This paper presents a recursive system identification method for MDoF structures with tuned mass dampers (TMDs) considering abrupt stiffness changes in case of sudden events, such as earthquakes. Due to supplementary nonclassical damping of the TMDs, the system identification of MDoF + TMD systems disposes a challenge, in particular, in case of sudden events. These identification methods may be helpful for structural health monitoring of MDoF structures controlled by TMDs. A new adaptation formulation of the unscented Kalman filter allows the identification method to track abrupt stiffness changes. The paper, firstly, describes the theoretical background of the proposed system identification method and afterwards presents three parametric studies regarding the performance of the method. The first study shows the augmented state identification by the presented system identification method applied on a MDoF + TMD system. In this study, the abrupt stiffness changes of the system are successfully detected and localized under earthquake, impulse, and white noise excitations. The second study investigates the effects of the state covariance and its relevance for the system identification of MDoF + TMD systems. The results of this study show the necessity of an adaptive definition of the state covariance as applied in the proposed method. The third study investigates the effects of modeling on the performance of the identification method. Mathematical models with discretization of different orders of convergence and system noise levels are studied. The results show that, in particular, MDoF + TMD systems require higher order mathematical models for an accurate identification of abrupt changes.

中文翻译：

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突然事件下具有调谐质量阻尼器的结构的突然刚度变化识别

本文提出了一种带有调谐质量阻尼器（TMD）的MDoF结构的递归系统识别方法，该方法考虑了突然事件（例如地震）的突然刚度变化。由于TMD的非经典阻尼，MDoF + TMD系统的系统识别带来了挑战，特别是在突发事件的情况下。这些识别方法可能有助于监测由TMD控制的MDoF结构的结构健康。无味卡尔曼滤波器的新适应公式允许识别方法跟踪突然的刚度变化。本文首先描述了所提出的系统识别方法的理论背景，然后提出了关于该方法性能的三个参数研究。第一项研究显示了所提出的系统识别方法在MDoF + TMD系统上的增强状态识别。在这项研究中，系统的突然刚度变化已成功检测并定位在地震，脉冲和白噪声激发下。第二项研究调查了状态协方差的影响及其与MDoF + TMD系统的系统识别的相关性。这项研究的结果表明，在所提出的方法中应用自适应定义状态协方差的必要性。第三项研究调查了建模对识别方法性能的影响。研究了具有不同收敛阶数和系统噪声水平离散的数学模型。结果表明，特别是，