Cylindrical shells with discontinuity in the thickness and that are subjected to axisymmetric loading have been analysed. Two types of finite elements are used: the first is based on thin shell theory and the second on thick shell theory. The loadings considered are a uniform internal pressure and a circular ring load at the mid-section. The effect of these loads for various end conditions and various step-ratios in the thickness have been analysed. Numerical results are presented and compared for both the theories. It has been shown that the transverse normal stress acting along the thickness direction is not negligible compared to other stresses at places of discontinuity either in the thickness or in the loading. The weight of the shell is kept constant for various step-ratios. © 1993.

A. Joseph Stanley

Natrajan Ganesan

Cylinders (shapes)

finite element method

stresses

Structural analysis

Structural loads

AXISYMMETRIC LOADING

Cylindrical Shells

discontinuity

THICK SHELL THEORY

THIN SHELL THEORY

Shells (structures)

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Comparison of shell theories in the analysis of cylindrical shells with discontinuity in the thickness

Computers and Structures

Thick shells made of composite materials have been analyzed by using a higher order shell theory. In this theory thickness normal strain and two transverse strains are included. A higher order three-noded isoparametric axisymmetric finite element is used to solve the problem. Numerical experiments with the present element indicate that this element yields accurate vibration results with very few elements. In the present study, the suitability of different theories used for vibration studies has been investigated. Three theories are compared, viz. Love's first approximation shell theory, an improved theory with shear deformation and rotatory inertia, and a shell theory with thickness normal strain and shear deformations. It is found that the shear deformations have an appreciable effect on the vibration characteristics of comparatively thick shells, especially composite shells. A parametric study has been conducted to study the effects of various geometric properties of shell on the free vibration characteristics of conical isotropic and composite shells. The effect of mass distribution on the natural frequencies is also studied in the present work. © 1992.

Journal of Sound and Vibration

Vibration analysis of thick composite clamped conical shells of varying thickness

A conical shell subjected to uniform internal pressure is analysed by the finite element displacement method. The end conditions considered are clamped-clamped (CC), small end clamped-big end free (CF), and small end free-and big end clamped (FC). The semi cone angles considered are (α=) 30, 45 and 60°. It is shown that by properly varying the thickness the deflections and stresses can be brought down considerably. The results are presented in the form of graphs and tables. © 1991.

Engineering Fracture Mechanics

Deformation of varying thickness of conical shells subjected to axisymmetric loading with various end conditions

Journal	Computers and Structures
ISSN	00457949
Open Access	No