陡波形立管涡激振动疲劳损伤参数敏感性分析

Parametric Sensitivity Analysis of Fatigue Damage in Steep-Wave Riser Due to Vortex-Induced Vibration

基于柔性杆理论和尾流振子模型计算陡波形立管的涡激振动响应;综合使用S-N曲线法、雨流计数法、Palmgren-Miner线性累积疲劳理论对立管涡激振动导致的疲劳损伤进行计算分析。并以MATLAB为平台编写相应计算程序,将本文计算得到的静力分析结果、固有频率和疲劳损伤分别与专业海工计算软件OrcaFlex和已发表文献进行对比验证。进一步对陡波形立管在涡激振动下的疲劳损伤进行参数敏感性分析,结果表明:浮子段长度、浮力因子、弹性模量、海流速度、波浪高度对陡波形立管疲劳损伤均有较大影响,有望为陡波形立管的实际工程设计提供参考。

The vortex-induced vibration response of the steep-wave riser was calculated based on the slender rods theory and wake oscillator model.The S-N curve method,Rain flow counting method and Palmgren-Miner linear cumulative fatigue theory were used to analyze the fatigue damage of riser under vortex-induced vibration.The corresponding calculation program was written with MATLAB.The results of static analysis,natural frequencies and fatigue damage calculated in this paper are compared with those of professional marine engineering software Orcaflex and published literature to verify.Then the parametric sensitivity analysis of fatigue damage in steep-wave riser due to vortex-induced vibration is carried out by using the program.The results show that the length of float segment,buoyancy factor,elastic modulus,current velocity and wave height have great influence on the fatigue damage of the steep-wave riser.It is expected to provide a reference for the actual engineering design of the steep-wave riser.