基于Winterstein/Jensen方法的深水海洋平台动力响应分析

Dynamic response analysis of deepwater offshore platform based on Winterstein/Jensen method

深水海洋平台整体刚度小,固有周期更加接近波浪的高能量区域,动力响应的影响较一般水深的平台更为显著。以往通过多个随机波浪响应的最大动基底剪力和最大静基底剪力之比的均值确定DAF(动力放大系数)的方法(均值法)缺乏规范和理论依据。基于SNAME规范推荐的Winterstein方法,给出了深水平台的MPME(最可能极值)和DAF的计算要求和过程,结合实际平台案例进行分析并与均值法结果进行了对比,指出了Winterstein方法的优点,可作为深水海洋平台动力响应分析的推荐分析方法,为平台结构设计提供参考。

The overall stiffness of a deepwater offshore platform is small,resulting in a natural period closer to that of the high-energy region of waves and an influence of a dynamic response more significant than that of the dynamic response of a platform at a normal depth.The previous method determines the dynamic amplification factor(DAF)by the mean value of the ratios of the maximum dynamic base shears of the responses to multiple random waves to the maximum static base shears of those responses,and this mean value method lacks specification and theoretical bases.On the basis of the Winterstein method recommended by the specifications defined by the Society of Naval Architects and Marine Engineers(SNAME),this paper proposes calculation requirements and a calculation process for the most probable maximum extreme(MPME)and DAF of a deepwater platform.Then,it analyzes an actual platform,compares the results with those of the mean value method,and points out the advantages of the Winterstein method.The proposed method can serve as a recommended analysis method for dynamic response analysis of deepwater offshore platforms and provide a reference for platform structure design.