Techniques
that monitor the change in the electrical properties of materials are promising
for both non-destructive testing and structural health monitoring of
carbon-fiber-reinforced polymers (CFRPs). However, achieving reliable
monitoring using these techniques requires an in-depth understanding of the
impedance response of these materials when subjected to an alternating
electrical excitation, information that is only partially available in the
literature. In this work, we investigate the electrical impedance spectroscopy
response at various frequencies of laminates chosen to be representative of
classical layups employed in composite structures. We clarify the relationship
between the frequency of the electrical current, the conductivity of the
surface ply and the probing depth for different CFRP configurations for more
efficient electrical signal-based inspections. We also investigate the effect
of the amplitude of the input signal.
