共查询到20条相似文献,搜索用时 15 毫秒
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Plates are susceptible to buckling under compression when the thickness dimension becomes sufficiently small. Such mode of structure failure can prevail even if the plates were extended in tension. Wribkling of stretched thin sheets is a commonly observed phenomenon that leads to complex deflection patterns, particularly in regions close to crack-like imperfections. Predictions of the buckled displacement modes for plates weakened by cracks will be made on the basis of a theory formulated by application of variational calculus. Finite element method is used such that defects of other shapes can also be analyzed. Various buckled displacement modes of a center-cracked plate are determined and displayed graphically. The critical buckling loads are found to decrease with increasing crack size. Moreover, local wrinkling of the plate surface becomes less pronounced for the higher buckling modes. The method of solution applies equally well to plates that are initially curved. 相似文献
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A simple computer-interfaced optical system for measuring the dynamic-local-buckling deformation of thin-walled metal structural-plate elements is described in this paper with two sets of experimental results. The major advantage of this system is its simplicity and economy as well as its speedy automated process for data scanning, acquisition, and analyses by using a microcomputer.Paper was presented at the 1986 SEM Spring Conference on Experimental Mechanics held in New Orleans, LA on June 8–13. 相似文献
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Scientific Research Institute of Mechanics, Gorky University, Gorky. Translated from Prikladnaya Mekhanika, Vol. 26, No. 5, pp. 43–50, May, 1990. 相似文献
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D. A. Gavrilov V. M. Pestrikov A. V. Pinchuk S. V. Urbanskii 《International Applied Mechanics》1994,30(1):53-57
In [5–7], the influence of the relation between the plate width and the crack length on the limiting load for steel was investigated. The hazardous defect dimension in steel is determined by the grain size, and may be neglected in practice. For molding compositions reinforced by glassfiber or glass-strip sections, the hazardous defect dimension may be comparable with that of a visually observable crack. In that case, the failure criterion and the scale effect for a cracked plate depends on the relation between the plate width and the crack length, and on the crack-resistance characteristic of the material, which is the length of the crack equivalent to the hazardous defect in the material. The aim of the present work is to investigate this characteristic experimentally in various loading conditions, for the example of AG-4V molding composition and to develop a simple model permitting the prediction of the scale effect in analogous materials.S. P. Timoshenko Institute of Mechanics, Ukrainian Academy of Sciences, Kiev. Translated from Prikladnaya Mekhanika, Vol. 30, No. 1, pp. 62–67, January, 1994. 相似文献
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I. A. Banshchikova A. F. Nikitenko 《Journal of Applied Mechanics and Technical Physics》2006,47(5):747-756
The Rabotnov kinetic creep theory was used to calculate the stress-strain state and damage accumulation in the material of
axisymmetrically loaded circular and ring plates at any time before the beginning of fracture. It is shown that the solution
of the problem can be reduced to solving the same problem under the assumption of steady-state creep of the material. The
unsteady creep problem is solved by multiplying the known solution of the steady-state creep problem by certain functions
of the coordinates and time, which are determined from a corresponding system of equations.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 5, pp. 157–168, September–October, 2006. 相似文献
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J. T. Katsikadelis N. G. Babouskos 《Archive of Applied Mechanics (Ingenieur Archiv)》2012,82(10-11):1403-1422
The thickness optimization is used to maximize the stiffness or the buckling load of a Kirchhoff plate having constant volume. The shape of the plate is arbitrary and it is subjected to any type of admissible boundary conditions. The optimization consists in establishing the thickness variation law, for which either the stiffness of the plate or the buckling load is maximized. Beside the equality constraint of constant volume, the thickness variation is subjected also to inequality constraints resulting from serviceability requirements (upper and lower thickness bounds) as well as from the condition that the Kirchhoff plate theory remains valid. The latter constraint is new and it is derived herein by approximating the plate with a three-dimensional prismatic elastic body having curved upper and lower surface. The optimization problem is solved using the sequential quadratic programming algorithm. The bending and the plane stress problem of a plate with variable thickness, required for the evaluation of the objective function, are solved using the analog equation method. The thickness is approximated using integrated radial basis functions that approximate accurately not only the thickness function but also its first and second derivatives involved in the plate equation and in the constraints. Several plate optimization problems have been studied giving realistic and meaningful optimum designs without violating the validity of the thin plate theory. 相似文献
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M. Sh. Dyshel' 《International Applied Mechanics》1999,35(12):1272-1276
An experimental study of the local buckling of plates containing cracks and cracklike defects is reported, where the influence
of the geometrical parameters of the plate and the defect are taken into account. An empirical curve is plotted to estimate
the critical stresses at which buckling takes place.
S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Prikladnaya
Mekhanika, Vol. 35, No. 12, pp. 80–84, December, 1999. 相似文献
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M. Sh. Dyshel' 《International Applied Mechanics》1982,18(10):924-928
Conclusions A method has been developed for analyzing the stability of thin plates with cracks under biaxial tension which is based on measuring the local buckling of the plate in the crack region with pneumatic instruments and describing the results in the system of plate coordinates.It has been demonstrated that the critical stress corresponding to local loss of stability depends strongly on the magnitude of the force acting along the crack. Values of the bending factor have been determined experimentally for plates of the grade AMg6M aluminum alloy. Unlike in the case of no load along the crack, in the case of biaxial loading the value of this bending factor does depend on the geometrical parameters of the plate.An empirical expression has been derived for the bending factor which, for this particular material, yields values close to experimental ones.Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 18, No. 10, pp. 80–85, October, 1982. 相似文献
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Thermal buckling analysis of truss-core sandwich plates 总被引:1,自引:0,他引:1
Truss-core sandwich plates have received much attention in virtue of the high values of strength-to-weight and stifness-to-weight as well as the great ability of impulseresistance recently. It is necessary to study the stability of sandwich panels under the influence of the thermal load. However, the sandwich plates are such complex threedimensional(3D) systems that direct analytical solutions do not exist, and the finite element method(FEM) cannot represent the relationship between structural parameters and mechanical properties well. In this paper, an equivalent homogeneous continuous plate is idealized by obtaining the efective bending and transverse shear stifness based on the characteristics of periodically distributed unit cells. The first order shear deformation theory for plates is used to derive the stability equation. The buckling temperature of a simply supported sandwich plate is given and verified by the FEM. The efect of related parameters on mechanical properties is investigated. The geometric parameters of the unit cell are optimized to attain the maximum buckling temperature. It is shown that the optimized sandwich plate can improve the resistance to thermal buckling significantly. 相似文献