Data for Fail-Safe Design of the Supersonic Transport Pressure Cabin

The concept of fail-safe structure has introduced requirements for evaluation of new types of material properties and new sets of conditions for the design of pressure cabins of high altitude aircraft. A brief review is given of the fracture toughness properties of candidate materials for the SST environment. The results of recent tests on residual strength and rate of crack growth in stiffened and unstiffened panels and cylinders made from titanium and steel are presented. The results of a titanium full-scale fuselage panel tested under heat (550–650 F) and cyclic pressure are discussed in light of SST design requirements.