Thin-walled Shells Of Revolution Research Articles

The ‘panel analysis’ technique in the computational study of axisymmetric thin-walled shell systems

Thin-walled shells of revolution under circumferentially uniform pre-buckling stress states are important fundamental systems, often serving as reference ‘base cases’ to which the behaviour of more complex unsymmetrical systems can be related. However, the same simplicity that often permits closed-form algebraic expressions for the critical buckling load is also often responsible for a lack of localisation and significant ambiguity in the critical buckling mode. The computation of the linear or nonlinear buckling loads requires the systematic trial of many potential buckling modes to identify the one which minimises the necessary strain energy. In times when researchers used custom-written tools usually based on circumferential Fourier series expansions, this operation was relatively straightforward. However, today's analysts using ‘general’ commercial 3D finite element packages must apply careful safeguards to correctly identify the correct buckling load and associated mode in axisymmetric shell systems.This paper presents a detailed computational strategy to accurately and efficiently investigate the correct buckling load and mode number of axisymmetric shell systems using the technique of a ‘panel analysis’. This is implemented in the ABAQUS finite element solver controlled by the SIMULIA™ Isight automation software and the Python object-oriented programming language. The methodology is illustrated on three classical benchmark problems from the scientific literature on the buckling of cylindrical shells under meridional compression, with special attention given to meshing considerations.

Continuum model for a composition of shells of revolution with thermosensitive thickness

An integral variational principle is used to derive the equations of uncoupled thermoelasticity for a composition of thin-walled shells of revolution—a cone, a torus or sphere, and a cylinder smoothly connected along the junction lines. The study is based on a Reissner-typemodel under the assumption that the thickness is sensitive to heating. The generalized position vector of any point on the middle surface is constructed, which permits standardly determining the principal curvatures and components of the basis metric tensor of the middle surface. Equations for temperature functions are derived under the assumption that the temperature field is linear across the thickness of the composition and there are no internal heat sources. The equations of static thermostability and axially symmetric thermoelasticity are written.

Resonant electromechanical vibrations of piezoelectric shells of revolution (review)

Scientific results from studies on the resonant electromechanical vibrations of piezoceramic thin-walled shells of revolution, their fragments, and segmented cylinders are analyzed, systematized, and generalized. Considerable attention is focused on experimental studies of resonant vibrations. It is shown that the modes in which deformation occurs inphase throughout the volume are of the highest intensity in all piezoceramic shell structures

Analysis of creep deformation and creep damage in thin-walled branched shells from materials with different behavior in tension and compression

A constitutive model for describing the creep and creep damage in initially isotropic materials with different properties in tension and compression has been applied to the modeling of creep deformation and creep damage growth in thin-walled shells of revolution with the branched meridian. The approach of establishing the basic equations for axisymmetrically loaded branched shells under creep deformation and creep damage conditions has been introduced. To solve the initial/boundary-value problem, the fourth-order Runge–Kutta–Merson’s method of time integration with the combination of the numerically stable Godunov’s method of discrete orthogonalization is used. The solution of the boundary value problem for the branched shell at each time instant is reduced to integration of the series of systems of ordinary differential equations describing the deformation of each branch and the shell with basic meridian. Some numerical examples are considered, and the processes of creep deformation and creep damage growth in a shell with non-branched meridian as well as in a branched shell are analyzed. The influence of the tension–compression asymmetry on the stress–strain state and damage evolution in a shell with non-branched meridian as well as in a branched shell with time are discussed.

Flexural transient waves in shells of revolution: An asymptotic approach

The transverse asymptotic approximation for flexural waves initiated by edge bending shock loading in thin walled shells of revolution is considered. Methods for solving boundary value problems for this component are constructed with the help of the Laplace transform, the method of expanding the transform in negative powers of the square root from the transform parameter, the saddle point method and other one being utilised. The methods obtained describe solutions for all values of time and tend to the static ones with growth of time.

Elastic buckling and postbuckling behaviour of widely-stiffened conical shells under axial compression

In thin-walled shells of revolution with widely-spaced meridional stiffeners loaded in compression, a local panel buckling may develop. For the particular case of cylindrical panels, the buckling and postbuckling behaviour has been investigated in detail, whereas limited research is available for the more general case of conical panels. In this paper, the linear and non-linear elastic buckling response of the conical panel is studied for a wide range of shell and stiffening parameters by means of an appropriate finite element model. The classical buckling load is determined on the basis of linear analysis. The imperfection sensitivity is studied through non-linear analysis of imperfect conical panels with imperfections affine to the critical mode. Different aspects of the behaviour are quantified through suitably defined curvature parameters.

Numerical analysis of the nonlinear deformation of a spherical pressure vessel made of laminated glass-plastic

The strength and stiffness characteristics of fiber composites are such as to permit their use in many sectors of technology in the manufacture of structural elements having the form of thin-walled shells of revolution of different shapes and structures. The studies [i, 2, 8, i0, ii] examined their stress-strain state, these investigations having solved problems with allowance for variability of the properties of the composites under different loading conditions in different types of structures. Shells of revolution made by the method of continuous winding are widely used as pressure cylinders, tanks, pipelines, and other structures. Most studies of the stress-strain state of such shell elements have been made in a linear formulation. Complicating the service conditions of the structures and increasing the loads while maintaining strict requirements in regard to reliability and weight characteristics make it necessary to use nonlinear models of deformation.

The axial symmetrical edge problems for thin-walled shells of revolution

In this paper, the uniformly valid asymptotic solutions for the axial symmetrical edge problems of thin-walled shells of revolution in bending are given.

Analysis of curved thin-walled shells of revolution.

Boundary value problem solution governed by system of partial differential equations applied to analysis of curved thin walled shells of revolution