Early applications of the finite element method to crack problem was
developed by Swedlow and et al. Even though they could get reasonable
accuracy about 5 to 10%, later study showed that solutions in the
vicinity of the crack tip cannot be guranteed to be accurate regardless
of the mesh density around tip. In order to overcome this problem,
people developed special crack tip elements.

In this term paper, I'm going to present 1) Finite Element Method in
Fracture Mechanics and 2) NewFinite Element technique so called Extended Element Method.