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The problem of the stability of anisotropic cylindrical shells is numerically solved in a three-dimensional statement. The shells are made of a material with one plane of elastic symmetry. By using the Bubnov-Galerkin method to approximate unknown functions with respect to the longitudinal coordinate by trigonometric series, the problem is reduced to a one-dimensional one that is solved by the discrete-orthogonalization method. The results are tested. [ABSTRACT FROM AUTHOR]

The buckling analysis of anti-symmetric cross-ply laminated composite plates under different boundary conditions is examined by using a refined higher order exponential shear deformation theory. The theory, which has strong similarity with classical plate theory in many aspects, accounts for a quadratic variation of the transverse shear strains across the thickness and satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using shear correction factors. The number of independent unknowns in the present theory is four, as against five in other shear deformation theories. In this investigation, the equations of motion for simply supported thick laminated rectangular plates are derived and obtained through the use of Hamilton's principle. The closed-form solutions of anti-symmetric cross-ply and angle-ply laminates are obtained using Navier solution. Numerical results for critical buckling loads anti-symmetric cross-ply laminated composite plates are presented. The validity of the present study is demonstrated by comparison with other higher-order solutions reported in the literature. It can be concluded that the proposed theory is accurate and simple in solving the buckling behaviors of anti-symmetric cross-ply laminated composite plates under different boundary conditions [ABSTRACT FROM AUTHOR]

An approach to solving the problem of the nonlinear deformation of orthotropic cylindrical shells is proposed. On the surface of the shell, there is a local deflection bounded by segments of the coordinate lines. The Timoshenko-Mindlin shell theory, the Byskov-Hatchinson asymptotic method, and the continuous continuation method for solving nonlinear algebraic equations are used. To determine the critical loads and deformation paths, it is necessary to estimate the number of interacting modes sufficient to achieve satisfactory accuracy. Examples of analyzing composite shells with an initial local deflection of positive or negative amplitude are given [ABSTRACT FROM AUTHOR]

A procedure for analytical solution of the problem of the stability and post-buckling behavior of orthotropic cylindrical shells under external pressure or axial compression with allowance for transverse shears is developed. The shells are geometrically imperfect due to the presence of a local deflection. The problem is solved by analyzing the interaction of the modes that represent the critical loads of the perfect shell and using the Byskov-Hutchinson method. Equilibrium curves for both shells are plotted using the method of continuous loading [ABSTRACT FROM AUTHOR]

The buckling of elastic circular plates with an internal elastic ring support and elastically restrained edges against rotation and simply supported is concerned. The classical plate theory is used to derive the governing differential equation. This work presents the existence of buckling mode switching with respect to the radius of internal elastic ring support. The plate may buckle in an axisymmetric mode in general, but when the radius of the ring support becomes small, the plate may buckle in an asymmetric mode. The cross-over ring support radius varies from 0.09891 to 0.1545 times the plate radius, depending on the rotational stiffness of the elastic restraint at the edges and elastic restraint of the ring. The optimum radius of the internal elastic ring support for maximum buckling load is also determined. Extensive data is tabulated so that pertinent conclusions can be arrived at on the influence of rotational restraint, translational restraint of internal elastic ring support, Poisson's ratio, and other boundary conditions on the buckling of uniform isotropic circular plates. The numerical results obtained are in good agreement with the previously published data [ABSTRACT FROM AUTHOR]

An incremental approach to the statement and solution of the problem of the nonlinear deformation of shells under loads that cause buckling and strong bending in the plastic range is developed. The relations between strains and displacements for great angles of rotation are used. A system of differential equations for the rates of the unknown functions is derived and represented in Cauchy operator form. To solve the boundary-value problem, the discrete-orthogonalization method is used assuming that the unknown functions and the loads are equivalent. The problem of the buckling and postbuckling behavior of a long D16T-alloy shell with a local initial deflection is solved as an example [ABSTRACT FROM AUTHOR]

In this study, out-of-plane stability analysis of tapered cross-sectioned thin curved beams under uniformly distributed radial loading is performed by using the finite-element method. Solutions referred to as Bolotin's approach are analysed for dynamic stability, and the first unstable regions are examined. Out-of-plane vibration and out-of-plane buckling analyses are also studied. In addition, the results obtained in this study are compared with the published results of other researchers for the fundamental frequency and critical lateral buckling load. The effects of subtended angle, variations of cross-section, and dynamic load parameter on the stability regions are shown in graphics [ABSTRACT FROM AUTHOR]

The paper outlines the fundamentals of the method of solving static problems of geometrically nonlinear deformation, buckling, and postbuckling behavior of thin thermoelastic inhomogeneous shells with complex-shaped midsurface, geometrical features throughout the thickness, or multilayer structure under complex thermomechanical loading. The method is based on the geometrically nonlinear equations of three-dimensional thermoelasticity and the moment finite-element scheme. The method is justified numerically. Results of practical importance are obtained in analyzing poorely studied classes of inhomogeneous shells. These results provide an insight into the nonlinear deformation and buckling of shells under various combinations of thermomechanical loads. [ABSTRACT FROM AUTHOR]

Investigations of viscoelastic composite materials and structural members carried out using the TDLTSDB and initial-imperfection method are reviewed. The investigations address the internal and surface loss of stability of layered and fibrous composites, the loss of stability of plates, and the delamination (buckling) of plates with cracks. Each of these problems is reviewed separately. New areas of further research are proposed. The review focuses on the investigations carried out by the author and his students [ABSTRACT FROM AUTHOR]

The axisymmetric buckling (delamination) of a circular disk (plate) with a penny-shaped crack is analyzed using a continuum model, piecewise-homogeneous model, and the three-dimensional linearized theory of stability. The FEM is used. The analysis is carried out using various singular and ordinary finite elements. The numerical results obtained indicate that it is not necessary to use singular finite elements to solve the problem [ABSTRACT FROM AUTHOR]

The paper presents a method for stability analysis of an elastic system consisting of a ribbed cylindrical shell and noncrossing plates. The influence of the width and thickness of the plate on the buckling stresses and modes is analyzed [ABSTRACT FROM AUTHOR]

The fundamentals of the reduced-stiffness method, which is used in buckling analysis of reinforced and perfect and imperfect nonreinforced shells, are set out. The method is validated analytically and experimentally. The lower bound determined by this method is very close to the experimental lower bound. Some aspects of the current state and prospects for development and generalization of the method are discussed. [ABSTRACT FROM AUTHOR]

The paper presents a technique for stability analysis of cylindrical shells reinforced with longitudinal elements in the form of a plate or a flanged plate. The effect of the widths of the plate and flange on the critical stress and buckling modes is analyzed [ABSTRACT FROM AUTHOR]