Finite element analysis and fatigue design of a welded construction machinery component using different concepts

In this paper a finite element model is developed and verified for weld fatigue evaluation. The investigated component is a welded A-stay beam structure in an Articulated Hauler. The investigation includes load data acquisition, strain measurements and full-scale fatigue test under spectrum loading. The FE model considers the non-linear geometrical effects and boundary conditions by including the adjacent screw connection and in some surfaces meshed with contact elements. The fatigue failures observed were in the weld root. An investigation of weld quality showed relatively large lack of penetration in the weld root. Different fatigue design concepts; nominal stress, structural hot spot stress, effective notch stress and linear elastic fracture mechanics are compared regarding work effort and analysis and life prediction accuracy. The comparison between the different fatigue design codes and concepts shows a large scatter in estimated fatigue life for the welded component.