The technology of damage evaluation based on data collected by sensors has become an important topic in the field of structural engineering This paper presents an improved generalized flexibility method for sensor placement and damage evaluation. Compared with the existing methods, the main improvements of the proposed method lie in three aspects. The first one is to replace mass-normalized mode shapes with arbitrary-scaled mode shapes since that only the latter can be obtained in modal testing under ambient excitation. The second one is to combine the generalized flexibility sensitivity with the frequency sensitivity to obtain more equations. The third one is to use a new regularized generalized inverse technique for computing the unknowns more accurately. Sensor placement based on the improved generalized flexibility method can be divided into three steps. Firstly, the number of sensors can be predicted by a simple formula derived by the principle of the number of equations should close to the number of unknowns as far as possible. Secondly, the key components of the whole structure are determined based on their contributions to the global generalized flexibility change. Thirdly, the sensor positions can be obtained according to the common nodes of those key components. Overall, the proposed method is simple and convenient since it only needs environment excitation and a few sensors. The results of numerical and experimental examples show that the proposed method can successfully evaluate structural damage with a few sensor signals.

中文翻译：

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通过改进的广义灵活性进行传感器放置和结构损伤评估


基于传感器收集的数据进行损伤评估技术已成为结构工程领域的一个重要课题。本文提出了一种改进的广义柔性传感器放置和损伤评估方法。与现有方法相比，该方法的主要改进在于三个方面。第一个是将质量归一化模态形状替换为任意尺度模态形状，因为在环境激励下的模态测试中只能获得后者。第二个是将广义柔度灵敏度与频率灵敏度结合起来以获得更多方程。第三个是使用一种新的正则化广义逆技术来更准确地计算未知数。基于改进的广义柔性方法的传感器放置可分为三个步骤。首先，根据方程个数应尽可能接近未知数个数的原则，通过简单的公式推导出传感器的个数。其次，根据其对全球广义灵活性变化的贡献来确定整个结构的关键组成部分。第三，根据这些关键部件的公共节点可以得到传感器位置。总的来说，所提出的方法简单方便，因为它只需要环境激励和少量传感器。数值和实验结果表明，该方法可以利用少量传感器信号成功评估结构损伤。