Low-cycle fatigue crack initiation life of hull-notched plate considering short crack effect and accumulative plastic damage: Fid-Bau Portal

Low-cycle fatigue crack initiation life of hull-notched plate considering short crack effect and accumulative plastic damage

Deng, J.L. / Yang, P. / Chen, Y.

Abstract

Highlights•The initiation and propagation of short cracks reduces the fatigue stress concentration factor of notch root.•Accumulative plastic deformation at notch root was significantly reduces the tangential stiffness of notched plates.•The accumulative plastic deformation at the notch root will gradually increase and eventually lead to the depletion of the ductility of the notched plates that eventually causes failure damage.

AbstractWhen studying the low-cycle fatigue crack initiation life of notched plates, the effects of fatigue short crack and accumulative plastic damage in the vicinity of the notch should be considered. The low-cycle fatigue crack initiation life of notched plates has been revised in the analysis process by considering the short crack initiation and expansion of notch stress concentration area. By determining the accumulative plastic deformation in the vicinity of a notch under low-cycle fatigue loads, a predictive model of low-cycle fatigue crack initiation life was presented for notched plates, and the relative influence factors were quantitatively analyzed. A comparison study verified that the results obtained from the presented calculation model correlate quite well with those from the existing experiments. Some important conclusions were drawn from the study on considering the effects of short crack and accumulative plastic damage. The presented method may be used for predicting the low-cycle fatigue crack initiation life of ship plate.