A fast 3D semi-analytical model for simulating flaw responses provided by a magnetic flux leakage NDT system inspecting ferromagnetic pipes

A. Trillon (1) , F. Deneuville (1) , Denis Prémel (2) , S. Djafa (2) , Lionel Pichon (3)

1 SETVAL - Centre de Recherche VALLOUREC
2 DISC (CEA, LIST) - Département Imagerie et Simulation pour le Contrôle (CEA, LIST)
3 LGEP - Laboratoire de génie électrique de Paris

This communication presents a semi-analytical model based on BEM formalism for computing MFL flaw responses. MFL 2D configurations have been already simulated in the linear case taking into account the complex shape of the magnetizing circuit surrounding the pipe to be inspected. In this paper, the 3D problem is considered, but, in a first step, in order to be able to solve the non-linear problem, we assume that each ferromagnetic part can be divided in a finite number of polyhedral cells of complex shapes, assuming that the relative magnetic permeability is constant inside each cell. The nonlinear magnetosattic problem may be tackled as a finite number of successive 3D linear problems: the unknowns of the problem being the values of the surface magnetic charge density, in this case, the scalar potential of single layer charge on all the facets of each cell. By assuming that the unknowns are piecewise constant on all the facets of each cell, the kernels derived from integral equations can be analytically evaluated. The implemented semi-analytical model reveals itself to be very effective. Some simulated data are presented for some specific configurations before solving truly NDT MFL configurations.

Mots clés: Eddy current testing; modeling; Nondestructive testing

Domaines: Physique [physics]

A. Trillon, F. Deneuville, Denis Prémel, S. Djafa, Lionel Pichon. A fast 3D semi-analytical model for simulating flaw responses provided by a magnetic flux leakage NDT system inspecting ferromagnetic pipes. QNDE 2013 - 40TH Annual Review of Progress in Quantitative Nondestructive Evaluation, Jul 2013, Baltimore, MD, United States. pp.1421-1427, ⟨10.1063/1.4864988⟩. ⟨cea-01820688⟩