Numerical modeling of moving probe effects for electromagnetic nondestructive evaluation

In view of the complex geometries involved in nondestructive evaluation (NDE) applications, a transient analysis for moving probe effects is performed. The time-step method used successfully reproduces the steady-state upwinding results by introducing a time-dependent artificial reluctivity term. The support plate signal of the variable reluctance probe obtained at the probe velocity of 5 m/s is compared with that of 0 m/s, i.e., the magnetostatic result. Due to the time dependence of the artificial reluctivity term, numerical dissipation is less than that of time stepping with upwinding. The matrix becomes symmetric in this formulation, which has many beneficial aspects compared to the upwinding nonsymmetric matrix