Sensitivity Analysis of Magneto-Optic Imaging

Magneto-Optic Imaging (MOI) is a relatively new nondestructive evaluation modality that provides real time images of surface and subsurface features. In this technique, flux leakage maps associated with applied currents are recorded and monitored to locate material defects. Various factors affect the sensitivity of nondestructive evaluation using MOI including structure geometry, instrumentation parameters, and flaw characteristics. Computational modeling is presented in this research to characterize the sensitivity of MOI to material flaws. Three-dimensional finite element formulation is invoked to study the interaction of applied current and specimen under test. Results are shown of performance of MOI systems in detecting hidden flaws in pipeline configuration. Analysis considers a range of excitation source parameters and specimen defect characteristics. Accurate sensitivity analysis would help optimize MOI system design and promote its use in NDE applications in inspecting pipelines.