NUMERICAL PREDICTION OF FATIGUE-CRACK GROWTH OF A SURFACE DEFECT

Fatigue crack growth is modelled by an improved step-by-step finite el ement technique for a shallow and long surface crack in a finite thick ness plate under different combinations of tension and bending loads. The predicted crack shape development is presented for growth through the plate thickness and the shape compared with the widely assumed sem i-elliptical profile. The predictions of the present simulation techni que for the aspect ratio and the number of crack growth cycles are com pared with those obtained both by Newman and Raju's method, and experi mental results for aspect ratio changes taken from the literature.