Optimizing the Inversion Protocol to Determine the Geometry of Vertical Cracks from Lock-in Vibrothermography
Optimizing the Inversion Protocol to Determine the Geometry of Vertical Cracks from Lock-in Vibrothermography
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DOI：
10.1007/s10921-016-0381-5
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发表时间：
2017-03-01
影响因子：
2.8
通讯作者：
Salazar, A.
中科院分区：
文献类型：
--
作者：
Castelo, A.;Mendioroz, A.;Salazar, A.
我们使用低强度锁定振动热成像来表征任何形状的垂直裂纹。从振动热成像数据中寻找裂纹的几何形状和位置的反问题是不适定的，这使得有必要稳定反演算法。在以前的工作中，我们开发了一个稳定的反演程序，能够从锁定振动热成像数据的矩形形状的垂直裂纹的特征。在这项工作中，我们扩展的方法来表征垂直裂纹的任意形状。为此，首先，我们改进的稳定算法，以获得准确的裂纹形状重建。然后，我们在进入算法之前优化处理数据所遵循的协议。为了验证新的程序，我们反演，合成数据与添加均匀噪声和实验数据的样本含有校准的人工裂纹的不同形状。结果表明，非常准确的重建获得了浅裂纹。随着裂纹深度的增加，尽管裂纹的形状是圆形的并且其面积被稍微高估，但是深度被精确地获得。
We use low intensity lock-in vibrothermography to characterize vertical cracks of any shape. The inverse problem, consisting in finding the geometry and location of the crack from vibrothermography data is ill-posed, which makes it necessary to stabilize the inversion algorithm. In previous works, we developed a stabilized inversion procedure that was able to characterize vertical cracks of rectangular shape from lock-in vibrothermography data. In this work, we extend the method to characterize vertical cracks of arbitrary shape. For this purpose, first we improve the stabilization algorithm to obtain accurate crack shape reconstructions. Then, we optimize the protocol followed to handle data before entering the algorithm. To validate the new procedure we invert both, synthetic data with added uniform noise and experimental data on samples containing calibrated artificial cracks of different shapes. The results show that very accurate reconstructions are obtained for shallow cracks. As the depth of the crack increases, the depth is precisely obtained although the shape of the crack is rounded and its area is slightly overestimated.