Estimation of stress intensity factor solutions for weld toe cracks in offshore tubular joints

This paper proposes an engineering methodology for estimating stress intensity factor (K) solutions for semi-elliptical weld toe cracks in tubular joints. The methodology uses the T-butt solutions proposed previously by the authors in conjunction with the stress concentration factors and the degrees of bending in the uncracked tubular joints. The estimated K factors are then compared with those obtained from a well-validated finite element procedure and the validity of the proposed methodology is demonstrated. A more refined way of calculating the uncracked stress field parameters which leads to more accurate predictions is also proposed. Fatigue crack growth calculations on experimental joints indicate that the proposed methodology is conservative.