A Model Assisted Probability of Detection Approach for Ecndt of Hidden Defect in Aircraft Structures

Abstract

In a probabilistic approach, the performance of the control is characterized by statistical indicators such as the Probability of Detection (PoD) which describes the probability of detecting a defect of a given size knowing that it is present in the inspected structure. In this paper, an experimental analysis and simulation using FEM of the eddy current testing on three-dimensional riveted structure is performed on small fatigue cracks to identify and quantify probability of detection curves. The PoD curves are plotted in terms of characteristic dimensions of the defect (depth, length, orientation, etc.) and are dependent on a number of factors including material, geometry, defect type, operator, and environmental effects.

An Integro-Differential Approach for Eddy Currents Computation in Structures Having Heterogeneous Dimensions

“…When using electromagnetic nondestructive evaluation (NDE) [15], the measurement signal received by the probe coil is determined by an error related to the operating parameters being inspected. Invariant pattern recognition techniques have been investigated to make NDE signals insensitive to operational fluctuations and to store or restore crack information.…”

“…The succeeded computing is the fastest without losses in physical information. This particularity is very important to enable a broad exploratory investigation of the testing and design space [11,15]. The differential approach, such as FEM method, allows modeling of complex devices, but this kind of methods is computationally expensive especially with structures containing a large number of conductors and having heterogeneous dimensions.…”

Efficient Model Assisted Probability of Detection Estimations in Eddy Current NDT with ACA-SVD Based Forward Solver

“…This approach is the model assisted PoD (MAPoD) which mitigates the extensive amount of empirical data required in PoD study [ 13 ]. A wide range of physics-based numerical simulation models for eddy current NDT systems have been proposed [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. The finite element method (FEM), which solves the differential equations, draws extensive attentions in MAPoD study because it is easier to implement than the boundary element method (BEM) or volume element method (VEM), which solve the integral equations [ 14 , 15 , 16 , 17 ].…”

“…A wide range of physics-based numerical simulation models for eddy current NDT systems have been proposed [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. The finite element method (FEM), which solves the differential equations, draws extensive attentions in MAPoD study because it is easier to implement than the boundary element method (BEM) or volume element method (VEM), which solve the integral equations [ 14 , 15 , 16 , 17 ]. However, it discretizes the whole solution domain with volume meshes which need large computational resources in both FEM and VEM [ 23 ].…”