The uniform heating and bending of a two-layer plate

The problem of the uniform heating of a two-layer plate is solved. The transversely isotropic layer considered (a soft plate) is in ideal contact with a rigid isotropic thin elastically deformed layer. The ends of the plate are load-free. A boundary layer of the soft plate (a thin contact layer) is introduced, which enables the boundary conditions on the ends of the plate to be formulated in such a way that the problem has a bounded smooth solution [1]. The two-layer plate, generally speaking, is bounded along the axis perpendicular to the axes directed along the length and thickness of the plate. The resultant force and the resultant moment, applied to the end transverse sections, are equal to zero. The exact solution of the temperature problem is sought using the equations of the theory of elasticity. The plane problem of the bending of a two-layer plate acted upon by a uniformly distributed pressure applied to the side surface of an anisotropic layer is solved by a similar method. The ends of the rigid isotropic layer are clamped.     

Buckling analysis of a ring under the action of internal pressure in a cylindrical shell

Buckling analysis of a thin cylindrical shell stiffened by rings with T-shaped cross section under the action of uniform internal pressure in the shell is performed. An annular plate stiffened over the outer edge by a circular beam is used as the ring model. The classical ring model, which is a beam with a T-shaped cross section, is inappropriate in this problem, since in the case of the loss of stability, buckling deformations are localized on the ring surface. The beam model does not allow one to find the critical pressure that corresponds to such a loss of stability. In the first approximation, the problem of the loss of stability of the annular plate connected with the shell is reduced to solving the boundary value problem for finding eigenvalues of the annular plate bending equation. Approximate formulas for determining critical pressure are obtained under the assumption that the plate width is much smaller than its inner radius. The results found using the Rayleigh method and the shooting method differ slightly from each other. It has been demonstrated that the critical pressure for rings with rectangular cross section is higher than that for rings with a T-shaped cross section.     

A problem of the bending of a plate for a doubly connected domain with a partially unknown boundary

The problem of the bending of an isotropic elastic plate, bounded by two rectangles with vertices lying on the same half-line, drawn from the common centre, is considered. The vertices of the inner rectangle are cut by convex smooth arcs (we will call the set of these arcs the unknown part of the boundary). It is assumed that normal bending moments act on each rectilinear section of the boundary contours in such a way that the angle of rotation of the midsurface of the plate is a piecewise-constant function. The unknown part of the boundary is free from external forces. The problem consists of determining the bending of the midsurface of the plate and the analytic form of the unknown part of the boundary when the tangential normal moment acting on it takes a constant value, while the shearing force and the normal bending moments and torques are equal to zero. The problem is solved by the methods of the theory of boundary-value problems of analytical functions.     

Model for Contact of Crack Boundaries in a Bending Plate

Closed cracks in a bending plate are studied in a two-dimensional formulation based on the Kirchhoff theory and the theory of the two-dimensional stressed state. A generalization of the end contact model is discussed which makes it possible formulate a geometrically linear contact bending problem for a plate with a rectilinear cut including the interaction of symmetric and antisymmetric deformation modes. A procedure for reducing the problem to a system of singular integral equations is described. An example of the calculations is given.     

On bending an elastic plate with a delaminated thin rigid inclusion

Under study is the problem of bending an elastic plate with a thin rigid inclusion which may delaminate and form a crack. We find a system of boundary conditions valid on the faces of the crack and prove the existence of a solution. The problem of bending a plate with a volume rigid inclusion is also considered. We establish the convergence of solutions of this problem to a solution to the original problem as the size of the volume rigid inclusion tends to zero.     

The bending equations of sandwich plates with a prestressed filling

An approximate model of the linear bending of an orthotropic sandwich plate is proposed, taking into account the excess pressure in the space of the filling and the difference in the areas of the surfaces of the elastically curved supporting layers, and the dependence of the shear modulus of the filling on the pressure is postulated. The bending equations of the plate are also given, taking into account the external excess pressure. The value of the transverse distributed force acting on the plate due to the excess pressure in the space of the middle layer and the curvature of the elastic line is obtained. It is shown that this pressure leads to an increase in the bending. If the space of the filling is closed, so that stretching forces due to the pressure act on the boundary sections, the bending is independent of the pressure drop. The dependence of the distributed transverse force on the external pressure is derived. The change in the shear modulus of the filling as a function of the external pressure drop is also considered.     

纯扭各向异性复合材料板断裂分析的复变函数方法

对受纯扭载荷作用的线弹性各向异性纤维复合材料板裂纹尖端附近的应力场进行探讨.选取带复参数的挠度函数,利用复变函数方法和待定系数法,借助边界条件,确定复参数,从而推出了裂纹尖端附近的弯矩、扭矩、应力和位移计算公式.所得到的公式在有关的断裂分析中有一定的实用价值和参考作用,最后给出了数值算例.     

A contact problem for an elastic plate with a thin rigid inclusion

Under study is an equilibrium problem for a plate under the influence of external forces. The plate is assumed to have a thin rigid inclusion that reaches the boundary at the zero angle and partially contacts a rigid body. On the inclusion face, there is a delamination. We consider the complete Kirchhoff–Love model, where the unknown functions are the vertical and horizontal displacements of the middle surface points of the plate. We present differential and variational formulations of the problem and prove the existence and uniqueness of a solution.     

The bending of a circular membrane on a linearly deformed foundation

The axisymmetric problem of the bending of a circular transversely-loaded membrane (i.e., a thin plate having no flexural stiffness), which lies without friction on a linearly deformed foundation, where there is contact over the whole area of the membrane, is considered. The problem is reduced to the combined investigation of a differential equation for the bending of the membrane and an integral equation of the first kind with an irregular kernel in the unknown contact pressure. The method of special orthonormalized polynomials and the regular asymptotic “large λ” method are used to solve the problem.     

