In this study, we propose a novel surrogate modelling approach to efficiently and accurately approximate the response of complex dynamical systems driven by time-varying Recently, there has been increased interest in assessing the seismic fragility of industrial plants and process equipment. This is reflected in the growing number of studies, community-funded research projects and experimental campaigns on the matter.Nonetheless, the complexity of the problem and its inherent modelling, coupled with a general scarcity of available data on process equipment, has limited the development of risk assessment methods. In fact, these limitations have led to the creation of simplified and quick-to-run models. In this context, we propose an innovative framework for developing state-dependent fragility functions. This new methodology combines limited data with the power of metamodelling and statistical techniques, namely polynomial chaos expansions (PCE) and bootstrapping. Therefore, we validated the framework on a simplified and inexpensive-to-run MDoF system endowed with Bouc-Wen hysteresis.Then, we tested it on a real nonstructural industrial process component. Specifically, we applied the state-dependent fragility framework to a critical vertical tank of a multicomponent full-scale 3D steel braced frame (BF). The seismic performance of the BF endowed with process components was captured by means of shake table campaign within the European SPIF project. Finally, we derived state-dependent fragility functions based on the combination of PCE and bootstrap at a greatly reduced computational cost.

翻译：本研究提出了一种新颖的代理建模方法，以高效且准确地逼近受时变因素驱动的复杂动力系统响应。近年来，工业厂房及工艺设备地震易损性评估日益受到关注，相关研究、社区资助项目及试验活动数量不断增加。然而，该问题的复杂性及其固有建模挑战，加之工艺设备可用数据的普遍匮乏，限制了风险评估方法的发展。事实上，这些局限性促使了简化快速模型的开发。在此背景下，我们提出了一种创新框架以构建状态依赖易损性函数。该方法将有限数据与元建模及统计技术（即多项式混沌展开PCE与自助法）相结合。我们首先在一个配备Bouc-Wen滞回模型的简化低计算成本多自由度（MDoF）系统上验证了该框架，随后将其应用于真实非结构工业工艺构件。具体而言，我们将状态依赖易损性框架应用于欧洲SPIF项目振动台试验中一个由多组件构成的足尺三维钢支撑框架（BF）的关键立式储罐。最终，基于PCE与自助法的组合，我们以极低计算成本推导出了状态依赖易损性函数。