Crack growth around stress concentrations in pipes and tubes

Fatigue crack growth behaviour in pipes fundamentally differs from fatigue growth in shafts and flat plates. The aim of this paper is to give a better understanding of this phenomenon. In a first part of the paper, the general principles of the fracture mechanics are concisely described. The energy approach as well as the stress intensity factor (SIF) approach are explained. An analytical method, a numeric method as well as an experimental method to determine the SIF are discussed. Special attention is given to the experimental method. A theoretical model predicting the deflection of a pipe tested in a resonant bending test setup is evaluated and compared to experimental measured deflections. Several methods to measure the crack growth in a pipe during and after a fatigue bending test are discussed. In addition, an overview is given of results obtained by other authors in the field of fatigue crack growth behaviour of pipes.