疲劳裂纹扩展速率统计分析

STATISTICAL ANALYSIS OF FATIGUE CRACK GROWTH DATA

给出了4种常幅载荷下疲劳裂纹扩展速率的统计处理方法,获得了在规定存活率P下的“P-da/dN-△K”关系,并对LC9中心裂纹试样试验数据进行了统计分析,给出了存活率为0.50、0.90、0.95和0.99时Paris方程中的c和n值。最后对4种方法进行了比较。

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.