Effect of Diameter to Thickness Ratio and External Pressure on the Velocity of Dynamic Buckle Propagation in Offshore Pipelines

摘要

In this paper, a numerical study of the dynamic propagation ofbuckles initiated in long pipes under external pressure is presented.The model accounts for the inertia of the pipe, the nonlinearityintroduced by contact between the collapsing walls of the pipe whilethe material is modeled as a finitely deforming elastic plastic solid.The buckling and collapse are assumed to take place in vacuum.The numerical results, obtained from nonlinear finite element analysisare compared with the results of the experimental study on small-scalemodels, undertaken by Kyriakides & Netto (2000). Comparisonshows that the finite element results have very close agreement withthe experimental behavior.The effect of external pressure on the velocity of dynamic bucklepropagation for different diameter to thickness ratios is separatelyinvestigated and their proper relations are derived.