A METHOD TO DETERMINE THE PARAMETER OF THE TSURUI-ISHIKAWA STOCHASTICFATIGUE-CRACK GROWTH SOLUTION

Probabilistic life prediction is needed in structural reliability anal yses of structures because considerable scatter is often observed in f atigue crack growth data. The primary source of this scatter is materi al inhomogeneity which causes the variability of a material's resistan ce against fatigue crack growth. One of the useful ways to analyze sto chastic fatigue crack growth due to random crack growth resistance is the Tsurui-Ishikawa solution which is derived from the generalized Fok ker-Planck equation based on the Markov approximation method. However, no practical methods to determine the parameter of their solution, wh ich determines the distribution of crack growth fatigue life, have bee n reported. Thus, this paper presents a simplified method to determine the parameter of the Tsurui-Ishikawa solution. The proposed method re quires only a few constant DELTAK-controlled fatigue crack growth test s and the procedure is quite simple. In order to confirm the proposed method, Monte-Carlo simulations are also performed and satisfactory re sults are obtained.