New discretisation scheme based on splines for volume integral method: Application to eddy current testing of tubes
Résumé
Purpose - A numerical model dedicated to external eddy current inspection of tubes has been developed using the volume integral method (VIM). The purpose of this paper is to suggest new discretization schemes based on non-uniform B-splines for the solution of the state equation with the method of moments (MoM). Design/methodology/approach - VIM is a semi-analytical approach providing fast and accurate results for the simulation of eddy current testing (ECT) of pieces with canonical geometries. The state equation derived with this formalism is solved using the Galerkin variant of the well-known MoM. Findings - This paper shows that an accuracy improvement is achieved in MoM by using B-splines with degree 1 or 2 as projection functions in MoM instead of pulse functions. Moreover, comparisons between simulation results show that, for all ECT configurations tested, the use of degree 1 B-splines is sufficient to get this improvement. Originality/value - The use of B-splines functions has already been proposed for MoM in the literature, but not in the framework of the Galerkin variant of MoM. This paper also shows quantitative comparisons between experiment and simulation as well as a study of the minimal degree required to get an accuracy improvement in MoM.