Research On Prediction Method Of Residual Strength Of Submarine Pipeline Based On Finite Element Analysis

With the development of China's marine oil and gas resources,the pace of construction of submarine pipelines is also accelerating.Due to the harsh working environment of the submarine oil and gas pipeline,the probability of damage to the pipeline is large.After the pipeline is damaged,the bearing capacity will decrease.If it is not repaired in time,it will cause serious accidents such as oil and gas leakage and oil and gas transmission interruption,which will not only cause huge economic losses,but also cause environmental pollution.However,if the pipeline loss evaluation is too conservative,it will result in insufficient pipeline use and a short waste of maintenance and replacement cycle.Therefore,it is necessary to accurately assess the residual strength of the pipeline after damage,and to provide correct and reliable decision for the maintenance work of the pipeline.This paper studies the residual strength analysis method of submarine pipelines under complex loads.Mainly completed the following work:1.Study the existing pipeline failure evaluation criteria and compare their respective scopes,advantages and disadvantages.2.The finite element method is used to study the relationship between geometric parameters such as length,width and depth of single point defects and the ultimate bearing capacity of damaged pipelines.The parameters such as axial spacing and circumferential spacing of adjacent defects and the ultimate bearing of damaged pipelines are analyzed.The relationship between forces.3.According to the relationship between the geometric parameters of the defect and the residual strength of the pipeline,a parametric model which can be used to quantitatively describe the ultimate bearing capacity of the pipeline is constructed.The accuracy and reliability of the model are verified by experiments.The defect size is used to predict the residual strength of the damaged pipeline on the seabed.4.A calculation model of the ultimate bearing capacity of damaged submarine pipeline under the action of pressure and bending moment load is proposed.After comparison with experimental data,the calculated results of this calculation model have higher accuracy and reliability.