ABSTRACT

The float-over installation method has become the best solution to offshore heavy topsides installations due to its flexibility and low cost. Dynamically positioned vessels can accurately keep position and track the predefined path with the help of thrusters, which eliminate the rigid requirements on auxiliary tugboats andmooring system. A precise control strategy is of critical importance to ensure the barge entering the slot successfully while keeping the impact with fenders within an acceptable limit. This paper establishes a time domain method to simulate the nonlinear motions during the docking stage. The barge is exposed to wind, wave and current forces to model the practical installation environment, and interactions between the barge and sway fenders are carefully taken into consideration. A model test is further conducted to validate the simulation results. Comparisons show that the proposed simulation programme can correctly simulate the docking stage of barge and predict the impact force of sway fenders.

摘要

浮动式安装方法由于其灵活性和低成本而已成为海上重型顶面安装的最佳解决方案。动态定位的船只可以借助推进器准确地保持位置并跟踪预定路径，从而消除了对辅助拖船和系泊系统的刚性要求。精确的控制策略对于确保驳船成功进入狭槽同时将挡泥板的冲击保持在可接受的范围内至关重要。本文建立了一种时域方法来模拟对接阶段的非线性运动。驳船受到风，波浪和潮流的影响，以模拟实际的安装环境，并仔细考虑了驳船和防撞板之间的相互作用。进一步进行模型测试以验证仿真结果。比较表明，所提出的仿真程序能够正确模拟驳船的停靠阶段，并能预测防撞护舷的冲击力。