海洋立管综合环境条件设计标准研究

Study on combined design criteria for marine risers conveying flowing fluid

首先用有限单元法推导海洋输液立管在外界环境荷载条件下的侧向振动微分方程。对渤海某海区的 15次风暴过程作了抽样分析 ,得到以波高为主时的波高、流速序列和以流速为主时的波高、流速序列 ,并对其进行了Weibull、Gumbel、Log nor mal等适线分析 ,以确定各序列的最优分布形式及相应的特征值。用重点抽样法进行随机模拟得到联合概率为百年一遇的波高和流速。针对浅海固定式平台铰接的海洋输液立管 ,以最大应力为控制条件确定其联合设计标准 ,并与其它方法作了比较 ,得到一些有益的结论。

Based on the small deflection theory, the lateral motion equation of a marine riser conveying flowing fluid subjected to environmental loads is developed by use of finite element method. Sampling analysis is made on 15 storms of Bohai Sea to obtain sequences of wave height and current velocity dominated by wave and current respectively. Then the optimal types of distribution and corresponding characteristic values are determined. Simulation of an important sampling method is made to get the wave height and current velocity whose joint probability is 0 01. For the marine riser hinged on fixed platforms in shallow sea, the maximum stress of riser is regarded as the control condition to determine the combined design criteria and comparison is made with other methods.