Abstract: The four statistical analysis methods for fatigue crack growth rate under constant amplitude loading are given in this paper. The "p-da / dN-ΔK" relationship under given reliability and the c and n values in Paris equation for testing results of LC9 CCT specimen with reliabilities 0.50, 0.90, 0.95 and 0.99 are obtained by using the four methods. Finally, the four methods are compared. It is obviously shown that the lognormal random variable model predicts larger statistical dispersion, and statistically independent Monte Carlo simulation gives much larger statistical dispersion.

Key words: crack growth rate, reliability, statistical analysis