Integration of multiple response signals into the probability of detection modelling in eddy current NDE of flaws
Integration of multiple response signals into the probability of detection modelling in eddy current NDE of flaws
复制标题
DOI：
10.1016/j.ndteint.2020.102401
复制
发表时间：
2021-01-09
影响因子：
4.2
通讯作者：
Ribeiro, A. L.
中科院分区：
文献类型：
--
作者：
Baskaran, Prashanth;Pasadas, D. J.;Ribeiro, A. L.
在这项工作中，提出了一种新的方法建模的检测概率（PoD）的缺陷参数（缺陷长度）的情况下，多个相关的缺陷响应信号。通过边界元法辅助PoD建模，以计算所需的缺陷特征，即两个不同频率下线圈阻抗的最大变化。使用LCR计进行实验以验证边界元模型的预测。模拟是在有限厚度的铝-1050板上进行的，该板具有窄开口表面缺陷。这些特征针对不同的缺陷长度进行计算，并与二元高斯分布拟合，从而避免了异方差问题。在已知信号阈值的情况下，可以从高斯密度计算缺陷长度的PoD。得到的离散的PoD，然后回归广义逻辑函数（GLF），以获得一个连续的函数的缺陷长度的PoD。GLF的参数估计通过Levenberg-Marquardt算法通过非线性最小二乘最小化。
A new method of modelling the probability of detection (PoD) of a flaw parameter (flaw length) for the case of multiple correlated flaw response signals is proposed in this work. The PoD modelling is assisted by boundary element method in order to compute the required flaw features, the maximum change in the impedance of a coil, at two different frequencies. Experiments were performed using a LCR meter to verify the predictions of the boundary element model. The modelling was performed on a finite thickness aluminum-1050 plate with a narrow opening surface flaw. The features were computed for various flaw lengths and fit with a bi-variate Gaussian distribution, thus evading the problem of heteroscedasticity. On knowing the signal thresholds, the PoD of a flaw length can be computed from the Gaussian density. The obtained discrete PoD is then regressed by a generalized logistic function (GLF) in order to attain a continuous function for the PoD of the flaw length. The parameters of the GLF are estimated via non-linear least squares minimization by Levenberg-Marquardt algorithm.