FATIGUE CRACK PROPAGATION IN AIRCRAFT MATERIALS
Rept. for 25 Feb 1963-31 Aug 1965
UNITED TECHNOLOGIES CORP STRATFORD CT SIKORSKY AIRCRAFT DIV
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The influence of metallurgical, chemical, and geometric variables on fatigue crack propagation rates was investigated in alloys of aluminum, magnesium, steel, and titanium. Some limited fatigue crack propagation was done in laminated plastics. A possible correlation between fatigue crack propagation, fracture toughness, and tensile strength was also investigated. All materials are ranked according to their resistance to fatigue crack propagation. The critical plane strain fracture toughness, critical plane stress fracture toughness where applicable, ultimate tensile strength, and per cent elongation are also reported for all materials. For the materials tested in this program, there was no appreciable thickness or chemical effect. Shot-peening did increase resistance to fatigue crack propagation. In general, there was an increase in the resistance to fatigue crack propagation in materials with greater ductility. The correlation between fatigue crack propagation and static fracture toughness was very poor. The crack propagation results of laminated plastics was also considered unsatisfactory.
- Laminates and Composite Materials
- Metallurgy and Metallography