ABSTRACT
This chapter focuses on the fusion of multifrequency eddy current and pulsed eddy current data for the detection and quantification of hidden corrosion on aircraft structures. It explains what the fusion algorithms contribute to the corrosion quantification compared with the traditional calibration method and what is the most appropriate combination of nondestructive inspection data for characterizing the corrosion located at different layers in the multilayer aircraft fuselage joint example. The design of transport aircraft is relatively mature, and there are common elements across many manufacturers and models. The outer shell of the fuselage is generally built up from circumferential and longitudinal stringers, analogous to a skeleton, and aluminum skins are fastened to these stringers. The effects of corrosion on structural integrity are evaluated by a number of corrosion metrics. A straightforward way to quantify the inspection results is through the calibration process. The calibration specimen is prepared and inspected with the same experimental setup.
