Eddy Current Modeling in Composite Materials

The production of carbon ¯ber reinforced polymers, which are widely used both
in civil and military applications, is an elaborate process un-free from faults and problems.
Problems during the manufacturing, such as plies' overlapping, can cause °aws in the resulting
material, this way compromising its integrity. Compared with metallic materials, carbon epoxy
composites show a number of advantages: Higher tensile strength, lower density and coe±cient of
thermal expansion, absence of fatigue state related phenomena, possible manufacturing of large
layered structures. Within this framework, this work aims to propose a design of ferrite core
probe for eddy current non destructive evaluation, in order to investigate the presence of defects
in carbon ¯ber epoxy composite materials. The e®ect of the ferrite core is analyzed in order
to focus magnetic °ux density on the investigated specimen. Eddy currents generated by high
speed ferrite core probe movement were investigated by using numerical simulation. Particularly,
a Finite Element Approach has been exploited in order to characterize the transducer to specially
emphasize the presence of defects in a multi-layer carbon ¯ber epoxy structure.