This paper proposes a new method for online identification of damping properties in seismically excited structures. It is a major extension of the recently developed Virtual Synchronization Method (VSM) with the following benefits: Its formulation is simpler and contains fewer design parameters. It includes a sufficient condition which can be validated online to ensure whether it is successful in identification of the structural damping model. It is assumed that the parameters of the damping model are fully unknown whereas the stiffness and mass of the structure are known. Online measurements of the ground motion acceleration, displacement and velocity vectors are available. Using these data, a virtual copy of the original structure is created. Then, the error between the states of the two systems is calculated. It is employed for designing an appropriate virtual controller which forces the virtual system to synchronize with the original one. Consequently, the states of these two systems are used to propose a nonlinear adaptive law to estimate the unknown parameters of the damping model. Provided numerical examples show that the proposed online identification method is efficiently fast, promising and worthy of further studies.

中文翻译：

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一阶虚拟同步：存在地震激励时结构阻尼在线识别的新方法

本文提出了一种在线识别地震激发结构阻尼特性的新方法。它是最近开发的虚拟同步方法 (VSM) 的主要扩展，具有以下优点： 它的公式更简单，包含的设计参数更少。它包括一个可以在线验证的充分条件，以确保它是否成功地识别了结构阻尼模型。假设阻尼模型的参数是完全未知的，而结构的刚度和质量是已知的。可以在线测量地面运动加速度、位移和速度矢量。使用这些数据，可以创建原始结构的虚拟副本。然后，计算两个系统的状态之间的误差。它用于设计一个适当的虚拟控制器，强制虚拟系统与原始系统同步。因此，这两个系统的状态被用来提出非线性自适应律来估计阻尼模型的未知参数。提供的数值例子表明，所提出的在线识别方法高效、快速、有前途，值得进一步研究。