PROCEDURES FOR FRACTURE TOUGHNESS CHARACTERIZATION AND INTERPRETATIONS TO FAILURE-SAFE DESIGN FOR STRUCTURAL TITANIUM ALLOYS (To Purchase Call 1-800-854-7179 USA/Canada or 303-397-7956 Worldwide)
Considerable interest exists in the use of thick section titanium alloys for structural applications requiring materials of high strength-to-density ratios. An important factor in the failure-safe design of such structures is the fracture toughness characteristics of the material. Until recently fracture toughness information for intermediate and high strength titanium alloys was available only for material of sheet thickness. This report presents a summary o??he fracture toughness characteristics of titanium alloys produced as plate of relatively large dimensions. It also presents procedures for the interpretation of fracture toughness tests in terms of critical flaw size and stress level factors for sections of 1- to 3-in. thickness. The procedures are based on correlations of Charpy-V notch (C ) and Dynamic Tear (DT) tests to fracture mechanics tests in the range where valid plane strain stress intensity values (KIc) can be established. Extrapolations of the correlations are used to cover conditions of higher fracture toughness. The correlation and interpretative procedures are the same as have been described previously for steels. Flaw sizestress calculations based on the fracture mechanics parameters KIc@ and Kc@ provide for the desired quantitative interpretations of the C@ and DT tests. The procedural simplicity of the engineering tests is thereby coupled with the analytical capabilities of fracture mechanics theory.