Zhu Jianjian, Wang Yishou, Qing Xinlin
School of Aerospace Engineering, Xiamen University, Xiamen 361002, China.
Nanomaterials (Basel). 2019 Sep 5;9(9):1268. doi: 10.3390/nano9091268.
In order to monitor the health condition of structures in a more sensitive and accurate way, a novel and universal methodology called direct coupling mechanical impedance (DCMI) for characteristic signatures extraction is presented in this paper. This methodology is used to obtain DCMI signatures from measured raw signatures (RSs) with the surface-bonded piezoelectric sensors (PZT), which is developed from a pertinent electromechanical impedance (EMI) theoretical model for surface-bonded circular PZT. The proposed DCMI methodology has the advantages of simple calculation and magnifying the signatures when compared with the existing methods. Combining the extracted DCMI signatures with the root mean square deviation (RMSD) index is able to quantify the correlation between the health condition and the signatures variation more effectively. To verify the effectiveness of proposed DCMI methodology, experiments are conducted on aluminum plates and a part of fuselage in detail. The experimental results sufficiently demonstrate that the presented universal DCMI methodology possesses better sensitivity than the raw signatures when utilized for evaluating the health condition of metallic structures, including those made of metal-matrix nanomaterials.
为了以更灵敏、准确的方式监测结构的健康状况，本文提出了一种名为直接耦合机械阻抗（DCMI）的新颖通用的特征信号提取方法。该方法用于通过表面粘贴压电传感器（PZT）从测量的原始信号（RSs）中获取DCMI信号，它是基于表面粘贴圆形PZT的相关机电阻抗（EMI）理论模型开发的。与现有方法相比，所提出的DCMI方法具有计算简单和放大信号的优点。将提取的DCMI信号与均方根偏差（RMSD）指标相结合，能够更有效地量化健康状况与信号变化之间的相关性。为了验证所提出的DCMI方法的有效性，对铝板和机身的一部分进行了详细实验。实验结果充分表明，所提出的通用DCMI方法在用于评估金属结构（包括由金属基纳米材料制成的结构）的健康状况时，比原始信号具有更好的灵敏度。
