Finite element analysis on bending failure of offshore floating pipeline

Abstract

Large bending may occur to the offshore floating pipeline under the action of bending load, which further results in the pipeline failure, threatening the transportation safety of crude oil from the offshore oil field. As the failure mechanism of the cord layer and spiral steel wire of pipeline is not clarified, a three-dimensional finite element model of floating pipeline was established with consideration to the torsional behavior of spiral steel wire during pipeline bending, and the validity of the numerical model was verified by bending experiments of example pipelines. The process of bending failure of pipeline was simulated with the finite element model, and the influence of pipeline structure parameters on the minimum bending radius was analyzed. The bending failure of the pipeline is in the mode of spiral steel wire buckling, without strength failure of cord. In addition, the minimum bending radius of pipeline will increase with the increasing of the number of cord layers and the diameter of spiral steel wire or the decreasing of the winding angle of the cord fiber. In general, the results show that the finite element model can effectively simulate the bending behavior of the floating pipelines, which can provide theoretical reference for the structural design and safety application of offshore floating pipelines.

Keywords

• offshore floating pipeline
• minimum bend radius
• finite element analysis
• numerical simulation
• fiber angle
• number of cord layers