Fatigue life estimation for ITER CS conductor jacket by probabilistic fracture mechanics

The conductor jacket of the ITER central solenoid (CS) will experience a cyclic tension load due to the electromagnetic forces during operation. The jacket is designed to sustain at least 60,000 full stress cycles. Probabilistic fracture mechanics (PFM) has been applied to estimate the fatigue life of the jacket. The PFM analysis covers almost all independent variables and the correlation among them. It includes Monte Carlo simulation, small sample statistics, and uncertainty analysis. As the basis of PFM, the defects in welds are first discussed, a 3D defect model is developed, deterministic fracture mechanics is reviewed, and a method to estimate the fatigue initiation life is proposed. The results of PFM analysis on the CS conductor jacket made of the alloy JK2LB show that the relationship between the reliability in the high end and the total fatigue life follows a Weibull distribution.