深水顺应式铰接塔平台的非线性运动特性分析

ANALYSIS OF NONLINEAR DYNAMICS BEHAVIORS OF COMPLIANT ARTICULATED TOWER PLATFORM IN THE DEEP WATER

研究了静水中顺应式铰接塔平台的运动特性。将平台简化为顶部有集中质量绕海底铰接点作平面运动的单自由度体系,考虑铰接点的库伦摩擦、塔柱的结构阻尼及海流对平台的作用,采用拉格朗日方程建立了铰接塔平台的强非线性运动方程。采用Taylor级数展开微分方程,对平台的运动响应进行了数值模拟。计算表明铰接塔平台的固有周期接近低频波浪周期,可能发生大幅慢漂运动;同时揭示了平台平衡位置与海流流速之间的关系,以及库仑摩擦对静平衡位置的影响。

The paper studies the nonlinear free vibration behaviors for the compliant articulated tower platform in the still deep water.The platform is modeled as the single freedom degree system with concentrated mass as the top,which rotates about the hinge on the foundation.The highly nonlinear motion equation is established by Lagrangian Equations considering coulomb friction,and viscous structural damping as well as the nonlinear fluid dynamics of current.The equation is expanded by the application of Taylor series and solved by numerical simulation.The results indicate the natural period of ATP closes to the period of low frequency wave and the motion of slow drift at great amplitude is likely appear,and the nonlinear relation between equilibrium position of platform and the flow velocity and the influence of coulomb friction on equilibrium are revealed.