Reflectometric systems for in-situ diagnosis on carbon fibre-reinforced composite structures

In this work, the feasibility of the adoption of microwave reflectometry (MWR) for diagnosing the status of structures made of composite materials is investigated. In particular, two different "sensing structures", based on microstrip and coplanar configurations, are considered. The analysis focused on carbon fibre-reinforced composite structures, which are extensively used in aircraft industry. It goes without saying that, despite the widespread diffusion of this class of materials in the aircraft industry, there are two crucial requirements for which effective diagnostic methods are far from being adequately implemented. First, it is necessary to detect the possible presence of gaps between structural components after they are assembled. Secondly, there is the need to periodically control (during the service life of the aircraft) the amount of moisture that may have been absorbed by the composite structure. To this purpose, the present work intends to pave the way for future practical implementation of MWR based systems for these diagnostic requirements.