Method of Assessment of the Residual Life of Pipes of the Linear Part of the Pipeline with the Typical Defects according to the Crack Resistance Criteria under Cyclic Loading

Abstract

A method of estimating of the residual life of pipes for linear part of the pipeline with the typical defects under cyclic loading based on the deformation approach based on measuring the density of the specimen and plotting the cyclic elastic-plastic fracture diagram for the specimen with a crack is described in the paper. The correction for plasticity material, taking into account the actual cross-sectional dimensions of the specimen in the plane of crack growth, is applied for the determination of stress intensity factors. The algorithm of calculation and experimental prediction of the residual life of pipes for linear part of the pipeline with a typical dangerous defects (longitudinal crack, a crack in the dent, corrosion pitting with crack) on the criterion of crack growth resistance under cyclic loading after long time operation with account of influence of corrosion-erosion processes and deformation aging of pipe material is proposed.

Keywords

• crack resistance
• survivability
• oil pipeline
• long-term operation
• stress intensity factor
• density
• residual life