With the motivation to overcome the shortcomings of the Rosenblatt inverse-first-order reliability environmental contour method (IFORM), in this study, the use of bivariate kernel density estimation with smoothed cross-validation bandwidth selection method is proposed for generating more accurate environmental contour lines. The environmental contour lines at a chosen offshore site obtained by using the proposed new method were compared with those obtained by using the Rosenblatt IFORM, and the accuracy and effectiveness of the proposed new method have been fully and clearly substantiated. Next, the 50 year extreme structural dynamic responses of a monopile-supported 5 MW offshore wind turbine installed at this chosen offshore site based on the proposed new method and the Rosenblatt IFORM were calculated. Analysing the calculated results, it can be found that the 50 year extreme fore−aft shear force value based on the 50 year extreme sea state obtained using the proposed new method is 78.9% larger than the corresponding value obtained based on the Rosenblatt IFORM. The calculation results in this paper were further systematically analysed and compared, and the necessity and importance of using more realistic environmental contour lines (such as those generated using the proposed new method) have been finally highlighted.

中文翻译：

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海上风电机组结构安全可靠性分析新方法

为了克服 Rosenblatt 逆一阶可靠性环境轮廓法 (IFORM) 的缺点，在本研究中，提出了使用双变量核密度估计和平滑交叉验证带宽选择方法来生成更准确的环境轮廓线。将使用所提出的新方法获得的选定近海场地的环境等高线与使用 Rosenblatt IFORM 获得的环境等高线进行了比较，并且所提出的新方法的准确性和有效性得到了充分而明确的证实。接下来，基于所提出的新方法和 Rosenblatt IFORM 计算了安装在这个选定的海上站点的单桩支撑的 5 MW 海上风力涡轮机的 50 年极端结构动态响应。分析计算结果，可以发现，采用新方法得到的基于 50 年极端海况的 50 年极端前后剪力值比基于 Rosenblatt IFORM 得到的对应值大 78.9%。对本文的计算结果进行了进一步的系统分析和比较，最终强调了使用更真实的环境等高线（如使用所提出的新方法生成的等高线）的必要性和重要性。