Mechanical stress identification method in anisotropic ferromagnetic materials using eddy current testing

This work presents a numerical model describing the effect of mechanical stress on the impedance signal of an eddy current sensor for an application in non-destructive testing. The anisotropy of the magneto-elastic behaviour of the material (API-5L X52) is taken into account through a simplified multi-scale approach. The constitutive behaviour is implemented into a finite element model to solve the magneto-dynamic problem. The modelling results are compared with measurements performed on samples extracted along two orthogonal directions of a pipeline.