Author(s)

Akira Todoroki, Kazuhiro Yamada, Yoshihiro Mizutani, Yoshiro Suzuki, Ryosuke Matsuzaki, Hiroyasu Fujita

Aerospace Company, Fuji Heavy Industry, Tochigi, Japan.
Department of Mechanical Engineering, Tokyo University of Science, Chiba, Japan.
Department of Mechanical Sciences of Engineering, Tokyo Institute of Technology, Tokyo, Japan.
Tokyo Institute of Technology, Tokyo, Japan.

A self-sensing Time Domain Reflectometry (TDR) method for Carbon Fibre Reinforced Polymer (CFRP) laminates has been propped in the present study: carbon fibres are used as sensors using a transmission line. Authors have published research articles of the self-sensing TDR method. The self-sensing TDR method reduces number of required electrodes for damage detections although the sensitivity of detection is sacrificed. A micro-strip line (MSL) method is adopted to obtain impedance matching with a coaxial cable and successfully detected damage in a CFRP laminate in the previous study. In the present study, a long curved MSL is experimentally investigated as an impedance-matched transmission line for detection of damage of a CFRP laminate in wider area. Fibre breakage is simulated as a hole made by drilling. As a CFRP laminate has strongly orthotropic electric conductance and the electric properties of a CFRP laminate at the high frequency are not clarified, the effect of the orthotropic conductance at the curved transmission line is experimentally investigated. As a result, the effect of orthotropic conductance at the curved strip line is shown to be negligible, and fiber breakage that locates closed to the copper strip line can be detected by the self-sensing curved MSL method. It is, however, difficult to detect damage far from the copper strip line.

Carbon Fibre, Composite, Laminates, Electric Resistance, Fiber Breakage, Time Domain Reflectometry, Self-Sensing

Todoroki, A. , Yamada, K. , Mizutani, Y. , Suzuki, Y. , Matsuzaki, R. and Fujita, H. (2014) Self-Sensing Curved Micro-Strip Line Method for Damage Detection of CFRP Composites. Open Journal of Composite Materials, 4, 131-139. doi: 10.4236/ojcm.2014.43015.