Spar平台垂荡-纵摇耦合运动失稳机理  

Instability mechanism of coupled heave-pitch motions for Spar platform

作　　者：刘利琴[1] 唐友刚[1] 王文杰[1] 

机构地区：[1]天津大学建筑工程学院船舶与海洋工程系,天津300072

出　　处：《海洋工程》2009年第2期29-35,共7页The Ocean Engineering

基　　金：国家863资助项目(2007AA09Z30);国家自然科学基金重点资助项目(50639030);国家自然科学基金资助项目(50879057)

摘　　要：研究参数激励和强迫激励共同作用下Spar平台垂荡-纵摇耦合运动的失稳机理。考虑静稳性和排水体积的变化,推导平台的垂荡回复力和纵摇回复力矩表达式,建立规则波浪中平台垂荡-纵摇耦合的运动方程。以经典Spar平台为例,分析平台垂荡-纵摇耦合运动发生马休类型不稳定运动的条件以及平台运动失稳的形式,给出波高和波浪周期平面上平台因大幅运动失稳的参数域。结果表明,当波高相对较小时,波浪的临界周期接近于垂荡固有周期,平台失稳的形式为马休失稳;当波高相对较大时,波浪的临界周期远离垂荡固有周期,平台由于大幅摇摆运动而失稳。The instability mechanism of coupled heave-pitch motions for Spar platform under both parmnetric excitation and forced excitation is studied. Considering the static stability and the change of the displacement volume, the formulas of heave restoring force and the pitch restoring moment are derived and the equations of the coupled heave-pitch motions are established in the regular waves. Taking a classic spar platform as an example, the occurrence condition for the Mathieu unstable motion and the instability form of coupled heave-pitch motions are analyzed, the parameter domain of the wave height and the wave period for the instable motion are provided. It is found that for the lower wave height, the critical wave period is close to the heave natural period and the Mathieu instability is the main reason for the instability of platform; for the higher wave height, the critical wave period is far away from the heave natural period and the large amplitude motion is the main reason for the instability of platform.

关 键 词：SPAR平台 垂荡-纵摇耦合运动 马休不稳性 内共振 失稳机理 

分 类 号：P751[交通运输工程—港口、海岸及近海工程]