拖曳锚在海床中运动特性的大变形有限元分析

拖曳锚由于其承载性能和深水中便于安装被广泛应用于海洋工程系泊系统中,如:适用于悬链式系泊系统的传统拖曳锚和适用于绷紧式系泊系统的法向承力锚。拖曳锚安装过程中涉及诸多运动特性:锚板运动方向、系缆点处拖曳力和拖曳角及运动轨迹。基于大变形有限元分析技术耦合的欧拉-拉格朗日法,并引入缆绳方程,建立起锚-缆绳-海床土耦合作用的有限元分析模型;模拟了拖曳锚在均质和线性强度黏土中的嵌入安装过程,研究了锚板运动方向、系缆点处拖曳力和拖曳角及运动轨迹等运动特性;通过与已有的有限元分析方法及理论方法进行对比,验证了该分析模型的有效性;与已有的有限元分析方法相比,提出的分析模型有效地提高了计算效率。

Large deformation finite element analysis on the kinematic behavior of drag anchors in the seabed

Because of better performance both in pullout capacity and deepwater installation, drag anchors are widely utilized in mooring systems for offshore applications, such as the conventional drag anchor in the catenary mooring system and the vertically loaded plate anchor in the taut-wire mooring system. The penetration behaviors, such as the movement direction of the fluke, the drag force and drag angle at the shackle and the trajectory, are involved during the anchor installation. A large deformation finite element analysis using a coupled Eulerian-Lagrangian approach is performed to simulate the installation process of drag anchors in the clay with uniform and linear strengths, in which a chain equation is introduced to reflect the interaction between the installation line and the anchor. By comparing the results of the published FE method and theoretical method, including the movement direction of the fluke, the drag force and drag angle at the shackle and the trajectory, the efficiency of present work is well verified. Compared with the published FE method, the FE model of present work has a better performance in computational efficiency.