Numerical and Experimental Study on the Dynamics of the Tendon/Top Tension Riser System of a Tension-Leg Platform

Abstract

In this study, the dynamics of the tendon/top tension riser (TTR) system of a tension-leg platform (TLP) are investigated through an experiment and by using absolute nodal coordinate formulation (ANCF). First, the model test of the TLP system is conducted in the water tank of Harbin Engineering University to examine the motion response of the TLP and the dynamic response characteristics of the tendon and TTR. The test scale ratio is set to 1: 66.3. Then, on the basis of the ANCF, the stiffness, external load, and mass matrices of the element are deduced to establish the motion equation of the tendon/riser. Finally, the static and dynamic characteristics of the tendon/TTR system of TLP are analyzed systematically by using the ANCF method. The results are compared with commercial software and test results. The motion response of tendon/TTR is affected by the TLP movement and environmental load simultaneously. The analysis proves the effectiveness and accuracy of the ANCF method despite the low number of riser units, suggesting the superiority of the ANCF method for calculating the dynamics of tendon/riser in the field of ocean engineering.

Dynamic behavior of risers under nonlinear oceanic environmental loading

“…Experimental verification was conducted to validate the accuracy of the proposed method [10]. Several studies have demonstrated that both the top tension and internal fluid play crucial roles in influencing the dynamic response of the riser [11][12][13][14]. Yuan et al utilized the force decomposition model to establish the equations of motion for the riser and investigated the effects of vortex force, relative inertia force, and Coriolis force induced by the internal fluid on the riser [15].…”