Large Deformation Finite Element Study On The Comprehensive Kinematic Behavior Of Deepwater Anchors In The Seabed

Deepwater anchor is the core component of deepwater mooring system.With the development of new concepts and technologies in the field of deepwater mooring,the kinematic behavior of deepwater anchors in the seabed becomes more complicated.Due to the lack of understanding of the mechanism of the comprehensive kinematic behavior of deepwater anchors in the seabed,the theoretical method is hard to undertake.Meanwhile,the test is also limited by its economy and feasibility.In this condition,it is of great significance for putting forward a large deformation finite element analysis and applying it to the study on the comprehensive kinematic behavior of deepwater anchors.A large deformation finite element analysis using a Coupled Eulerian-Lagrangian approach is performed to simulate the kinematic behavior of deepwater anchors in the seabed,in which a chain equation is introduced to reflect the interaction between the installation line and the anchor by the subroutine VUAMP.Firstly,the large deformation finite element analysis is applied to simulate the installation process of drag anchors in the clay with uniform and linear strengths.By comparing with results of the published FE method,including the movement direction of the fluke,the 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 on the computational efficiency.Secondly,application in predicting the keying of suction embedded plate anchors is carried out to study anchor trajectory and inclination during the keying process.By comparing with the published results,the validity of the FE model is well verified.Finally,a parametric analysis is performed to study the effects of soil strength gradient,initial embedment,chain inclination and the coefficient of chain equation on the kinematic behavior of OMNI-Max anchor.By analyzing anchor trajectory and inclination,the mechanism of the kinematic behavior of OMNI-Max anchor is better understood.