Computational prediction of fatigue crack paths in ship structural details

Abstract

ABSTRACT The characteristics of fatigue crack propagation and the remaining life assessment of ship structures are investigated focusing attention on a curved crack path due to the effects of welds, complicated stress distributions at three‐dimensional structural joints and structural redundancy. An advanced numerical simulation method is demonstrated for the remaining life assessment for curved crack propagation. The simulation method is based on a step‐by‐step finite‐element analysis. The crack path is predicted by the perturbation method with the local symmetry criterion, which gives a higher order approximation of the crack path, while the finite‐element re‐zoning is carried out by an improved paving method. Fatigue crack paths in the welded structural details of the transverse girder of a ship structure are investigated by experiments and simulation. The present method may offer an efficient simulation‐based tool for the design of critical details, which prevents the failure of the plates forming a compartment boundary.