Short Cylindrical Shells Research Articles

Investigation of resonance vibrations of a short viscoelastic cylindrical shell

Investigation of resonance vibrations of a short viscoelastic cylindrical shell

Dynamic Deformations and Stresses in a Cantilever Cylindrical Shell under Impulsive Loads

In this paper, the dynamic displacements and stresses of a cantilever circular cylindrical shell, which is suddenly loaded by shearing forces on its free edge, are analyzed within the framework of Flugge's shell theory. As a result, it is shown that the radial displacement and the membrane force variations in time are much affected mainly by the lowest mode, and the bending moment variations are also affected by the higher mode, and in the case of a short cylindrical shell the dynamic factor, defined by the ratio of the dynamic maximum value to the static one, for the radial displacement at the free edge is smaller than 2 and that for the bending moment at the fixed edge is larger than 2, and as the cylindrical shell becomes long, that for each case tends to 2.

The elasto-plastic deformation of a supported short cylindrical shell of mild steel under internal pressure

The elasto-plastic deformation of a thin-walled cylindrical shell under internal pressure was analysed using deformation theory together with Mises' yield criterion. A derived system of nonlinear differential equations was solved numerically by computer using the Runge-Kutta-Gill method. A corresponding experiment was performed and the theoretical result coincided with the experimental one very well.

Buckling of Short Cylindrical Shells under Axial Compression

Approximate closed form solutions for the buckling of short circular cylindrical shells under uniform and nonuniform axial compression are obtained. The analysis is based on Donnell's equations using a Galerkin procedure to obtain bounds on the true eigenvalues. The boundary conditions considered are the four possibilities of simple support. Good agreement is shown with previous numerical results. The Koiter mode of instability is reconsidered through the examination of a simple model. The question as to its practical significance is raised.

Elasto-Plastic Deformation of a Supported Short Cylindrical Shell of Mild Steel under Internal Pressure : 1st Report, Theoretical Analysis on Supported Cylinder

Elasto-Plastic Deformation of a Supported Short Cylindrical Shell of Mild Steel under Internal Pressure : 1st Report, Theoretical Analysis on Supported Cylinder

Elasto-Plastic Deformation of a Supported Short Cylindrical Shell of Mild Steel under Internal Pressure : 2nd Report, Experimental Analysis

Elasto-Plastic Deformation of a Supported Short Cylindrical Shell of Mild Steel under Internal Pressure : 2nd Report, Experimental Analysis

The mechanics of a certain class of pumps

A so-called elastodynamic pump has been developed for the purpose of studying flow in a recirculatory system which is intended to simulate certain mechanical aspects of the flow in a human cardiovascular system. It consists essentially of two rubber hemispheroids attached one to each end of a short cylindrical shell to form a compact fluid container. A check valve is provided at an inlet port to the cylindrical shell and another check valve at the outlet port. A periodic driving force is applied to the rubber hemispheroids by a cam activated device. The cam is shaped to produce the desired driving force function. It is fitted to a shaft which rotates at a fixed predetermined speed, using a time-controlled motor. The periodic force applied to the pump produces a unicursal flow in any fluid system into which the pump is inserted. The performance characteristics of the pump have been determined with certain flow calibration apparatus. As a consequence, characteristics of the pump, which show flow delivery as a function of pressure developed, have been determined. Curves of these data are presented for several operating conditions. The use of the pump for studies of flow in the human cardiovascular system is discussed.

