Study On Burst Capacity Of Corroded Pipeline With Single Defect

With the development of oil and gas industry, the pipelines are playing a more and more important role in China. As the arteries of the domestic economy, pipelines provide us not only convenience and opportunity but also safety problems. Pipeline corrosion would become more and more severely with the increasing of operation time, The corrosion defects would cause wall thickness thinning, ultimate bearing capacity droping, and even result in the local corrosion body perforating or rupture accidents. In order to predict the influence of corrosion defects on pipeline integrity, it is of necesity to evaluate the burst capacity of the corroded pipeline.The current domestic scholars focus on studing on the influence of pipe and corrosion defect geometries on the ultimate capacity of corroded pipelines by numerical analysis. Combined with experimental and numerical results, the effects of steel strength, corrosion shape, corrosion length and corrosion depth on burst capacity of corroded pipes are studied.Assessment methods of corroded pipelines under the internal pressure widely used abroad was summaried to study the effect of factors on burst capacity.The experimental results of corroded pipelines under internal pressure published in the papers were collected and categorized. The assessment methods were employed to predict the burst capacity of experimental cases. Based on the comparision of prediction and experimental results, accuracy and applicability of assessment methods are discussed. Considering the factors such as steel strength, corrosion shape, corrosion geometry, and using the experimental results, an updated capacity equation of corroded pipeline with single defects was proposed.Residual strength of corroded pipelines under internal pressure was calculated by the finite element method software ANSYS. The effects of steel strength, corrosion shape, corrosion length and corrosion depth on burst capacity are analyzed. Based on the FE results, a capacity equation to predict burst strength of corroded pipelines under internal pressure is submitted by fitting method.