Vibration of Varying Thickness Circular Cylinders under Uniform External Pressure

A theoretical and experimental investigation into the general instability of nine swedge-stiffened circularcylinders under uniform external pressure is described. The investigation found that most of the vesselssuffered plastic general instability, and that initial out-of-roundness played a significant role in the magnitude of the elastic knockdown. The theoretical analysis was based on the finite-element method, and a thinness ratio is proposed from which one can determine a plastic reduction factor when more experimental results are available.

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Buckling and post-buckling behavior of thin-walled cylindrical steel shells with varying thickness subjected to uniform external pressure

Thin-Walled Structures ◽

10.1016/j.tws.2006.08.015 ◽

2006 ◽

Vol 44 (8) ◽

pp. 904-909 ◽

Cited By ~ 46

Author(s):

S. Aghajari ◽

K. Abedi ◽

H. Showkati

Keyword(s):

External Pressure ◽

Uniform External Pressure ◽

Varying Thickness ◽

Buckling Behavior ◽

Post Buckling ◽

Thin Walled ◽

Cylindrical Steel

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Inelastic Shell Instability of Geometrically Imperfect Aluminum Alloy Circular Cylinders under Uniform External Pressure

Marine Technology and SNAME News ◽

10.5957/mt1.2008.45.3.175 ◽

2008 ◽

Vol 45 (03) ◽

pp. 175-181

Author(s):

Carl T. F. Ross ◽

Andrew P. F. Little ◽

Graham Brown ◽

Aravinthan Nagappan

Keyword(s):

Aluminum Alloy ◽

Hydrostatic Pressure ◽

Analytical Solution ◽

Structural Design ◽

External Pressure ◽

Circular Cylinders ◽

External Hydrostatic Pressure ◽

Element Analysis ◽

Uniform External Pressure ◽

Design Chart

The paper presents new experimental results on the collapse of unstiffened aluminum alloy circular cylinders suffering elastic and plastic nonsymmetric bifurcation buckling under external hydrostatic pressure. These results complement the results given in two previous Marine Technology papers written by the senior author, which were intended for the structural design of near-perfect unstiffened and ring-stiffened circular conical shells under external hydrostatic pressure. The present paper presents a structural design chart for geometrically imperfect circular cylinders under uniform external pressure, which is more likely to be used than the design charts for the previous near-perfect vessels because it represents the more "usual" case. In addition to an experimental analysis, theoretical analyses were also carried out. An analytical solution by von Mises was used, together with a finite element analysis solution, using the Shell 93 element of the ANSYS computer package. Comparison between ANSYS and the analytical solution was reasonable. A design chart is provided, which looks like it could be quite useful for practical purposes.

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