采用功率谱研究了海上风力机的随机风浪荷载,同时根据JCSS(结构安全度联合委员会)准则探讨了海上风机随机风浪荷载的组合问题。为满足时域内海上风机动力反应计算的需求,采用谐波叠加法研究了随机风浪荷载时程的计算方法。对于风荷载,计算过程中考虑了风场的空间相干性和风剪效应;对于波浪荷载,提出了考虑海浪波面高程变化时波浪荷载的计算方法。计算结果表明,不考虑波面变化,将低估波峰处的波浪荷载,而高估波谷处的波浪荷载;对于海上风机而言,以风荷载作为主要荷载进行风浪组合得到的计算结果偏于安全;同时通过模拟荷载的计算谱与目标谱的比较,表明了该文随机荷载时程模拟的正确性。
As the strong random of wind and wave loads, the power spectrum was used to study the random wave and wind loads and the JCSS code was used to investigated the wind and wave loads combination. To satisfy calculating the dynamic response of offshore wind turbine in time domain, the harmony superposition method was used to calculate the random wind and wave loads time history. The spatial coherence and the wind shear effects were included in the calculation of random wind loads time history, and a new calculation method was presented to considering the wave surface elevation variation effects in calculating the random wave loads time history. The calculation results shown that the random wave loads are underestimated at the wave peak and are overestimated at the wave trough as not considering the wave surface elevation variation effects. For the offshore wind turbine, the calculation results tend to safety when the wind loads was chosen as main loads to combine with the wave loads. The correctness of simulating the random loads time history was testified by comparing the calculation spectrum and the target spectrum.