Abstract: The finite element analysis model of a welded tubular K-joint is built firstly. The stress distribution along the weld toe for tubular K-joints is calculated. Thereafter, the effect of some main geometrical parameters on the stress distribution along the weld for tubular K-joints under balanced axial loads is investigated through the parametric study on 420 K-joint mod-els. Through the numerical analysis on these models, it is found that the stress distribution along the weld toe for tubular K-joints under balanced axial loads is determined by some geometrical parameters. The position of the hot spot stress shifts between the crown and the saddle when some geometrical parameters are different. As the location of the hot spot stress is the position of the surface crack initiation, the process of the fatigue and fracture failure of a tubular K-joint is thus influ-enced by the geometrical parameters of this K-joint.

Key words: Balanced axial loads, Geometrical parameters, Hot spot stress, Tubular K-joints, Weld seam