STP833: Development of a Fatigue Crack Propagation Model of Incology 901

    Schwartz, BJ
    Pratt & Whitney Aircraft, West Palm Beach, Fla.

    Engsberg, NG
    Pratt & Whitney Aircraft, West Palm Beach, Fla.

    Wilson, DA
    Pratt & Whitney Aircraft, West Palm Beach, Fla.

    Pages: 24    Published: Jan 1984


    Abstract

    An interpolative crack propagation model was developed for Incology 901 using a hyperbolic sine function. The equation log(da/dN) = C1 sinh[C2(logΔK) + C3)] + C4 is used to describe crack growth rates at various operating conditions. Crack propagation rate data for varying stress ratios were examined over a broad range of temperatures and frequencies with this model. Stress ratios (R) investigated included both positive and negative values ranging from −1.0 to a maximum of 0.7. The influence of increasing temperature on crack growth was examined over a temperature range of 260 to 620°C (500 to 1150°F). Frequencies from 0.00833 to 30 Hz were investigated to simulate conditions experienced by a gas turbine engine disk of this material. The resulting model can be used as an effective tool to predict residual life of a gas turbine engine disk, because growth rates can be obtained even where data are unavailable.

    Keywords:

    crack propagation, fracture mechanics, Incology 901, modeling, fatigue, elevated temperature


    Paper ID: STP32557S

    Committee/Subcommittee: E08.06

    DOI: 10.1520/STP32557S


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