Experimental fatigue crack growth analysis and modelling in part-through circumferentially pre-cracked pipes under pure bending load

In the present work, an attempt has been made to study the fatigue crack growth in a part-through circumferentially notched pipe specimen. It has been observed that under four-point bend cyclic load, the crack propagates in a transverse plane in the radial direction initially followed by propagation in the circumferential direction. The crack extension in the circumferential direction resulted crack growth retardation in the radial direction. This behaviour of the fatigue crack growth has been modelled, and a fatigue life prediction methodology based on an exponential model has been applied for prediction of fatigue crack growth.