An Experimental Study on Applicability of Passive Electric Potential CT Method to Crack Identification
An Experimental Study on Applicability of Passive Electric Potential CT Method to Crack Identification
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DOI：
10.1299/jsmea.47.419
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发表时间：
2004-07
期刊：
影响因子：
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通讯作者：
D. Shiozawa;S. Kubo;T. Sakagami
中科院分区：
文献类型：
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作者：
D. Shiozawa;S. Kubo;T. Sakagami
本文介绍了无源电位CT（计算机层析成像）方法的适用性，它不需要施加电流进行损伤检测。该方法将压电薄膜粘贴在结构表面作为传感器。当结构受到外部载荷时，压电膜上的电势值由于结构上的应变分布而改变。裂纹体的应变分布在压电薄膜上引起特征电势分布。因此，被动观察压电薄膜上的电势值可以用于缺陷识别。将基于最小残差法的逆方法应用于由电位分布识别裂纹。在这种逆方法中，残差的平方和之间的测量的电位分布和通过使用有限元方法计算的。该方法可用于开发具有缺陷自监测功能的智能结构。采用接触式和非接触式两种方法测量压电薄膜上的电势。利用所测得的电位分布，用本反演方法识别裂纹。结果表明，被动电位CT法可以定量地识别裂纹的位置、大小和深度。
This paper describes the applicability of passive electric potential CT (computed tomography) method which does not require electric current application for damage detection. In this method, piezoelectric film is glued on the surface of structures as a sensor. Electric potential values on the piezoelectric film change due to the strain distribution on the structure, when the structure is subjected to external load. The strain distribution of the cracked body induces a characteristic electric potential distribution on the piezoelectric film. Therefore passively observed electric potential values on piezoelectric film can be used for the defect identification. An inverse method based on the least residual method was applied to the crack identification from the electric potential distribution. In this inverse method, square sum of residuals is evaluated between the measured electric potential distributions and those computed by using the finite element method. This method may be applied to develop an intelligent structure with a function of self-monitoring of flaws and defects. The electric potential on piezoelectric film was measured by the contact type and the non-contact type methods. The measured electric potential distribution was used to identify a crack by using the present inverse method. It was found that the location, size and depth of the crack can be quantitatively identified by the passive electric potential CT method.