Fatigue Life Estimation of Welded Joint with Different Approaches Using IIW Guidelines and FEA Techniques

The fatigue behavior of welded joints is a very complex task because of its intricate mechanism and the various influence factors which are still under investigation and area of interest for researchers. Fatigue life estimation of welded joints in engineering is mainly based on the type of weld and joint, stress state of the welded joints and the stress concentration at the weld toe and root. There are well established methods such as the Nominal stress approach, the Hot Spot Stress (HSS) approach, and the Effective notch stress approach with pros and cons from application and estimation point of view. This paper focuses on evaluation of welds using Nominal stress approach and effective notch stress approach. Nominal stress approach in case of nonstandard welds and implications created due to typical modelling approaches and boundary conditions in proximity of weld does not give satisfactory results. To counter the challenges faced above we can use the Effective notch stress approach in conjunction with the Nominal stress approach to estimate reliable fatigue safety factor for welds.