Fracture mechanics study of a pipe bend with a longitudinal crack under static loading

The regulating norms for nuclear power plant component are based on the assumption that the components have no defects. Therefore it is of major interest to find what values the fracture mechanics parameters assume when a loading which produces in an unflawed elbow stresses which are acceptable according to the regulatory guides is applied to an elbow with cracks. It could be shown that with small flaws ( of arc length, ) calculations assuming linear-elastic behavior give results almost identical as when elastic-plastic behavior is assumed. If the cracks are small and the loading is according to the regulatory guides the initiation value J₁ for stable crack growth is not reached.