Knockdown factors for cylindrical shells caused by torsional Mode-I type geometric imperfections under axial compression

The buckling problem of circular cylindrical shells under axial compression, external pressure, and torsion is investigated using a displacement function φ. A governing differential equation for the stability of thin cylindrical shells under combined loading of axial compression, external pressure, and torsion is derived. A method for the solutions of this equation is also presented. The advantage in using the present equation over the customary three differential equations for displacements is that only one trial solution is needed in solving the buckling problems as shown in the paper. Four possible combinations of boundary conditions for a simply supported edge are treated. The case of a cylinder under axial compression is carried out in detail. For two types of simple supported boundary conditions, SS1 and SS2, the minimum critical axial buckling stress is found to be 43.5 percent of the well-known classical value Eh/R3(1−ν2) against the 50 percent of the classical value presently known.

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Postbuckling analysis of stiffened laminated cylindrical shells under combined external liquid pressure and axial compression

Engineering Structures ◽

10.1016/s0141-0296(97)00069-2 ◽

1998 ◽

Vol 20 (8) ◽

pp. 738-751 ◽

Cited By ~ 21

Author(s):

Hui-Shen Shen

Keyword(s):

Axial Compression ◽

Cylindrical Shells ◽

Liquid Pressure ◽

Laminated Cylindrical Shells

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Influence of thermomechanical strengthening on the inelastic stability of cylindrical shells under axial compression

Soviet Applied Mechanics ◽

10.1007/bf00883571 ◽

1984 ◽

Vol 20 (1) ◽

pp. 46-50

Author(s):

V. N. Bastun ◽

T. Ya. Gervits ◽

L. M. Shkaraputa

Keyword(s):

Axial Compression ◽

Cylindrical Shells ◽

Inelastic Stability ◽

Thermomechanical Strengthening

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RELIABILITY ASSESSMENT OF AXIALLY COMPRESSED COMPOSITE CYLINDRICAL SHELLS WITH RANDOM IMPERFECTIONS

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455411004063 ◽

2011 ◽

Vol 11 (02) ◽

pp. 215-236 ◽

Cited By ~ 9

Author(s):

MATTEO BROGGI ◽

ADRIANO CALVI ◽

GERHART I. SCHUËLLER

Keyword(s):

Mathematical Models ◽

Axial Compression ◽

Cylindrical Shells ◽

Reliability Assessment ◽

Buckling Analysis ◽

Buckling Load ◽

Experimental Results ◽

Drastic Decrease ◽

Different Types ◽

Probability And Statistics

Cylindrical shells under axial compression are susceptible to buckling and hence require the development of enhanced underlying mathematical models in order to accurately predict the buckling load. Imperfections of the geometry of the cylinders may cause a drastic decrease of the buckling load and give rise to the need of advanced techniques in order to consider these imperfections in a buckling analysis. A deterministic buckling analysis is based on the use of the so-called knockdown factors, which specifies the reduction of the buckling load of the perfect shell in order to account for the inherent uncertainties in the geometry. In this paper, it is shown that these knockdown factors are overly conservative and that the fields of probability and statistics provide a mathematical vehicle for realistically modeling the imperfections. Furthermore, the influence of different types of imperfection on the buckling load are examined and validated with experimental results.

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Buckling analysis of cylindrical shells with random geometric imperfections

International Journal of Non-Linear Mechanics ◽

10.1016/s0020-7462(02)00057-4 ◽

2003 ◽

Vol 38 (7) ◽

pp. 1119-1132 ◽

Cited By ~ 80

Author(s):

C.A. Schenk ◽

G.I. Schuëller

Keyword(s):

Cylindrical Shells ◽

Buckling Analysis ◽

Geometric Imperfections

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Dynamic Buckling of Externally Pressurized Imperfect Cylindrical Shells

Journal of Applied Mechanics ◽

10.1115/1.3423574 ◽

1975 ◽

Vol 42 (2) ◽

pp. 316-320 ◽

Cited By ~ 9

Author(s):

D. Lockhart ◽

J. C. Amazigo

Keyword(s):

Asymptotic Expression ◽

Cylindrical Shells ◽

Simple Relation ◽

Dynamic Buckling ◽

Fourier Component ◽

Buckling Load ◽

Buckling Mode ◽

Geometric Imperfections ◽

Circular Cylindrical Shells ◽

Step Loading

The dynamic buckling of imperfect finite circular cylindrical shells subjected to suddenly applied and subsequently maintained lateral or hydrostatic pressure is studied using a perturbation method. The geometric imperfections are assumed small but arbitrary. A simple asymptotic expression is obtained for the dynamic buckling load in terms of the amplitude of the Fourier component of the imperfection in the shape of the classical buckling mode. Consequently, for small imperfection, there is a simple relation between the dynamic buckling load under step-loading and the static buckling load. This relation is independent of the shape of the imperfection.

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