基于PC-Kriging模型的极端环境下海上风机基础可靠性分析

Reliability Analysis of Offshore Wind Turbine Foundation in ExtremeEnvironments Based on PC-Kriging Model

为研究基础结构的材料属性和尺寸对单桩式海上风机基础可靠性的影响,提出基于PC-Kriging模型(Polynomial-Chaos-based Kriging,PC-Kriging)和蒙特卡洛模拟(Monte Carlo Simulation,MCS)方法,结合IEGO学习函数建立的单桩式海上风机基础可靠性分析模型,并通过算例验证了该方法的精确性。以50年重现期的海况为极端环境,考虑材料密度、弹性模量和桩腿壁厚的不确定性,进行单桩式海上风机基础在塔筒顶部位移和应力控制两个失效因素下的可靠性分析,并进行全局灵敏度分析。分析结果表明,单桩式海上风机基础失效概率为8.4×10-3,材料密度对可靠性影响可以忽略不计,而材料弹性模量和桩腿壁厚对可靠性影响较大。

In order to study the impact of the material properties and dimensions of the foundation structure on the reliability of single pile offshore wind turbine foundations,a reliability analysis model for single pile offshore wind turbine foundations based on the Polynomial-Chaos-based Kriging model and Monte Carlo simulation method combined with IEGO learning functions was proposed,and the accuracy of the method was verified by numerical examples.Taking the sea state with a return period of 50 years as the extreme environment,considering the uncertainty of material density,elastic modulus,and pile leg wall thickness,the reliability analysis of a single pile offshore wind turbine foundation under two failure factors,namely,tower top displacement and stress control,was conducted,and a global sensitivity analysis was conducted.The results showed that the failure probability of the single pile offshore wind turbine foundation is 8.4×10-3;the effect of material density on reliability can be ignored,while the elastic modulus of material and pile leg wall thickness have a significant impact on the reliability.