Optimization of a Wide-Field Eddy Current Probe Using a Boundary Element Method Based Model

Abstract

Eddy current (EC) methods are widely used in the NDE inspection of critical aircraft engine components. Assessment of these components is particularly challenging due to the use of low conductivity materials and small flaw sizes, driven by high performance designs. Diverse EC probe designs have been produced over the years to maximize defect sensitivity, depending on the flaw characteristics and material type and condition. Traditionally, the performance of an eddy current probe design is evaluated by fabricating numerous prototype probes and performing scans in the desired test condition. Clearly this approach is both time-consuming and expensive. In particular, the EC probe has to be reconstructed each time the probe design is changed, and one design cycle may require a number of iterations before satisfactory performance is achieved. Moreover, due to the inexact science of probe fabrication, the performance of small design changes may be disguised by changes in manufacturing process variables.