Experimental Investigation of Residual Ultimate Strength of Damaged Metallic Pipelines

Abstract

The ultimate strength of metallic pipelines will be inevitably affected when they have suffered from structural damage after mechanical interference. The present experiments aim to investigate the residual ultimate bending strength of metallic pipes with structural damage based on large-scale pipe tests. Artificial damage, such as a dent, metal loss, a crack, and combinations thereof, is introduced to the pipe surface in advance. Four-point bending tests are performed to investigate the structural behavior of metallic pipes in terms of bending moment–curvature diagrams, failure modes, bending capacity, and critical bending curvatures. Test results show that the occurrence of structural damage on the pipe compression side reduces the bending capacity significantly. Only a slight effect has been observed for pipes with damage on the tensile side as long as no fracture failure appears. The possible causes that have introduced experimental errors are presented and discussed. The test data obtained in this paper can be used to further quantify damage effects on bending capacity of seamless pipes with similar D/t ratios. The comparison results in this paper can facilitate the structural integrity design as well as the maintenance of damaged pipes when mechanical interference happens during the service life of pipelines.

Data-driven Methods to Predict the Burst Strength of Corroded Line Pipelines Subjected to Internal Pressure

“…However, pipelines also face big challenges with the exploitation of oil and gas into deep and/or ultra-deep water (Cai et al, 2017;Chin et al, 2020). One of the biggest challenges is the corrosion defect, which may significantly compromise structural integrity and thereby bring severe consequences to the safety of structures and environment (Macdonald and Cosham, 2005;Mohd et al, 2015;Cai et al, 2018bCai et al, , 2019. Therefore, it is necessary to find effective ways to evaluate the integrity of the pipeline so that the risk of pipe leaking or rupture may be reduced.…”

“…Astanin et al (2009) conducted a pipe test to verify an empirical method for the burst pressure of corroded pipelines. Cai et al (2018bCai et al ( , 2019Cai et al ( , 2018a studied the effect of a single corrosion defect on pipe strength based on both experimental tests and numerical simulations.…”