考虑参数不确定性的海上风电结构模型修正方法

Stochastic Model Updating for Offshore wind Turbines Considering Parametric Uncertainties

由于建模误差、参数不确定性等原因,海上风电结构数值模型通常与真实结构存在一定的误差,影响后续基于模型的研究,故需要对海上风电结构模型进行模型修正。首先假设待修正参数和结构动力响应特征服从高斯分布,将不确定模型修正问题转化为均值和标准差的修正问题;其次,构造以待修正参数为输入、频率为输出的Kriging模型,并以KL(Kullback-Leibler)散度量化实测频率与修正频率分布之间的差异,通过多目标优化算法求解待修正参数的均值和标准差;最后,通过海上风电结构数值模型进行模型修正。结果表明,考虑参数不确定性的随机有限元模型修正方法能有效修正海上风电结构参数的均值和标准差。

Due to modeling errors,parameter uncertainties,and other factors,numerical models of offshore wind turbines often exhibit discrepancies from the actual structures,which can impact subsequent model-based research.Therefore,it is necessary to perform structural model updating for offshore wind turbines(OWTs).Firstly,it is assumed that the parameters to be updated and the dynamic response characteristics of the structure follow a Gaussian distribution,transforming the uncertain model updating problem into a problem of correcting the mean and standard deviation.Secondly,a Kriging model is constructed with the parameters to be corrected as input and frequency as output.The Kullback-Leibler(KL)divergence is used to quantify the differences between the measured frequency and the corrected frequency distributions.A multi-objective optimization algorithm is then employed to solve for the mean and standard deviation of the parameters to be corrected.Finally,an OWT numerical model is updated based on the obtained results.The results indicate that the stochastic model updating method,considering parametric uncertainties,can effectively update the mean and standard deviation of structural parameters.