Welded joints in steel structures are subjected to high strain amplitude during earthquake, which could cause a low cycle fatigue crack. To assess low cycle fatigue strength of welded joints, an estimation method based on local strain range at a crack initiation point has been established. In this method, an FE model with extremely-fine mesh is needed to obtain the local strain range accurately. In this paper, a prediction method of the local strain range from a model with relatively coarse mesh was proposed. Strain ranges obtained from coarse-mesh models were related to the local strain ranges from fine-mesh models. A prediction formula of the local strain range which is applicable to T-shaped joints, cruciform joints and out-of-plane gusset joints was established.
