基于多尺度有限元-机器学习耦合的风电基础结构损伤演化
Damage evolution of wind power foundation structure based on multi-scale finite element machine learning coupling
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摘要: 目的:耦合多尺度有限元与机器学习模型,分析风电基础结构损伤演化机制。方法:分别建立风电基础结构的宏观尺度连续介质模型与微观尺度非均质细观构型模型,通过界面位移协调与应力平衡约束实现宏-微观多尺度模型的耦合分析,获取结构在不同荷载工况下关键部位的应力、应变场及损伤起始-扩展过程的细观演化信息;将有限元计算所得的时序力学特征作为输入变量,构建基于随机森林的机器学习模型,并利用多尺度模拟样本数据进行模型训练与超参数优化,实现从局部力学响应到全局损伤状态的端到端非线性映射。结果:在极端荷载作用下,风电基础结构的关键连接区域损伤演化呈现明显的尺度跨越特征;局部损伤累积会导致基础整体刚度与承载力呈现非线性衰减趋势,尤其在刚度退化阈值超过15%后,承载力下降速率显著加剧。结论:所建立的多尺度有限元-机器学习耦合框架可有效规避纯数值模拟的计算发散风险与纯数据驱动的物理机制缺失问题,为高烈度风震联合作用下风电基础结构的损伤容限设计与运维决策提供理论支撑。Abstract: Objective: To couple multi-scale finite element and machine learning models to analyze the damage evolution mechanism of wind power foundation structures. Method: Macro scale continuous medium models and micro scale heterogeneous micro configuration models of wind power infrastructure are established separately. The coupling analysis of macro micro multi-scale models is achieved through interface displacement coordination and stress balance constraints to obtain micro evolution information of stress, strain fields, and damage initiation propagation processes of key parts of the structure under different load conditions; Using the temporal mechanical characteristics obtained from finite element calculations as input variables, a machine learning model based on random forest is constructed. Multi scale simulated sample data is used for model training and hyperparameter optimization, achieving end-to-end nonlinear mapping from local mechanical response to global damage state. Result: Under extreme loads, the damage evolution of key connection areas in wind power foundation structures exhibits significant scale crossing characteristics; The accumulation of local damage can lead to a non-linear decay trend in the overall stiffness and bearing capacity of the foundation, especially after the stiffness degradation threshold exceeds 15%, the rate of decrease in bearing capacity significantly intensifies. Conclusion: The established multi-scale finite element machine learning coupling framework can effectively avoid the computational divergence risk of pure numerical simulation and the lack of physical mechanisms driven by pure data, providing theoretical support for the damage tolerance design and operation decision-making of wind power foundation structures under high-intensity wind and earthquake combined action.
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