Changes in electric resistance of cracked copper-coated, pitch-based carbon fibres for structural health monitoring in a glider wing

Research output: Contribution to journalConference articleContributedpeer-review


Structural health monitoring based on detecting strain enables further exploitation of the lightweight potential of aircraft structures. Since carbon fibres (CF) can be easily integrated into aircraft structures made of fibre-reinforced plastics (FRP), their use in sensor applications has become subject of research. One of many novel approaches is the use of cracked CF for strain detection. During loading and unloading, the fibre cracks are opening and closing respectively, resulting in substantial changes in the electric resistance of the CF. The high dependence of the electric resistance on the mechanical strain enables spatially resolved strain sensing along the CF based on the electric time domain reflectometry (ETDR) principle. However, due to high inhomogeneity of the used pitch-based CF and the resulting electric properties, the ETDR-signal is degraded largely by impedance mismatch along the transmission line, which limits the measuring length of a spatially resolved sensor. In this contribution, a concept for a spatially resolved CF-based strain sensor is described, outlining the challenges that need to be addressed. One approach for the extension of the measuring length is lowering the base resistivity of the used CF, which is discussed in detail. In order to achieve a low base resistivity while maintaining the characteristic of opening and closing fibre cracks, copper-coated CF are investigated. The copper-coated pitch-based CF are integrated into test specimens consisting of a composite material and are subjected to tensile loading. Simultaneously to the deflection, the electrical resistance is measured. Consequently, the sensitivity to strain of the CF is determined and discussed.


Original languageEnglish
Article number012066
Number of pages8
JournalJournal of Physics: Conference Series
Issue number1
Publication statusPublished - 28 Jun 2023


Title12th EASN International Conference on "Innovation in Aviation & Space for opening New Horizons"
Abbreviated titleEASN 2022
Conference number12
Duration18 - 21 October 2022
Degree of recognitionInternational event
LocationUniversitat Politècnica de Catalunya

External IDs

Mendeley 6204362d-fcf0-3ddf-8279-aa0540497099
ORCID /0000-0003-2834-8933/work/142238448
ORCID /0000-0003-1385-1528/work/142240121
ORCID /0000-0002-8854-7726/work/142242120
Scopus 85169675122
WOS 001052253100066
ORCID /0000-0002-0110-3066/work/156812784