A fast forward solution with a boundary element method for eddy current nondestructive testing

Eddy current non-destructive testing is used to determine position and size of cracks or other defects in conducting materials. The presence of a crack normal to the excited eddy currents distorts the magnetic field; so for the identification of defects a very accurate and fast 3D-computation of the magnetic field is necessary. A computation scheme for 3D quasistatic electromagnetic fields by means of the Boundary Element Method is presented. Although the use of constant field approximations on boundary elements is the easiest way, it often provides an insufficient accuracy. This can be overcome by higher order approximation schemes. The numerical results are compared against some analytically solvable arrangements.