在风机极限强度校核问题中，通常采用传统的直接积分法外推求解构件所受的极端载荷。由于传统算法本身的缺陷，在求解海上风机时所需仿真数量急剧增加，给外推造成了困难。为了减少所需的仿真数据，引入反向一阶可靠度方法求解风机极限载荷。将其二维形式环境等值线法与1维最优化方法二分法结合起来，形成一种新的搜索算法。以某Spar型海上浮式风机为例，对其长期载荷进行求解，获得了叶片根部面外弯矩和塔筒基底首尾弯矩分别在1年和20年重现周期下的极端载荷。为了验证计算的准确性，采用计算量更大的直接积分法获取了这2项载荷的长期分布。发现计算结果与超越概率曲线具有较好的吻合度，由此体现出该方法在求解风机特定极限载荷时，不仅具有计算成本的优势同时也有较高的可靠性，为快速求解风机极限载荷提供了一种参考。
In the problem of extreme strength checking of wind turbines, the traditional direct integration method is often used to extrapolate the extreme load of the component. Due to the shortcomings of the traditional algorithm itself, the number of simulations required for offshore wind turbines has increased dramatically, which has caused difficulties in extrapolation. In order to reduce the simulation data required, the Inverse First-Order Reliability Method (IFORM) was introduced. The two-dimensional IFORM (environmental contour method) was combined with the one-dimensional optimization method (dichotomy) to form a new search algorithm. Taking a Spar-type floating offshore wind turbine as an example, the long-term load of it was calculated. And the extreme out-of plane blade root moment and fore-aft tower base moment in 1 year and 20 year return period are acquired. In order to verify the accuracy of the calculation, the long-term distribution of these two loads is obtained by using the direct integration method with greater computational cost. And it is found that the results have good agreement with the transcendental probability curve. This shows that the method not only has the advantage of calculation cost but also high reliability when solving the specific extrme load of wind turbines. So it provides a reference for the rapid calculation of extreme load of wind turbines.
2018,40(9): 99-106 收稿日期：2017-09-12
DOI：10.3404/j.issn.1672-7649.2018.09.019
分类号：TM315
作者简介：周帅(1993-),男,硕士研究生,研究方向为海洋工程设计与分析研究
参考文献：
[1] IEC 61400-3:2009, Wind turbines-Part 3:Design requirements for offshore wind turbines, Edition 1. 0, 2009[S].
[2] IEC 61400-1:2005, Wind turbines-Part 1:Design requirements, Edition 3. 0, 2005[S].
[3] MORIARTY PJ, HOLLEY W, BUTTERFIELD CP. Extrapolation of extreme and fatigue loads using probabilistic methods[EB/OL]. (2004-11)[2017-02]. http://www.nrel.gov/docs/fy05osti/34421.pdf.
[4] SARANYASOONTORN K, MANUEL L. Design loads for wind turbines using the environmental contour method[J]. Journal of Solar Energy Engineering, 2006, 128(4):554-61
[5] SARANYASOONTORN K, MANUEL L. Efficient models for wind turbine extreme loads using inverse reliability[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2004, 92(10):789-804
[6] KARMAKAR D, GUEDES SOARES C. Reliability based design loads of an offshore semi-submersible floating wind turbine[J]. Developments in Maritime Transportation and Exploitation of Sea Resources, Guedes Soares, C and FL Pena, eds, Taylor & Francis Group, London. 2014:919-26.
[7] KARMAKAR D, SOARES C G. Extreme response prediction of offshore wind turbine using inverse reliability technique[C]//ASME 201534th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015:V003T02A065-V003T02A065.
[8] KARMAKAR D, BAGBANCI H, SOARES CG. Long-term extreme load prediction of spar and semisubmersible floating wind turbines using the environmental contour method[J]. Journal of Offshore Mechanics and Arctic Engineering, 2016, 138(2):021601
[9] AGARWAL P, MANUEL L. Simulation of offshore wind turbine response for long-term extreme load prediction[J]. Engineering structures, 2009, 31(10):2236-46
[10] WINTERSTEIN SR, UDE TC, CORNELL CA, et al. Environmental parameters for extreme response:Inverse FORM with omission factors[J]. Proceedings of the ICOSSAR-93, Innsbruck, Austria, 1993:551-7
[11] ROSENBLATT M. Remarks on a multivariate transformation[J]. The Annals of Mathematical Statistics, 1952, 23(3):470-2
[12] JONKMAN J, BUTTERFIELD S, MUSIAL W, et al. Definition of a 5-MW reference wind turbine for offshore system development[EB/OL]. (2009-02)[2017-04]. http://www.nrel.gov/docs/fy09osti/38060.pdf
[13] SARANYASOONTORN K, MANUEL L. On assessing the accuracy of offshore wind turbine reliability-based design loads from the environmental contour method[J]. International Journal of Offshore and Polar Engineering, 2005, 15(02)
[14] JONKMAN BJ. TurbSim User's Guide:Version 1. 06. 00[EB/OL]. (2012-09)[2017-04]. https://nwtc.nrel.gov/system/files/TurbSim.pdf
[15] JONKMAN JM, BUHL Jr ML. FAST user's guide[EB/OL]. (2005-08)[2017-04]. http://wind.nrel.gov/public/bjonkman/TestPage/FAST.pdf
[16] 夏一青, 王迎光. 应用统计外推求解近海风机面外叶根部弯矩最大值[J]. 上海交通大学学报, 2013, 47(12):1968-1973XIA Yi-qing, WANG Ying-guang. Calculation of out-of-plane bending moment at the blade root of offshore wind turbines by statistic extrapolation[J]. Journal of Shanghai Jiaotong University, 2013, 47(12):1968-1973
