STP942: Thermal Mechanical Fatigue of Cast René 80

    Cook, TS
    General Electric Company, AEBG, Cincinnati, OH

    Kim, KS
    General Electric Company, AEBG, Cincinnati, OH

    McKnight, RL
    General Electric Company, AEBG, Cincinnati, OH

    Pages: 16    Published: Jan 1988


    Abstract

    Hot path components of aircraft engines contain complex thermal and mechanical fields which can interact to produce thermal mechanical fatigue (TMF) failure. Development of a model of thermal mechanical fatigue for cast René 80 is underway through TMF experiments, a series of isothermal tests, and finite element analysis. The modelling effort consists of two parts, the determination of a suitable damage parameter and a technique for calculating the quantities required by the damage parameter. Classical plasticity theory was employed in a finite element code to model the TMF deformation. The predicted hysteresis loops were compared to the experimental values; the correlation was excellent for both the in-phase and out-of-phase cycles at 871 to 982°C but not as good as 760 to 871°C. The thermal cycle variation in these tests is limited, but the model's ability to correlate the TMF lives and predict the constitutive behavior of a material whose behavior changes with temperature provides optimism that this analysis may be applied to other TMF situations.

    Keywords:

    nickel-base superalloy, elevated temperature fatigue, thermomechanical fatigue, fatigue life prediction, inelastic finite element analysis, cyclic constitutive behavior


    Paper ID: STP24515S

    Committee/Subcommittee: E08.05

    DOI: 10.1520/STP24515S


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