冲击载荷作用下张力腿平台瞬态动力响应及系泊特性研究

Study on Transient Structural Dynamic Response and Mooring Characteristics of TLP under Impact Load

瞬态冲击荷载作用下平台主体产生大幅运动,易引起系泊系统断裂,危害平台安全。采用数值分析的方法对脉冲荷载作用下张力腿平台主体与系泊系统的耦合动力响应及系泊特性开展了研究。考虑正弦脉冲、三角脉冲及矩形脉冲等典型冲击荷载的影响,借助自编程序对运动微分方程进行了数值求解。重点考察非线性阻尼、脉冲形式、碰撞部位、撞击角度等诸因素对平台瞬态动力特性的影响。研究发现:三种典型脉冲作用下,计及非线性阻尼的纵荡及纵摇响应幅值均小于不考虑非线性阻尼时的计算结果;脉冲峰值影响平台运动响应的幅值;保持相同脉冲冲量时,三种脉冲形式作用下平台时间历程曲线基本一致;碰撞部位及撞击角度对平台动力响应均有较大的影响。

By the effect of transient impact load, motions of the main part of the platform with large-amplitude may occur, which will lead to fracture of mooring system and endanger the security of the platform. In this paper, numerical analysis method is employed to study mooring characteristics and coupling dynamic responses of the main part of the TLP and its mooring system under different impact loads. Responses to three types of impact loads, that is, sine pulse, triangular pulse and rectangular pulse are considered and corresponding differential equations of motions are solved with a self-compiled program. Effects of nonlinear damping, pulse shape, collision position, and angle of attack on transient dynamic characteristics of the platform are considered. It is found that both amplitudes of surge and pitch with nonlinear damping considered are less than that without nonlinear damping. With the same momentum of pulsation, time histories of platform under the three pulse forms are basically in agreement with each other. Dynamical responses of platform are affected by collision position and angle of attack.