Boundary integral equations for bending of thermoelastic plates with transmission boundary conditions

The solution of an initial‐boundary value problem for bending of a piecewise‐homogeneous thermoelastic plate with transverse shear deformation is represented as various combinations of single‐layer and double‐layer time‐dependent potentials. The unique solvability of the boundary integral equations generated by these representations is proved in spaces of distributions. Copyright © 2009 John Wiley & Sons, Ltd.     

Action of a concentrated load on an elastic ring pressed into a circular hole in an anisotropic plate

A solution is obtained for the elastic equilibrium problem for an anisotropic plate with a circular hole into which is pressed a ring of arbitrary cross section symmetrical about the middle surface of the plate. Before deformation the outside radius of the ring differs from the radius of the hole in the plate by the amount of the permissible elastic displacements. A normal concentrated load is applied to the ring. The ring is analyzed in accordance with the theory of thin curved bars. A numerical example is given.I. Franko L'vov State University. Translated from Mekhanika Polimerov, No. 6, pp. 1054–1059, November–December, 1973.     

Vibrations of an annular plate under the influence of a force rotating at a constant velocity

An exact solution is obtained for a dynamic problem concerning the bending of circular and annular plates under the influence of a force rotating at a constant angular velocity. It is shown that this problem is related to the problem of the bending of a plate under the influence of a harmonic load. Velocities leading to resonance are found and their first values are calculated for circular hinged and rigidly fastened plates.Translated from Dinamicheskie Sistemy, No. 4, pp. 62–65, 1985.     

应用虚拟功的互等定理求解均载悬臂厚矩形板的弯曲

悬臂矩形板的弯曲问题一直是平板经典理论中的著名难题,利用中厚板虚拟功的互等定理,借助付宝连提出的角点静力边界条件,得到了均布载荷作用下悬臂厚矩形板弯曲的封闭解析解,并采用现代数值方法和计算软件对所得解析解进行了数值计算.结果表明功的互等法是求解中厚板弯曲问题的一个简明有效的方法.     

集中载荷作用下层合厚圆板的轴对称弯曲

从三维弹性力学基本方程出发,建立了横观各向同性层合圆板轴对称弯曲问题的状态方程,并将板面的集中载荷展成付里叶贝塞尔级数,从而给出问题的解析解,此解满足弹性力学全部方程,计及了所有独立的弹性常数,并满足层间连续性条件。     

Solution of the bending problem of a circular plate with a free edge by using paired equations

Used in the investigation of the bending of a plate with a free edge is a method including the solution of non-standard paired equations that are trigonometric series, which results in a quasi-completely-regular system of linear algebraic equations. The nature of the plate state of stress and strain is investigated. One of the methods reducing to the solution of paired summation equations is elucidated in /1/ in application to the problem under consideration. A combination of support and clamping is examined in the majority of papers while the case of the free edge is inadequately studied.     

Calculation of rigidly clamped circular plates in the statement of the problem on contact interaction in a two-layer package

The use of a mechanicomathematical model of bending of thick transversely isotropic plates is illustrated, where the plate is divided in an arbitrary number of equally thick conditional layers. This model allows one to approximately reduce the problem of determination of stresses and displacements in the thick plate to a corresponding contact problem for a bent pack age of layers. The axisymmetric bending of a rigidly clamped package consisting of two plates rigidly fastened together is considered. The results of numerical calculations are presented, which are compared with those obtained within the framework of a refined bending model of plates (with account of transverse compression and shear) and of the Timoshenko model, as well as in the statement of the three-dimensional theory of elasticity. The accuracy of satisfying the boundary conditions in each model is analyzed. __________ Translated from Mekhanika Kompozitnykh Materialov, Vol. 43, No. 1, pp. 93–108, January–February, 2007.     

On the optimal design of plates for a given deflection

The optimum design problem of an elastic plate for a given deflection is considered. The design variable is chosen to be the thickness of the plate. Using the principle of stationary mutual potential energy first introduced by Shield and Prager, a sufficient optimality condition (which makes the volume stationary) is derived for plates under bending caused by general loading conditions. As an example, the optimum profile of a simply supported circular plate under a given rotationally symmetric loading is obtained.     

Mixed Boundary Value Problem of Plate Bending

The bending problem of thin plates is presented through biharmonic equations expressed in terms of plate deflections. The theory of analytical functions is used to transform the problem to the Hilbert boundary value problem. The stress and deformation state of the plate is descibed by analitical functions which satisfy mixed boundary conditions. A circular plate with corresponded boundary conditions is treated.     

Bending of a developable surface that preserves its edge and generators

We consider the problem of reconstructing a piecewise smooth developable surface with a curvilinear edge from its development on which the preimages of the curvilinear edge and all rectilinear generators of the surface that emanate from the points of this edge are given. The required developable surface admits a one-parameter bending in the ambient Euclidean 3-space, and this bending is presented explicitly by formulas.     

板弯曲问题的具两组高阶基本解序列的MRM方法

讨论了双参数地基上薄板弯曲问题.利用两组高阶基本解序列,即调和及重调和基本解序列,采用多重替换方法(MRM方法),得到了板弯曲问题的MRM边界积分方程.证明了该方程与边值问题的常规边界积分方程是一致的.因此由常规边界积分方程的误差估计即可得到板弯曲问题MRM方法的收敛性分析.此外该方法还可推广到具多组高阶基本解序列的情形.