Estimation of stress intensity factors of weld toe surface cracks in tubular K-joints

摘要

A new mesh generation method for uni-planar tubular K-joints containing a semi-elliptical sur-face crack located at the hot-spot region is proposed in this paper. The crack can be of any length and fixed at any position along the brace-chord intersection. In this method, surface crack mesh can be generated automatically. In order to avoid badly distorted elements near the crack front, five different types of elements are used to model the crack front. The significance of the mesh generated using this method is that it is now feasible to obtain the stress intensity factors (SIFs) of this type of tubular joint directly. Comparison of SIFs results obtained by other researcher has been carried out, and convergence tests have been done successfully. Different crack aspect ratio of a/c and crack depth ratio of a/rare used to study the behaviour of such K-joints subjected under balanced axial load and in-plane-bending. The present results prove that the proposed method is both reliable and efficient.