Static and dynamic analysis on upheaval buckling of unburied subsea pipelines

• Static and dynamic methods are linked together for upheaval buckling of subsea pipelines.
• Loading time is considered in dynamic buckling analysis.
• Upheaval buckling is studied from the standpoint of energy releasing.
• The stress of dynamic analysis is larger than that of static analysis for snap buckling.

Upheaval buckling is one of the most common problems threatening the safe operation of subsea pipelines, which is trigged by the increasing of temperature and inner pressure. In order to predict the critical buckling temperature and post buckling path of upheaval buckling, ABAQUS is used to build four kinds of numerical models, and they are static and dynamic models both in 2D and 3D. Two analysis procedures which combine the static and dynamic processes are applied to aforementioned models. The results show good agreement with existing test data. For snap upheaval buckling, pipelines have two different buckling modes. Such buckling modes are not found in experiments. In addition, only 3D dynamic model can catch such buckling modes. For bifurcation upheaval buckling, predicted buckling temperatures of those models are all acceptable with an error of 5%.