• Onggar, T.
• Hund, R.-D.
• Cherif, Chokri
• Weißenborn, O.
• Geller, S.
• Modler, Nils
• Häntzsche, Eric Martin
• Nocke, Andreas

Abstract

For the purpose of structural health (SHM) and even load monitoring, the conceptual design and approaches for structural integration techniques of suitable fibre-based sensor components for composite components are still a challenge for both engineering and materials science. In this contribution, the characteristic of yarns that have intrinsically conductivity, e.g. carbon fibre (CF), and their suitability to act as in-situ strain sensors are described. The objective of the based research project is the real-time in-situ sensing of global stresses and the detection of resulted local microscopic damages due micro-cracks and delamination in the load bearing layers of carbon fibre reinforced plastic (CFRP) components. Sensor material similar to the particular CFRP and its mechanical behaviour has been chosen, in this case a CF roving with total titer of 67 tex. The measurement principle bases on usage of the piezo-resistive effect for the usage as in-situ strain sensors, means that every mechanical straining of the roving's filaments causes a correlative change of the measureable resistance. In the next step, suitable fibre-based dielectric jackets have been preferably applied by brasiding technology, granting sufficient isolation to avoid short-circuits between the conductive sensor itself or between the sensor and intrinsically conductive CFRP respectively. Performing load test of CFRP specimens with suchlike functionalised integrated sensor yarns, the sensor's performance to detect global strain, means the accumulated strain along the integration length of the sensor yarn, has been evaluated.

Topics

• impedance spectroscopy
• polymer
• Carbon
• crack
• composite