| Abstract: | The anchorage system for mid-ocean loading or production consists of an articulated tower for mooring the tanker. Flexible risers are also essential components of the anchorage system. The present paper provides a state-of-the-art review on articulated storage systems and flexible risers, giving theoretical background for the development of computer software for the static analysis of flexible risers.In the state-of-the-art review for flexible risers, various analysis techniques for elastic lines and flexible risers under self-weight, current and wave forces are presented. The dynamic response of the flexible riser, including vortex-induced oscillations, is also outlined.The literature concerning the articulated tower and tanker is relatively scarce. Available works related only to dynamic responses of articulated towers. The combined response of tower and tanker is only studied by Chakrabarti and Cotter (1978), Analysis of a tower-tanker system. In Proceedings of the 10th Offshore Technology Conference, OTC 3202, pp. 1301–1310] in a limited sense. The review of these works is summarised relevant to this paper.In the end, the static analysis of the flexible riser under its self-weight and current is presented using a finite difference approach. The problem essentially involves geometrical non-linearity, which is tackled with the help of an iterative solution based on modified Newton-Raphson technique. The theoretical formulation presented is being used to develop the computer software for the static analysis of the flexible risers. |
