论文标题
使用Kriging对地震脆弱曲线的不确定性定量和全局灵敏度分析
Uncertainty quantification and global sensitivity analysis of seismic fragility curves using kriging
论文作者
论文摘要
地震脆性曲线已被引入，作为地震概率风险评估研究的关键组成部分。它们表达了有条件地进行地震强度度量的机械结构失败的可能性，必须考虑到此类研究中固有的不确定性，所谓的认知不确定性（即来自结构的机械参数的不确定性）和不认真的不确定性（即来自地震基础动作的随机性）。对于基于仿真的方法，我们提出了一种方法，以构建和校准高斯工艺替代模型，以通过传播替代模型不确定性和认识论的非参数地震脆性曲线来估计一个非参数地震脆性曲线。高斯工艺确实具有提出预测因子和评估其预测不确定性的主要优势。此外，我们将此方法扩展到灵敏度分析。提出了全局灵敏度指数，例如聚合的SOBOL指数和基于内核的指数，以了解如何根据每个不确定的机械参数对地震脆性曲线上的不确定性进行分配。这个全面的不确定性定量框架最终应用于由加压水反应堆的管道系统的一部分组成的工业测试案例。
Seismic fragility curves have been introduced as key components of Seismic Probabilistic Risk Assessment studies. They express the probability of failure of mechanical structures conditional to a seismic intensity measure and must take into account the inherent uncertainties in such studies, the so-called epistemic uncertainties (i.e. coming from the uncertainty on the mechanical parameters of the structure) and the aleatory uncertainties (i.e. coming from the randomness of the seismic ground motions). For simulation-based approaches we propose a methodology to build and calibrate a Gaussian process surrogate model to estimate a family of non-parametric seismic fragility curves for a mechanical structure by propagating both the surrogate model uncertainty and the epistemic ones. Gaussian processes have indeed the main advantage to propose both a predictor and an assessment of the uncertainty of its predictions. In addition, we extend this methodology to sensitivity analysis. Global sensitivity indices such as aggregated Sobol indices and kernel-based indices are proposed to know how the uncertainty on the seismic fragility curves is apportioned according to each uncertain mechanical parameter. This comprehensive Uncertainty Quantification framework is finally applied to an industrial test case consisting in a part of a piping system of a Pressurized Water Reactor.
