Reference: Singh, R., Carter, B.J., Wawrzynek, P.A., Ingraffea, A.R. (1998)
Universal Crack Closure Integral for SIF
Estimation,Eng. Fract. Mech., Vol 60, No 2, p 133-146.
This is the geometric model with the initial flaw.
The computed stress intensity factors
are plotted below.