High cycle fatigue assessment of steel load-carrying cruciform welded joints: an overview of recent results

Abstract

In this paper, high cycle fatigue failure behavior of steel Loadcarrying Cruciform Welded Joints (LCWJ) is assessed by means of local approaches. Different analytical solutions for weld toe and weld root are extended and applied to illustrate the effects of LCWJ geometry under cycle tension and bending based on Notch Stress Intensity Factors (NSIFs). The extended analytical solutions are validated by comparing finite element data from several simulations in terms of LCWJ models, resulting in a good agreement. A bulk of experimental data taken from tests and the literature is calculated by the proposed solutions as the forms of SED, NSIF and Peak Stress Method (PSM). The results show that the NSIF-based analytical solutions for steel LCWJ are effective for high cycle fatigue failure analyses.

Influence of themo-mechanical treatments and microstructural state on the fatigue behaviour of a weald seam: case of API X60 steel

“…These microstructural effects are associated with welding conditions especially the position of the weld seam according to the orientation of loads and stresses [10][11]. The thermal effect of the welding cycle gives microstructural heterogeneity in this zone (HAZ) made up of several subzones with different microstructures that can cause different behaviours [12][13][14]. A ferrite-bainitic microstructure offers better resistance to crack propagation in the welded zone than the martensitic or bainitic structures [15].…”