A New Imaging Approach to In Situ and Ex-Situ Inspections of Fibre Reinforced Composites by Magnetic Induction Tomography (MIT)

Fiber reinforced composites (FRP) for industrial applications face constantly increasing demands regarding efficiency, reliability and economy. Furthermore, it was shown that FRP’s with tailored reinforcements are superior to metallic or monolithic materials. However, a trustworthy description of load-specific failure behaviour and damage evolution of composite structures can hardly be given, because these processes are very complex and are still not entirely understood. Amongst other things, several research groups have shown that material damages like fiber fracture, delamination, matrix cracking or flaws can be discovered by analyzing the electrical properties of conducting composites, e.g. carbon fiber reinforced plastics (CFRP). Furthermore, it was shown that this method could be used for structural health monitoring or non-destructive testing (NDT) [8–12].Within this work, Magnetic Induction Tomography (MIT), which is a new imaging approach, is introduced into the topic of NDT of CFRP’s. This non-contacting imaging method gains the inner spatial distribution of conductivity of a specimen and depicts material inhomogeneity, like damages, in 2D or 3D images. Numerical and experimental investigations are presented and give a first impression of the performance of this technique. It is demonstrated that MIT is a promising approach for NDT and could be used for fabrication quality control of conductive FRP’s and could potentially be used as a health monitoring system using an integrated setup.