Zhu Jianjian, Qing Xinlin, Liu Qijian, Liu Xiao, Wang Yishou
School of Aerospace Engineering, Xiamen University, Xiamen 361002, China.
Materials (Basel). 2019 Oct 4;12(19):3241. doi: 10.3390/ma12193241.
The single-lap joint of fiber-reinforced composites is a common structure in the field of structure repair, which has excellent mechanical properties. To study and monitor its quasi-static response behavior under external load, two methodologies called effective structural mechanical impedance (ESMI) and reduced-ESMI (R-ESMI) are presented in this article. A two-dimensional electromechanical impedance (EMI) model for a surface-bonded square piezoelectric transducer (PZT) is adopted to extract more sensitive signatures from the measured raw signatures. There are two major advantages of the monitoring scheme based on ESMI and R-ESMI signatures: (1) excellent monitoring results with less signatures to process, (2) the ability to monitor the quasi-static behavior of a single-lap joint with previously ignored susceptance signatures. Combining the extracted ESMI signatures with the index of root-mean-square deviation, the quasi-static behavior of single-lap joints can be effectively quantified. To test the effectiveness of ESMI methodology, verifying experiments were conducted. The experimental results convincingly demonstrated that the presented ESMI and R-ESMI methodologies have good feasibility in monitoring the quasi-static behavior of a fiber-reinforced composite single-lap joint. The proposed method has potential application in the field of structural health monitoring (SHM).
纤维增强复合材料的单搭接接头是结构修复领域中一种常见的结构，具有优异的力学性能。为了研究和监测其在外部载荷下的准静态响应行为，本文提出了两种方法，即有效结构机械阻抗（ESMI）和简化ESMI（R-ESMI）。采用表面粘贴方形压电换能器（PZT）的二维机电阻抗（EMI）模型，从测量的原始信号中提取更敏感的特征。基于ESMI和R-ESMI特征的监测方案有两个主要优点：（1）以较少的待处理信号获得优异的监测结果；（2）能够利用先前被忽略的电纳特征监测单搭接接头的准静态行为。将提取的ESMI特征与均方根偏差指标相结合，可以有效地量化单搭接接头的准静态行为。为了测试ESMI方法的有效性，进行了验证实验。实验结果令人信服地表明，所提出的ESMI和R-ESMI方法在监测纤维增强复合材料单搭接接头的准静态行为方面具有良好的可行性。该方法在结构健康监测（SHM）领域具有潜在的应用价值。
