深水铰接塔平台的非线性动力特性分析

研究了铰接塔平台在波浪和海流作用下的非线性动力特性。将平台顶部工作单元简化为集中质量,塔柱和浮力仓简化为均匀直杆,建立了铰接塔平台动力分析模型。考虑海流和波浪对平台的作用,应用Morison公式计算铰接塔平台瞬时位置所受水动力,依据拉格朗日原理建立了铰接塔平台的强非线性运动方程。分别考虑波浪作用和波流联合作用,采用数值计算的方法研究了铰接塔平台超谐共振和混沌运动。研究表明,波流联合作用下平台的超谐共振运动响应增加,在大幅和较高频率波浪激励下,平台系统出现混沌运动。

NONLINEAR DYNAMIC CHARACTERISTIC ANALYSIS OF ARTICULATED TOWER PLATFORM IN THE DEEP WATER

The nonlinear dynamics characteristic of articulated tower platform (ATP) subjected to waves and current loads is studied. The units on the top of ATP is simplified into one concentrated mass. The tower and buoyancy cabinet are simplified into a uniform rigid bar. The model for ATP is put forward for dynamics analysis. Considering current and wave loads, hydrodynamic force is evaluated at the instantaneous position for the ATP by Morison formula, the highly nonlinear motion equation is established by Lagrange principle. The super-harmonic resonance and chaos motion of ATP are investigated using numerical method with wave loads and combined wave-current loads considered separately. The results show that super-harmonic resonance motion response of ATP increases under combined wave-current loads, and chaos motion occurs under high frequency and big amplitude wave excitation.