STP520: Predicting Service Life in a Fatigue-Creep Environment

    Ellison, EG
    Reader, University of Bristol,

    Smith, EM
    Senior lecturer, University of Newcastle-Upon-Tyne,

    Pages: 38    Published: Jan 1973


    Abstract

    Two current approaches to prediction of life to crack initiation are reviewed, the first based on modification of fatigue types of analyses, the second on use of cumulative fatigue and creep damage models. Methods of allowing for stress and strain concentrations are examined, and attention directed to the possibility of environment significantly affecting results. The fracture mechanics approach to estimating rates of crack propagation is discussed.

    For computer analyses of highly critical sections of components, formulation of constitutive equations on a continuum-metallurgical basis is considered, some possible directions for future work are indicated. An example of prediction of failure through growth of voids in creep is given.

    Finally, present design practice is outlined, and the importance of accurate knowledge of service conditions emphasized.

    Keywords:

    fatigue (materials), thermal fatigue, creep properties, crack initiation, crack propagation, failure, predictions, accelerated tests, damage, stress analysis, constitutive equations, deformation, cavitation corrosion, intergranular corrosion, transgranular corrosion


    Paper ID: STP38872S

    Committee/Subcommittee: E08.05

    DOI: 10.1520/STP38872S


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