Abstract Hybrid Simulation is a dynamic response simulation paradigm that merges physical experiments and computational models into a hybrid model. In earthquake engineering, it is used to investigate the response of structures to earthquake excitation. In the context of response to extreme loads, the structure, its boundary conditions, damping, and the ground motion excitation itself are all subjected to large parameter variability. However, in current seismic response testing practice, Hybrid Simulation campaigns rely on a few prototype structures with fixed parameters subjected to one or two ground motions of different intensity. While this approach effectively reveals structural weaknesses, it does not reveal the sensitivity of structure’s response. This thus far missing information could support the planning of further experiments as well as drive modeling choices in subsequent analysis and evaluation phases of the structural design process. This paper describes a Global Sensitivity Analysis framework for Hybrid Simulation. This framework, based on Sobol’ sensitivity indices, is used to quantify the sensitivity of the response of a structure tested using the Hybrid Simulation approach due to the variability of the prototype structure and the excitation parameters. Polynomial Chaos Expansion is used to surrogate the hybrid model response. Thereafter, Sobol’ sensitivity indices are obtained as a by-product of polynomial coefficients, entailing a reduced number of Hybrid Simulations compared to a crude Monte Carlo approach. An experimental verification example highlights the excellent performance of Polynomial Chaos Expansion surrogates in terms of stable estimates of Sobol’ sensitivity indices in the presence of noise caused by random experimental errors.

中文翻译：

---

混合仿真的全局敏感性分析框架

摘要 混合仿真是一种将物理实验和计算模型融合为混合模型的动态响应仿真范式。在地震工程中，它用于研究结构对地震激发的响应。在响应极端载荷的情况下，结构、其边界条件、阻尼和地震动激励本身都受到很大的参数变化。然而，在当前的地震响应测试实践中，混合模拟活动依赖于一些具有固定参数的原型结构，这些原型结构受到一两个不同强度的地面运动的影响。虽然这种方法有效地揭示了结构的弱点，但它并没有揭示结构响应的敏感性。迄今为止，这些缺失的信息可以支持进一步实验的规划，并在结构设计过程的后续分析和评估阶段推动建模选择。本文介绍了混合仿真的全局灵敏度分析框架。由于原型结构和激励参数的可变性，该框架基于 Sobol 的灵敏度指数，用于量化使用混合仿真方法测试的结构的响应灵敏度。多项式混沌扩展用于替代混合模型响应。此后，Sobol 的灵敏度指数是作为多项式系数的副产品获得的，与粗略的 Monte Carlo 方法相比，需要减少混合模拟的数量。