Fatigue crack growth and penetration behaviour in a pipe subjected to bending load

A fatigue test has been carried out at room temperature in air on a carbon steel pipe which has a crack on its outer surface. Special attention was paid to crack growth rate, crack shape, fatigue life and crack opening displacement. A new equation was proposed for evaluating K after crack penetration. The main results obtained in this study were as follows: (1) before crack penetration, crack growth behaviour such as aspect ratio and leak life were evaluated using Newman-Raju's equation and proposed plate model; (2) after crack penetration, crack growth behaviour such as crack shape, fatigue life and crack opening displacement were evaluated using the equation and pipe model proposed in this paper.