Koiter's Buckling Mode for Short Cylindrical Shells

All working equations (except the assumed deflections) are derived from operations performed on the energy functional, that is, the summation of all the quadratic energy terms associated with the deformation during buckling, as developed by Koiter. This is given in Ref. 1 and has been modified in Ref. 2 to a more suitable form by the addition and subtraction of terms which are shown to be of negligible magnitude. The equilibrium equations in the x, y, and z directions are achieved by applying variational operations to the modified energy functional (including appropriate load terms) with respect to u, v, and w, the shell displacements and their derivatives in the longitudinal and circumferential directions in turn, and setting equal to zero. Two of the four boundary conditions are those traditionally associated with simple supports, namely, that the radial deflections and the axial bending moments at the ends of the cylinder are zero. For the other two conditions it is assumed that the circumferential shear stress ixy and the change in axial stress ax are both zero at the ends. The last three conditions are so-called natural boundary conditions derivable from the modified energy functional. Assumed deflections are operated upon according to the equilibrium equations and these, in turn, are reduced to a single characteristic equation in terms of the unknown constant coefficients of the radial deflection w. The roots of this equation, which are functions of the shell parameters, the loading, and the wave numbers in the axial and circumferential directions, are then determined. The assumed deflections are used in the boundary

Experimental Investigation of a Supported Short Cylindrical Shell of Aluminium Alloy under Internal Pressure

Experimental Investigation of a Supported Short Cylindrical Shell of Aluminium Alloy under Internal Pressure

Deformation of a supported short cylindrical shell of aluminum alloy under internal pressure

In order to analyze the deformation due to internal pressure of thin cylindrical shells of materials having nonlinear stress-strain relations, fundamental equations were derived by using Kirchhoff's hypothesis and introducing a parameter showing the effect of compressibility of the material. The equations were applied to a supported short cylindrical shell of aluminum alloy under internal pressure. In order to investigate the validity of the assumptions, the analytical results were compared with experimental results.The analytical results of the axial strain components on the outer and inner surfaces are remarkably different from each other. The complicated variation of the distribution of axial strain on the inner surface with increase of pressure is attributed to the nonlinearity of the deformation, and such a trend was verified clearly by the corresponding experiment.

Dynamic plastic flow buckling of short cylindrical shells due to impulsive loading

A theory is postulated to explain the dynamic plastic buckling of short cylindrical shells subjected to uniform radially inward impulses. Formulas are derived which predict wavelengths (or mode numbers) and threshold impulses in general agreement with the experimental results that are presented. According to the theory, the restoring moment primarily consists of a directional moment brought about by yielding in a biaxial plastic state of stress; for the practical strain hardening values used the hardening contribution to the restoring moment is secondary. This conclusion is based on the relative influences on the preferred modes and threshold impulses.

Analysis of short cylindrical shells of variable wall thickness.

Analysis of short cylindrical shells of variable wall thickness.

Shear and Bending of the Walls of Short Cylindrical Shells

Equations are developed for axisymmetric distortion of cylindrical shells including the effect of shear in the walls. Numerical results are presented for determining bending moment and shear in short cylindrical shells from the slopes and radial displacements of the walls at the two ends. The range of dimensions for which numerical results are given go up to thickness/length ratios of 0.5. It is found that including the effect of shear in the walls reduces the bending moment for given displacements to less than half in some cases.

Discussion: “Shear and Bending of the Walls of Short Cylindrical Shells” (Levy, S., 1965, ASME J. Eng. Ind., 87, pp. 309–313)

Discussion: “Shear and Bending of the Walls of Short Cylindrical Shells” (Levy, S., 1965, ASME J. Eng. Ind., 87, pp. 309–313)

Closure to “Discussion of ‘Shear and Bending of the Walls of Short Cylindrical Shells’” (1965, ASME J. Eng. Ind., 87, p. 314)

Closure to “Discussion of ‘Shear and Bending of the Walls of Short Cylindrical Shells’” (1965, ASME J. Eng. Ind., 87, p. 314)

A useful solution for short cylindrical shells and other applications

The general solution to the basic differential equation d 4w dy 4 +4w = −4f(y) is transformed from the primary form treated in most texts to an alternate form in which each integration constant corresponds to one edge condition at y = 0. The relationships between the integration constants of the two forms are derived and the values for the transformed functions are tabulated. The particular solution is derived in general and given in unique form for various functional forms of f( y). Matrix notation is used throughout the derivations; however, a knowledge of matrix theory is not needed for application of the results.

2049 極めて短い円筒曲板の近似式(構造)

2049 極めて短い円筒曲板の近似式(構造)