Fatigue crack growth and coalescence at notches

Abstract An experimental study of the process of fatigue crack growth and coalescence in the region of a notch has been performed. The testing programme consisted of constant amplitude fatigue tests of 24 notched steel bar specimens, 11 of which modelled the crack coalescence process. The results of the experimental programme are examined and compared to exosting design codes that prescribe a method for dealing with adjacent cracks. The crack growth and shape development data presented in the present study indicate that pre-coalescence interaction between adjacent cracks is not an important process and, in fact, that coalescence itself is not instantaneous as the design codes suggest.