Theoretical and Numerical Predictions of Burst Pressure of Pipelines

Abstract

It is known that the Tresca yield theory predicts a lower bound of burst pressure, whereas the von Mises yield theory provides an upper bound of burst pressure of pipelines. To accurately predict the burst pressure, the present authors [1] recently developed a new multiaxial yield theory for isotropic hardening materials, based on an average shear stress criterion (ASSC). Extensive classic experiments showed that the ASSC criterion can well correlate the stress-strain relations for both initial yield and subsequent yield states. Based on the ASSC yield theory, a new theoretical solution of the burst pressure of pipelines at plastic collapse is developed as a function of pipe geometry, material hardening exponent, and ultimate tensile strength. This solution is then validated by experimental data for various pipeline steels. The ASSC yield theory is further applied to accurately determine actual burst pressure using available finite element software like ABAQUS, which currently adopts the von Mises yield criterion and the associate flow rule for isotropic elastic-plastic analysis. Four burst failure criteria: the Mises equivalent stress criterion, the maximum principal stress criterion, the Mises equivalent strain criterion and the maximum tensile strain criterion are developed as functions of the ultimate tensile stress and the strain hardening exponent. Application demonstrates that the proposed failure criteria in conjunction with ABAQUS numerical analysis can accurately determine burst pressure of pipelines.