直立式水下驻留平台座底稳定性分析

Analysis for Bottom-seated Stability of Vertical Underwater Mooring Platform

摘要:

建立了适用于大攻角状态的水下平台六自由度数学模型,使用四元数替代欧拉角描述平台姿态,以消除某些特殊情况下因平台姿态变化或个别欧拉角不确定性导致的运动方程奇异现象。 基于弹性力学相关理论建立符合海底真实物理特性的弹塑性数值模型,将座底平台-海底间交互作用与平台空间运动模型相结合,预报直立式平台座底驻留后对海流作用的运动响应,分析平台座底稳定性,为后续设计提供参考。

关键词:水下无人平台;座底稳定性;海底交互作用;姿态四元数;动态分析;模型仿真

Abstract:

A six degree of freedom numerical simulation model of unmanned underwater platform is established, which is suitable for large angle of attack. In addition, quaternion-based platform attitude model is adopted to substitute the traditional Euler- angle form so as to eliminate singular phenomena of motion equation under some special circumstances, namely platform attitude changes in large amplitude or some specific uncertain Euler-angles. On the basis of correlation theory of elastic mechanics, an elas- tic-plastic numerical seabed model which complies well with actual seabed physical characteristics is established, Combining the bot- tom-seated platform-seabed interaction with the platform’ s space motion model, the motion response of vertical platform bottom- seated mooring to ocean current effect is predicted, and the bottom-seated stability of platform is analyzed to provide references for subsequent design.

Key words:unmanned underwater platform; bottom-seated stability; seabed interaction; attitude quaternion; dynamic anal- ysis; model simulation