Local strain approaches for LCF life prediction of ship welded joints

The aim of this research activity is to predict the low-cycle fatigue life of welded joints used for ship structures, applying two methods: the effective notch strain approach and the structural strain approach. The first method was applied performing elastic-plastic finite element analyses (FEA), using different cyclic stress-strain curves for base material, heat affected zone and weld metal, while the second method is mesh insensitive for applications in high cycle fatigue regime and has recently been adapted for applications in low cycle fatigue regime. The geometry used for the first method was acquired by means of a 3D scanner. Effective notch strain results and structural strain results were used to predict the low cycle fatigue life.