A dynamic fracture model of the pipeline with girth weld considering welding residual stresses
Qiankun Zhao, Yuguang Cao, Zhenghao Jiao, Ying Zhen, Yizhen Zu
Abstract
Abstract The fracture analysis of girth‐welded pipes is a vital link in the integrity assessment of oil and gas pipelines. However, the effect of welding residual stresses (WRS) on the load‐carrying capacity of the girth‐welded pipe with the crack remains unclear. In this study, based on the WRS simulation results verified by the full‐scale pipe welding experiment, a dynamic fracture finite element model could describe the fracture process of the pipe with the crack in the inner surface of the girth weld considering WRS was developed by the Gurson–Tvergaard–Needleman (GTN) damage model. Based on this fracture model, the fracture behavior of the pipe under tensile load in the presence of WRS was clarified, and the effect of WRS on the load‐carrying capacity was studied. The results indicated that the critical displacement and strain capacity of the pipeline decreased by 12.42% and 13.04% due to the negative action of the WRS.