Failure Analysis of Pipeline With Pore Defects

Abstract

During the welding process, the pore defects may be produced in the weld body. Statistic results showed that welding defect is one of the main causes for pipeline failure. According to this factor, this paper presents a detailed description of numerical research to assess the structural condition of circumferential weld seam pipeline with pore defects. Based on elastic-plastic theory, a set of nonlinear finite element analyses of pipelines with pore defects are carried out to study the influence of different sizes and locations on failure mode. Aimed at evaluating the load bearing capacity of pipeline with pore defects, limit stress states are investigated in this paper by using the finite element analysis. By comparing the present analysis results with the relevant standards, a proposed acceptance criterion is brought out. The results presented in this paper can be used to make suggestions on welding procedure qualification and continued safe operation of pipelines.