A rogue's gallery of buckled shells.

Most of these photographs are from the presentation given as the "SDM Lecture" at the 1980 AIAA Structures Conference held in Seattle, Washington. The AIAA survey paper based on this "SDM Lecture" is:

"Buckling of Shells – Pitfall for Designers", by David Bushnell,

AIAA Journal, Vol. 19, No. 9, pp. 1183-1226, 1981

INTRODUCTION of the "Pitfalls" paper:

In order to produce efficient, reliable designs and to avoid unexpected catastrophic failure of structures of which thin shells are important components, the engineer must understand the physics of shell buckling.

The objective of this survey is to convey to the reader a “feel” for shell buckling, whether it be due to nonlinear collapse, bifurcation buckling, or a combination of these modes. This intuitive understanding of instability is communicated by a large number of examples involving practical shell structures which may be stiffened, segmented, or branched and which have complex wall constructions.

With such intuitive knowledge the engineer will have an improved ability to foresee situations in which buckling might occur and to modify a design to avoid it. He or she will be able to set up more appropriate models for tests and analytical predictions. The emphasis here is not on the development of equations for the prediction of instability. For such material the reader is referred to the book by Brush and Almroth and other shell buckling literature.

Emphasis is given here to nonlinear behavior caused by a combination of large deflections and plasticity. Also illustrated are stress redistribution effects, stiffener and load-path eccentricity effects, local v. general instability, imperfection sensitivity, and modal interaction in optimized structures. Scattered throughout the text are tips on modeling for computerized analysis.

The survey is divided into nine major sections describing:

1) several examples of catastrophic failure of expensive shell structures;

2) the basics of buckling behavior;

3) “classical” buckling and imperfection sensitivity;

4) nonlinear collapse and the appropriateness of linear bifurcation buckling analyses for general shells;

5) bifurcation buckling with significant nonlinear pre-buckling behavior;

6) effects of boundary conditions, load eccentricity, transverse shear deformation, and stable post-buckling behavior;

7) optimization of buckling-critical structures with consequent modal interaction;

8) a suggested design method for axially compressed cylinders with stiffeners, internal pressure, or other special characteristics; and

9) two examples in which sophisticated buckling analyses are required in order to derive improved designs.

The 1981 paper focuses on static buckling problems.

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