Nonlinear finite element analysis of the limit state and pressure of dented X60 steel pipeline

As a main defect in pipeline, dents have brought great challenge to the integrity of oil and gas pipelines. Numerical study was presented in this paper to investigate the stress and strain state of dented X60 pipe. Suitable failure criteria is adopted and validated by full scale experimental results. And the failure process of dented X60 pipe is elucidated in detail. Based on the established model, effects of dent depth, indenter diameter, initial internal pressure, ratio of diameter to ratio thickness on limit pressure of dented pipe was discussed. Finally, a regression based prediction equation for dented X60 pipe was proposed. Results show this equation predicts accurate results with much less effort and time with regard of 3D finite element models. DOI: http://dx.doi.org/10.5755/j01.mech.23.6.17338