Cyclic material properties distribution in laser-welded joints

The paper presents the results of the research on material cyclic properties distribution in a laser-welded joint. The determination of local strains in the weld metal, base metal and the heat-affecting zone was realised with the use of the laser grating extensometer (LES) system in the conditions of completely reversed loadings of a controlled nominal stress value. The conducted research allowed to derive the cyclic stress–strain curves for particular weld zones. The research methodology presented in the paper allows to achieve material data necessary for strain-based and energy-based approaches in the fatigue analysis of complex structural parts made with the laser welding technique. The cyclic properties of joint determined in the research may also be directly applied in numerical analysis of welded joints for material properties modelling.