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(a) Basic critical and postcritical equilibrium panths
(b) Elastgic buckling pattern
(c) Pllastic buckling pattern
FROM:
F.M. Mazzolani (1), A. Mandara (2) and G. Di Lauro (2)
(1) Department of Structural Analysis and Design, University Federico II, Naples, Italy
(2) Department of Civil Engineering, Second University of Naples, Aversa, Italy
“Plastic buckling of axially loaded aluminium cylinders: a new design approach”, CIMS 2004, Fourth International Conference on Coupled Instabilities in Metal Structures, Rome, Italy, 27-29 September, 2004
ABSTRACT: The results of a wide F.E.M. analysis on the imperfection sensitivity of axially loaded aluminium cylinders are used to investigate buckling modes occurring in case of relatively thick cylinders (R/t < 200 ÷ 250). The combined effect of geometrical imperfections, inelastic behaviour of material and boundary conditions is considered in order to set-up a refinement of rules given in prEN1993-1-6 dealing with steel shells. The proposal allows for a further exploitation of the cylinder buckling strength in plastic range, which is why it seems rather suited to applications in the field of civil engineering. To this purpose, a special requirement on the initial allowable imperfection level is defined, corresponding to a quality class higher than EC3 class A. Because of its features, the proposal presented herein could be profitably used for the new Part 1-5 “Supplementary rules for shell structures” of Eurocode 9 (prEN1999-1-5), presently under development, which is the very first codification issue at European level dealing with aluminium shell structures.
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