A New Rupture Prediction Model for Corroded Pipelines Under Combined Loadings

Abstract

It is commonly believed that bending and other secondary loading will reduce the rupture pressure of a corroded pipe. This paper shows through theory, full-scale tests and finite element analysis (FEA) that this need not be the case in the field where displacement controlled bending and axial loading are induced by differential settlement and axial constraint. Based on this result, a new strain-based rupture prediction model is developed for buried corroded pipes subjected to internal pressure, lateral bending, thermal loading and residual stress. The selection of an appropriate “bulging factor,” the determination of a biaxial strain limit and the treatment of the heat affected zone (HAZ) are also discussed in the paper. The predicted rupture pressures agree well with the full-scale test results.