半潜式平台波浪砰击荷载数值分析

Numerical analysis of wave slamming load on semi-submersible platform

波浪-半潜式平台-系泊系统在不同空间尺度的动力因素具有强非线性,导致波浪砰击荷载峰值、持续时间难以预测。基于光滑粒子法,建立了波浪-浮式结构-系泊系统多体耦合动力分析模型,并将该模型计算结果与文献实验结果进行了对比,验证了其计算的正确性。采用该模型分析了波浪、浮式结构及系泊系统耦合作用下砰击荷载的发展历程,对比了聚焦波与线性波作用下砰击荷载的分布特征,结果表明:静水面以上,聚焦波对半潜式平台立柱的砰击荷载显著大于线性波的砰击荷载,聚焦波砰击荷载是线性波砰击荷载的3~5倍,但静水面以下,2种波浪砰击荷载差异相对较小;线性波作用下,半潜式平台迎浪侧和背浪侧的系泊缆拉力值差异较小,聚焦波作用下迎浪侧的拉力值则显著大于背浪侧,同时大于线性波作用下的拉力值,约为线性波作用下的1.9倍。研究结果为浮式平台波浪砰击荷载安全系数选取提供了参考。

The dynamic factors of wave-semi-submersible platform-mooring system have strong nonlinearity at different spatial scales,resulting in the difficulties of predicting the peak and duration of wave slamming load.Based on the smooth particle method,a multi-body coupling dynamic analysis model of wave-floating structure-mooring system is established.By comparing the calculated results with the experimental results in the literature,the correctness of the model is verified.The development process of wave slamming load under the coupling of wave,floating structure and mooring system is analyzed,and the distribution characteristics of slamming loads under the actions of focused wave and regular wave are compared.The results show that above the still water surface the slamming load of focused wave on the semi-submersible platform column is significantly greater than that of regular wave,and the slamming load of the focused wave is 3-5 times that of the regular wave.But below the still water surface the difference between the two types of wave slamming loads is relatively small.Under the action of regular waves,the difference between the mooring line tensions on the head wave side and the back wave side of the semi-submersible platform is small.But the tension on the head wave side is significantly greater than that on the back wave under the action of focused waves,which is about 1.9 times of that under the action of regular waves.The research results provide a reference for the selection of safety factor of wave slamming load on floating platforms.