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为了解利用压电阻抗方法识别钢管裂纹损伤的可行性,设计和制作钢管试验构件,通过机械加工方法模拟钢管裂纹产生和发展过程.利用压电阻抗方法对钢管裂纹损伤进行识别实验,实测各种损伤深度时压电陶瓷的PZT阻抗谱曲线,根据实验数据提取均方根差和协方差2个统计特征指标,分析裂纹损伤程度与统计特征指标之间的规律.试验结果表明,随着裂纹损伤程度加剧,PZT导纳频谱曲线明显向左偏移,峰值频率下降;阻抗谱曲线在高频段变化更明显,频率越高对初始损伤越敏感;均方根差和协方差等统计特征指标能有效判断钢管裂纹损伤状况.
In order to understand the feasibility of using piezoelectric impedance method to identify the damage of steel pipe, the experimental components of steel pipe were designed and fabricated, and the generation and development of steel pipe crack were simulated by mechanical processing method.The identification experiment of steel pipe crack damage was carried out by piezoelectric impedance method, The PZT impedance spectra of the piezoelectric ceramics at the depth of damage were extracted, and two statistical characteristic indexes, root mean square error and covariance, were extracted from the experimental data to analyze the regularity between the degree of the crack damage and the statistical characteristic index.The experimental results showed that with the crack damage The PZT admittance spectrum curve shifted to the left and the peak frequency decreased. The impedance spectrum curve changed more obviously in the high frequency range. The higher the frequency, the more sensitive to the initial damage. The statistical characteristic indexes such as RMSE and covariance were effective Judge the steel crack damage.