|
|
||
|
|
|
|
Photograph supplied by Michael Nemeth, NASA Langley Research Center, Hampton, Virginia
This and the next two slides are from "Buckling and postbuckling tests of ring-stiffened circular cylinders loaded by uniform external pressure", NASA TN D-3111, November 1965 by Donaldson A. Dow
SUMMARY:
Experimental results are presented for tests of 10 ring-stiffened cylinders loaded to failure by uniform external air pressure. The proportions of the aluminum-alloy cylinders were such that local buckling (instability between rings) occurred before general instability (instability of the rings and skin as a composite wall). Failure by general instability occurred between about 3/4 atmosphere (76 kN/m^2) for the weakest cylinder to 3 atmospheres (304 kN/m^2) for the strongest.
Test results for local buckling are compared with results from previous tests and with theoretical results. The test cylinders buckled locally at somewhat higher pressures than those of a previous test program but at lower pressures than predicted by classical theory. The result of changes in cylinder geometry on structural efficiency (high-strength, low-mass characteristics) was assessed for the collapse strengths of the cylinders. The study indicates that efficient cylinders have thin skins with many closely spaced low-mass stiffening rings.
Page 42 / 227