CrackGrowth

There are three regions on crack growth curve

I. Threshold region

II. Paris region

III. Stable tearing crack growth region (Forman)

Paris relation (linear equation in double log plot):

\[\frac{da}{dN}=C \Delta K^m\]

Forman relation:

\[\frac{da}{dN}=\frac{C \Delta K^m}{[1-R][K_c-K_{max}]}\]