A generalized weighted yield criterion: Theoretical derivation and its application in the plastic failure analysis of pipeline with corroded defects

Abstract

For the aim of predicting the failure pressure of pipelines accurately, a new yield criterion that embeds two physical parameters, i.e. the tension-compression ratio and the shear-tension ratio, is proposed by weighting the squares of the shear stresses. The yield criterion is proved to be universal and can convert into different yield criteria suitable for different materials. The experimental results show that the criterion can coincide well with the experimental data and can describe the yield characteristics of different materials very well. Base on the above research result, the mechanical analysis of a pipeline is executed based on the limit analysis method, and the analytical formulas of the burst pressures without and with defects are obtained by considering the strain-hardening behavior. The validation shows that both the theoretical values of burst pressures of pipelines with and without corroded defect based on the present yield criterion agree well with the experimental values. The sensitivity analysis is also carried out, which shows that the burst pressure of the uncorroded pipe decreases when the strain hardening exponent increases, while increases when the thickness-diameter ratio increases. In addition, the burst pressure of the corroded pipeline decreases when the defect depth or its length increases.