sentences:  The point loaded crack solution from the Tada, Paris, and Irwin Stress Intensity Factor Handbook 
  was originally used to determine K (for arbitrary stress fields) by integration over the crack length using the unflawed stress distribution independently for each crack dimension.A new method was developed by F. Grimsley (AFWAL/FIBEC) to determine stress intensity, which used a 2-D Gaussian integration scheme with Richardson Extrapolation which was optimized by G. Sendeckyj (AFWAL/FIBEC).The resulting program was named MODGRO since it was a modified version of ASDGRO.