TITLE:
Self-Sensing Curved Micro-Strip Line Method for Damage Detection of CFRP Composites
AUTHORS:
Akira Todoroki, Kazuhiro Yamada, Yoshihiro Mizutani, Yoshiro Suzuki, Ryosuke Matsuzaki, Hiroyasu Fujita
KEYWORDS:
Carbon Fibre, Composite, Laminates, Electric Resistance, Fiber Breakage, Time Domain Reflectometry, Self-Sensing
JOURNAL NAME:
Open Journal of Composite Materials,
Vol.4 No.3,
July
7,
2014
ABSTRACT: 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.