Energy release rates are obtained using ABAQUS program for semi-elliptical surface flaws existing in the longitudinal direction of reactor pressure vessel under internal pressure and transient thermal loadings. A 3-dimensional FEM analysis is carried out to obtain the transient temperature field and the energy release rates as a function of time and position along the crack front.
The results are summarized as follows:
1. The energy release rates computed from thermo-elasticity is larger than from thermo-elastoplasticity.
2. The energy release rate attains the maximum at the surface for the cases of aspect ratio, a/c=1.0, 0.8 and 0.6 while it is maximum at the inner point for the case of a/c=0.2.
