Finite Element Analysis of Limit Pressure for Longitudinal Through-wall Cracked Natural Gas Pipeline

Limit pressure can provide pipeline design parameters and the guarantee of safely operating, thus sav-ing the construction cost and reducing danger of burst accidents. In this paper, three-dimension finite ele-ment is used to study the plastic limit pressures (Pm) of natural gas pipelines under three conditions: with-out defects, having longitudinal and circumferential through-wall cracks each. Based on the results of simu-lation, the corresponding predictive formulations of Pm to the material property, pipe dimension and crack length (or crack angle) are established. Compared with existing predictive models, it comes to these con-cludes as here: if there were no defects in the pipe, Christopher's model (formula 3) can be safely used. But to the conditions that through-wall cracks were included, the already known models would result higher discrepancy, especially for circumferential through wall cracked pipes.