Staff engineer, Alcoa Laboratories, Alcoa Center, Pa
Pages: 27 Published: Jan 1979
Fracture toughness, fatigue crack growth rate, and sustained load crack growth data comprise a basic package of materials property information used in predicting growth of cracks by fracture mechanics methods. Accurate analysis requires carefully developed laboratory results using various simple specimen configurations to describe these properties. A contributing factor to variability in life prediction is the lack of consistent procedures for obtaining and reporting this information for use in design. Though a standard does exist for direct fracture toughness determinations (ASTM Method E 399), standards for subcritical crack growth measurement are in various stages of development. Accuracy of life prediction is further confounded by judgment required of the analyst in selecting the most appropriate test and interpreting material property data for use in the computational methodology.
This paper reviews the status on standardization of test practices for characterizing basic material properties used in crack growth analysis. Emphasis is given to aspects of fatigue crack growth because of the relative importance of its characterization to life prediction by damage integration techniques. Other criteria are outlined to provide helpful guidelines to the design engineer seeking to recognize problems and minimize variability in life prediction.
fatigue crack growth, stress corrosion cracking, fracture toughness, crack growth rate, fracture mechanics, test methods, life prediction, fatigue (materials), crack propagation
Paper ID: STP35031S