donnell–Vlasov theory. The problem is solved using a variational equation. The Lamé parameter and curvature radius are variable and approximated by a discrete Fourier transform. The critical load and buckling mode are determined in solving an infinite system of equations for the coefficients of expansion of the resolving functions into trigonometric series. The solution accuracy increases owing to the presence of an aggregate of independent subsystems. Singularities in the buckling modes of corrugated shells corresponding to the minimum critical loads are determined. The basic, practically important conclusion is that both isotropic and orthotropic shells with sinusoidal corrugation are efficient only when their length, which depends on the waveformation parameters and the geometric and mechanical characteristics, is small 相似文献
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Some approaches to the solution of problems on the elastic deformation of thin-walled solids with a complex shape are analyzed on the basis of linear and geometrically nonlinear models. The general characteristic of the classical approaches to the solution of the problems is discussed. Approaches employing new classes of surfaces are considered. Solutions to some problems on the stress state of complex shell elements are presented 相似文献
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I. Yu. Khoma 《International Applied Mechanics》2000,36(8):1077-1087
The expansion of functions into Fourier series in terms of Legendre polynomials is used to state some relations of the geometrically nonlinear theory of nonthin anisotropic shells with a variable thickness. A system of equilibrium equations and corresponding boundary conditions are constructed 相似文献
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Yu. N. Nemish 《International Applied Mechanics》2000,36(9):1150-1180
The three-dimensional physically nonlinear elastic problems solved mainly at the S. P. Timoshenko Institute of Mechanics of the National of Academy Sciences of Ukraine are systematized. In this area, efficient approximate analytical methods were developed to solve boundary-value problems for homogeneous and piecewise-homogeneous nonlinearly elastic bodies of canonical and noncanonical shapes. They are used to analytically solve specific problems with the necessary accuracy and to reveal characteristic mechanical effects 相似文献
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