Semi-analytical simulation of eddy current testing inspections by means of convergent Born series

Background Simulation of eddy current testing applications plays an important role in the design of inspection methods, in the signals interpretation to characterize flaws and as a support to the qualification process of inspection procedures. Objective Current efforts in modelling aim at proposing fast models able to address materials complexity such as nonlinearities. This work presents an approach consisting in solving the problem quickly using a iterative approach. Methods An application of Born series is proposed to accelerate the simulation of eddy current testing inspections. Fast eddy current testing (ECT) models typically exploit some symmetry of the piece proper0ty, as near field sensors are sensitive to local areas only of the piece under test, which can be considered symmetric. However, the presence of a 3D flaw breaks, most of the time, such symmetry. The use of Born series is a way to consider 3D flaws with an optimized solver exploiting the piece geometrical symmetry. Results Convergence issues of the series, which can limit the method applicability, are presented and overcome with illustration on a simplified application case. Conclusions The principle of the method, as well as a strategy to ensure convergence, have been demonstrated. The perspective of this work is the extension of the proposed approach to a 3D solver and the introduction of non-linear behaviour of the material under test.