A series of creep buckling tests have been run on flat compression panels N of integral skin-stringer type construction using 2024-T4. and 7075-76 materials. The buckling specimens were the compression surfaces of constant depth and constant length beams, and were designed to be in the short column range. The tests were conducted at a constant bending moment, constant temperature, and uninterrupted time until failure. Each of the two materials was tested at four elevated temperatures with stress levels selected to effect creep failures over a range of time from fractional hours to an upper limit of 200 hours.nThe results are shown compared to a temperature-time parameter previously proposed for tensile creep rupture, via., TR(l7+log t), to indicate the similarities in stress-temperature-lifetime relationships for the different basic mechanisms of failure. Utilization of the isochronous tangent modulus in the straight line column equation results In a generally good comparison of analysis and experiment for the 2024-T4 specimens. The Isochronous tangent modulus method proved less reliable for 7075-T6, but these specimens are subject to further comparison when more tension creep deformation becomes available. Design curves for the structural configuration used in this investigation are presented in the form of constant-time failure curves.
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