压电阻抗技术用于螺栓松紧健康诊断

实验研究了利用压电片进行结构微小损伤的健康诊断，以螺栓松动为例，在螺栓附近粘贴压电片，对压电片实施激励，实验分析螺栓松动情况下压电片的特性变化。结果表明，螺栓松动引起的微小损伤，在低频电压激励下引起压电片导率变化不显著，但是在高频下（大于50kHz)，不同的作用频率范围下，压电片导率都有明显改变，因此，高频作用下压电片导率的变化可以作为结构健康诊断的一个标尺。

Research on Piezoelectric Impedance Technology for Bolt Health Monitoring

The purpose of this paper is to demonstrate experimentally the feasibility of structural incipient health monitoring through the admittance measurement of piezoelectric patches bonded to the structure. The incipient damage, loose of a bolt in a beam was given as an example. In low frequencies domain and high frequencies domain, the piezoelectric admittance was measured when the bolt was loose. The results show the loose of the bolt causes the obvious variations of the admittance in high frequency domain. But in low frequency domain, the change of the piezoelectric admittance is only limited. Thus, the change of piezoelectric admittance can give a scale for structural health monitoring in high frequency domain.