This paper based on the finite element method,using ABAQUS software,referring to the groove shape of the actual pipe girth weld and the softening phenomenon of the heat-affected zone material,a nonlinear finite element analysis model of the pipe girth weld with pit defects is established.The stress of pipe girth welds with pit defects under different loads was analyzed. The influence of pit size,weld reinforce-ment and material properties of heat-affected zone on the stress distribution of circumferential welds of pipelines with pit defects was discussed. The results show that obvious stress concentration occurs around the pit,and the depth of the pit has a significant influence on the ultimate bearing capacity of the pipeline. As the depth of the pit increases,the maximum equivalent stress of the corroded pipeline increases significa-ntly,and the maximum stress is concentrated in the weld zone.When the pipeline is under extreme tensile load, the maximum equivalent stress of the pit defect in the weld reinforcement is concentrated in the heat-affected zone;when the depth of the pit is greater than the reinforcement,the maximum equivalent effect force is located at the edge of the pit in the center of the weld.
pipe girth weldpit defectsweld reinforcementfinite element analysissafety assessment