Crichlow, W. J.
Department manager, Lockheed-California Co., Burbank, Calif.
Wells, R. H.
Research and development engineer, Lockheed-California Co., Burbank, Calif.
Pages: 46 Published: Jan 1967
Flight safety of the U. S. supersonic transport (SST) requires design data on the rate of crack propagation and the residual static strength of fatigue cracked cylinders. To provide these data an experimental test program was conducted on stiffened cylinders and curved and flat panels of titanium sheet (8A1-1Mo-1V duplex annealed) in the environments representative of SST operations (−110 F, room temperature, and +550 F) and on similar specimens of a candidate steel sheet material (PH-14-8Mo SRH 1050) at room temperatures. Cyclic pressure loading was applied to the cylinders and curved panels. Variation of hoop cross-section area and spacing on longitudinally stiffened cylinders provided design criteria for the crack-arresting properties of hoops in typical fuselage applications. Tension tests of flat panels with and without longitudinal straps provided data on material residual strengths and on the strap attachment qualities in the presence of transverse fatigue cracks. The experimental data were analyzed by means of several analytical formulas so that the design data could be interpreted and presented in compact and usable form.
fatigue (materials), crack propagation, titanium alloys, steels, cylinders, low temperature, high temperature, pressure cycling, structural analysis
Paper ID: STP47227S