Estimation of Paris-Erdogan law parameters and the influence of environmental factors on crack growth

Following earlier stochastic models of crack growth a simple function of the crack length follows a normal distribution. From this observation the parameters of the Paris-Erdogan model are readily evaluated without the need to estimate the crack growth rate. Moreover, the approach lends itself to the analysis of properly designed experiments to determine the effect of environmental factors on the parameters of the Paris-Erdogan equation through the medium of accelerated failure time models borrowed from reliability theory.