Creep crack growth life estimation of a surface crack in pressure vessels

Using the newly developed method, a procedure for assessing creep crack growth life was demonstrated for an elliptic axial surface crack located on the internal surface of a pressurized vessel at high temperature. C-t values at both the deepest point along the crack front and also at the crack tip on the surface were estimated. Then, the aspect ratios of the surface crack were updated for every time step of crack growth calculations and were reflected in determining C-t value of the next step. Changes of crack depth, crack size and C-t values at the deepest point and surface point of the crack tip are estimated and used to predict the residual life and the evolution of crack shape during creep crack growth.