Material Nonlinearity Effects in Optimization Considerations of Stiffened Cylinders and Interpretation of Test Data Scatter for Compressive Buckling
Final technical rept.
STANFORD UNIV CA DEPT OF AERONAUTICS AND ASTRONAUTICS
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A limited optimization study is undertaken of imperfect, eccentrically stiffened 2024-T3 aluminum alloy cylinders under axial compression based on 1 a linear theory with applied buckling load reduction factors to account for initial imperfections and inelasticity and 2 a kinematically and constitutively nonlinear maximum strength analysis. The latter is shown to be less conservative for the most efficient design combined stringer- and ring- stiffening. Credibility of the maximum strength approach is domonstrated through its use in correlating experimental results obtained for 10- and 14-in. diameter steel cylinders having different proportional-limit stresses, respectively. Finally, material nonlinearity is shown to offer a plausible qualitative explanation for a significant amount of the scatter in axial compression tests for cylinders with radius-to-thickness ratios of practical interest.