Abstract
Current studies on fatigue crack initiation in pipelines remain relatively limited. Existing frameworks are confronted with issues including difficulties in crack monitoring and limited consideration of intragranular short-crack propagation. To address these issues, a framework was proposed for predicting fatigue crack initiation life in pipelines with girth welds. The proposed framework incorporates full-scale testing, temperature field simulation and microstructural evolution analysis to overcome limitations in crack measurement and microstructural characterization. In addition, intragranular short-crack propagation has been taken into account in the proposed framework. The proposed framework predicts the fatigue crack initiation life through multiscale coupling. Agreement between the prediction and experimental results supports the validity of the proposed framework. The framework provides reliable predictions of fatigue crack initiation life for pipelines with girth welds under high-cycle fatigue (HCF) conditions.