Experiments on the postbuckling behavior of circular cylindrical shells under compression

1975 ◽  
Vol 15 (1) ◽  
pp. 23-28 ◽  
Author(s):  
N. Yamaki ◽  
K. Otomo ◽  
K. Matsuda
Author(s):  
Takaya Kobayashi ◽  
Yasuko Mihara

In designing a modern lightweight structure, it is of technical importance to assure its safety against buckling under the applied loading conditions. For this issue, the determination of the critical load in an ideal condition is not sufficient, but it is further required to clarify the postbuckling behavior, that is, the behavior of the structure after passing through the critical load. One of the reasons is to estimate the effect of practically unavoidable imperfections on the critical load, and the second reason is to evaluate the ultimate strength to exploit the load-carrying capacity of the structure. For the buckling problem of circular cylindrical shells under axial compression, a number of experimental and theoretical studies have been made by many researchers. In the case of the very thin shell that exhibits elastic buckling, experimental results show that after the primary buckling, secondary buckling takes place accompanying successive reductions in the number of circumferential waves at every mode shift on systematic (one-by-one) basis. In this paper, we traced this successive buckling of circular cylindrical shells using the latest in general-purpose FEM technology. We carried out our studies with three approaches: the arc-length method (the modified Riks method); the static stabilizing method with the aid of (artificial) damping especially, for the local instability; and the explicit dynamic procedure. The studies accomplished the simulation of successive buckling following unstable paths, and showed agreement with the experimental results.


Author(s):  
JOSEPH KEMPNER ◽  
K. A. V. PANDALAI ◽  
SHARAD A. PATEL ◽  
JACQUES CROUZET-PASCAL

1977 ◽  
Vol 44 (3) ◽  
pp. 475-481 ◽  
Author(s):  
A. Maewal ◽  
W. Nachbar

Postbuckling behavior of clamped circular cylindrical shells of finite length under uniform axial compression is analyzed using a potential-energy-based, displacement finite-element method. Contour maps of equal radial deflection computed from this analysis for one-tier and two-tier postbuckled, stable equilibrium patterns show very good agreement with experimentally measured contour maps for a polyester shell with L/R = 0.7 and R/h = 405. Developed for these computations, and essential for them, are: (a) A 48 DOF shell element; (b) A method to calculate accurately for the perfect shell the nonlinear fundamental path and its bifurcation points. The lowest such bifurcation point does not correspond to the first observed postbuckle pattern, which is reproduced by calculating the continuous equilibrium path from the sixth bifurcation point. Patterns of successive postbuckling shapes that are formed under additional end-shortening are determined by using a special technique to calculate equilibrium paths extending continuously from still higher bifurcation points on the fundamental path.


Sign in / Sign up

Export Citation Format

Share Document