Based on the Hamilton principle,dynamic differential equation of the submarine pipeline span,under the interaction of internal flow and external environmental loads,is established. A constraint-equivalent method is us...Based on the Hamilton principle,dynamic differential equation of the submarine pipeline span,under the interaction of internal flow and external environmental loads,is established. A constraint-equivalent method is used to deal with the boundary conditions of pipeline span on the linear elastic seabed. Effects of the internal flow velocity and seabed stiffness on the pipeline's lateral deformation and bending stress are studied by the static analysis,while the preliminary relationships between the internal flow velocity and the foundation stiffness to the natural frequency of pipeline span are investigated by the dynamic analysis. It is found that the lateral deformation increases with the increment of internal flow velocity,but decreases with the increment of seabed stiffness. The bending stress at the ends of span increases with the increment of internal fluid velocity and the seabed stiffness,however the stress at the middle of the span shows the converse tendency. Moreover,increasing the seabed stiffness or decreasing the internal flow velocity can lead to higher natural frequency. The dynamics response of midpoint of span at different foundations and internal fluid velocities are also given in this paper.展开更多
The pipe configuration and internal loads along the pipeline during the pipeline laying process have long been the focus of engineers. Most researchers simplify the seabed to be rigid and the water to be calm, ignorin...The pipe configuration and internal loads along the pipeline during the pipeline laying process have long been the focus of engineers. Most researchers simplify the seabed to be rigid and the water to be calm, ignoring the pipe embedment into the seabed and the influence of ocean currents. In this paper, a novel numerical approach is proposed for the laying of pipelines in the so-called J-lay method, taking into account the importance of both pipe embedment and ocean currents. The pipeline is divided into two parts, one part suspended in water, and the other laid on the seabed. The continuity of the two parts at the touch down point (TDP) is guaranteed to make a whole. The feasibility of the model is proved by the comparison between the present model and an analytical model, which shows good agreement in both pipeline configuration and bending moment distribution. Finally, parametric study was performed to consider the influence of current velocity, water depth, top inclination angle, and seabed stiffness, and conclusions are drawn.展开更多
文摘Based on the Hamilton principle,dynamic differential equation of the submarine pipeline span,under the interaction of internal flow and external environmental loads,is established. A constraint-equivalent method is used to deal with the boundary conditions of pipeline span on the linear elastic seabed. Effects of the internal flow velocity and seabed stiffness on the pipeline's lateral deformation and bending stress are studied by the static analysis,while the preliminary relationships between the internal flow velocity and the foundation stiffness to the natural frequency of pipeline span are investigated by the dynamic analysis. It is found that the lateral deformation increases with the increment of internal flow velocity,but decreases with the increment of seabed stiffness. The bending stress at the ends of span increases with the increment of internal fluid velocity and the seabed stiffness,however the stress at the middle of the span shows the converse tendency. Moreover,increasing the seabed stiffness or decreasing the internal flow velocity can lead to higher natural frequency. The dynamics response of midpoint of span at different foundations and internal fluid velocities are also given in this paper.
基金Project (No. 50779061) supported by the National Natural Science Foundation of China
文摘The pipe configuration and internal loads along the pipeline during the pipeline laying process have long been the focus of engineers. Most researchers simplify the seabed to be rigid and the water to be calm, ignoring the pipe embedment into the seabed and the influence of ocean currents. In this paper, a novel numerical approach is proposed for the laying of pipelines in the so-called J-lay method, taking into account the importance of both pipe embedment and ocean currents. The pipeline is divided into two parts, one part suspended in water, and the other laid on the seabed. The continuity of the two parts at the touch down point (TDP) is guaranteed to make a whole. The feasibility of the model is proved by the comparison between the present model and an analytical model, which shows good agreement in both pipeline configuration and bending moment distribution. Finally, parametric study was performed to consider the influence of current velocity, water depth, top inclination angle, and seabed stiffness, and conclusions are drawn.
