ABSTRACT
This paper presents two different approaches in estimating the effective notch stress, namely the extrapolation method and the method based on the geometric scaling of the existing hot-spot stress solution, for welded circular hollow section X-joints subjected to three different brace loadings. The extrapolation method aligns with the extrapolation approach to determine the hot-sot stress approach in the design recommendations, and eliminates the requirement to model a 1 mm notch radius as prescribed in the fatigue design code. The method based on the existing hot-spot stress solution further reduces the mesh requirement in computing the notch stresses, by using a mesh required for convergent hot-spot stresses, or based on existing parametric equations for the structural hot-spot stresses. The comparison of the effective notch stress assessment against existing fatigue test results collated from the literature re-affirms the close agreement of both methods in assessing the fatigue lives of welded tubular joints.
