基于高频压电阻抗信号的钢制薄板损伤识别研究

为了利用机电阻抗技术(EMI)来实现结构的损伤识别,并考虑外部温度环境的影响。通过获取的压电阻抗信号并经过压电阻抗分析技术得到了结构的高频振动信息,从而达到识别结构损伤的目的。利用该技术对钢制薄板进行了损伤识别的试验研究,并采用电阻抗实部的协方差(Covariance)作为损伤指标定量地识别了损伤的严重程度和损伤的扩展。试验研究表明,利用机电阻抗技术能够很好地识别结构的损伤。进一步的研究还表明,该技术不受外部温度环境的影响,可以实现结构损伤的实时在线监测。

DAMAGE IDENTIFICATION OF STEEL SHEETS BASED ON HIGH-FREQUENCY PIEZOELECTRIC SIGNALS

Electro-mechanical impedance(EMI) technique can be used to detect damages to structures using high electro-mechanical impedance signals.The piezoelectric impedance signals were then measured from the PZT patches by an impedance(or network) analyzer and the structural damages can be detected through proper analysis.Experimental study was implemented in this paper to illustrate the effectiveness of this technology and a covariance was employed as a damage index to assess the damage severity and propagation quantitatively.The experimental investigation showed that EMI technique was an effective health monitoring method and could be used in the field of real-time on-line incipient damage detection,even with the presence of significant temperature variation.