Lateral global buckling high-order mode analysis of a submarine pipeline with imperfection

With the increasing development and utilization of offshore oil and gas resources, global buckling failures of pipelines subjected to high temperatures are becoming increasingly important. Due to human factors or the condition of an uneven seabed, local bends are produced in the process of pipeline manufacturing and laying. That bend which called geometric initial imperfection could trigger the global buckling of a submarine pipeline. The analytical solutions of high-order lateral buckling for a pipeline with a single arch symmetric and a two-arch anti-symmetric initial imperfection are derived in this paper. The analytical results of the high-order modes are then compared with those of the low-order modes. The modified Riks method is applied to simulate global buckling of the pipeline with imperfection under high temperature and high pressure. The numerical simulation results are compared with the analytical ones, and the effects of initial imperfection, the restraint of the foundation soil to the pipeline, the geometry of the pipeline on global buckling are analyzed.