基于压电阻抗方法的油气管道裂纹损伤定量研究

PIEZOELECTRIC IMPEDANCE-BASED QUANTITATIVE STUDY ON OIL AND GAS PIPELINE CRACK DAMAGE

为了解基于压电阻抗方法识别管道裂纹损伤程度的可行性,通过人工切割方法模拟管道裂纹损伤,采用压电阻抗方法对管道裂纹损伤进行监测试验。实测各种损伤工况下压电片的阻抗信号,分析试验数据,提取均方根差(RMSD)作为损伤指标。基于RMSD损伤指标与损伤面积的变化规律,建立了管道损伤程度量化表征的数学模型。试验结果表明:当管道出现裂纹损伤后,PZT阻抗频谱曲线明显向左偏移,峰值对应频率下降;随着管道裂纹损伤程度不断加大,RMSD值逐渐增长,RMSD损伤指标能定性地判断管道损伤状况。所建立的数学模型在一定程度上实现了管道裂纹损伤的定量分析。

In order to understand the feasibility for identifying pipeline crack damage degrees using the impedance-based method, the crack damage on pipeline was simulated by artificial methods. A crack damage monitoring experiment was carried based on the piezoelectric impedance method. The PZT impedance signal of piezoelectric ceramic was measured in different damage conditions. Through analyzing the experimental data, root mean square deviation（RMSD） was obtained. According to the variation laws of the damage index and area, the quantifying mathematical model of pipeline damage degrees was established. The experimental results showed that the spectrum curve of PZT electrical impedance was significantly offset to the left, that the peak of frequency was dropped once damage appears, and that with the aggravation of crack damage degrees, damage index values increased, which showed that RMSD can deduce the damage condition. The quantitative assessment of pipeline crack damage can be realized by the established mathematical model in a certain extent.