Adding a virtual mass is an effective method for damage identification. It can be used to obtain a large amount of information about structural response and dynamics, thereby improving the sensitivity to local damage. In the current research approaches, the virtual mass is determined first, and then the modal characteristics of the virtually modified structure are identified. This requires a wide frequency band excitation; otherwise the crucial modes of the modified structure might be out of the band, which would negatively influence the modal analysis and damage identification. This paper proposes a method that first determines the target frequency and then estimates the corresponding value of the additional virtual mass. The target frequency refers to the desired value of the natural frequency after the virtual mass has been added to the structure. The virtual masses are estimated by tuning the frequency response peaks to the target frequencies. First, two virtual mass estimation methods are proposed. One is to directly calculate the virtual mass, using the frequency‐domain response at the target frequency point only, whereas the second method estimates the mass using a least‐squares fit based on the frequency‐domain response around the target frequency. Both proposed methods utilize merely a small part of the frequency domain. Therefore, an impulse, a simple harmonic, or a narrow spectral excitation can be used for damage identification. Finally, a numerical simulation of a simply supported beam and experiments of a frame structure and a truss structure are used to verify the effectiveness of the proposed method.

中文翻译：

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估计虚拟质量以识别结构损伤

添加虚拟质量是一种有效的损伤识别方法。它可用于获取有关结构响应和动力学的大量信息，从而提高对局部破坏的敏感性。在当前的研究方法中，首先确定虚拟质量，然后确定虚拟修改后的结构的模态特征。这需要宽频带的激励。否则，修改后的结构的关键模式可能会超出范围，这会对模式分析和损伤识别产生负面影响。本文提出了一种方法，该方法首先确定目标频率，然后估计附加虚拟质量的相应值。目标频率是指将虚拟质量添加到结构后的固有频率的期望值。通过将频率响应峰值调整为目标频率来估算虚拟质量。首先，提出了两种虚拟质量估计方法。一种是仅使用目标频率点上的频域响应直接计算虚拟质量，而第二种方法是基于目标频率附近的频域响应，使用最小二乘拟合估计质量。两种提出的方​​法仅利用频域的一小部分。因此，可以将脉冲，简单谐波或窄谱激励用于损伤识别。最后，