Fatigue strength assessment of welded joints in the marine environment

Welding is a commonly applied joining method in many applications arctic and marine conditions, e.g., ship offshore structures, energy production equipment. Such are usually subjected to fluctuating load during decades-long service, they may experience millions of cycles. Consequently, fatigue strength design acceptable flaw sizes the welded details these structures among most important criteria. Multiple assessment approaches exist for assessing detail. The present study introduces numerical analytical assessment, conducted on non-load-carrying X-joint, which representative joint type used steel constructions. Fatigue analyses carried out following DNVGL-RP-C203 BS7910:2013 guidelines structures. stress intensity factors (SIFs) linear elastic fracture mechanics (LEFM) were obtained using three different methods: weight function approach, equations provided IIW Recommendations, by conducting crack propagation analysis Franc2D software. All methods had good agreement particularly short depths, indicating applicability analyses. results showed that consideration degree bending at detail crucial due distinguishing notch membrane loading, distributions through-thickness direction. In addition, it was found LEFM-based life assessments significantly more conservative than predictions structural hot-spot effective approaches.