Relationship between electrical resistance and strain of carbon fibers upon loading

The changes in electrical resistance of carbon fibers during a tensile elongation were investigated to understand the electromechanical mechanism in carbon fibers. The fractional electrical resistance of carbon fibers initially increased slightly with increasing elongation, however, increased abruptly beyond a certain strain where the rupture of fibers began to increase. Contribution to this change in electrical resistance was analyzed in terms of dimensional change of fibers, number of ruptured fibers, and degree of fiber contacts. The effect of the number of ruptured fibers was the most dominant, whereas the effect of the dimensional change of carbon fibers due to elongation was relatively small. The degree of contacts between fibers affected the change in electrical resistance dominantly at the large elongation. The residual electrical resistance appeared upon removal of the applied strain and increased with increasing elongation, regardless of the static and dynamic loading. Consequently, the smart characteristics of carbon fibers due to the existence of the residual electrical resistance are primarily ascribed to the number of ruptured fibers and contacts between fibers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2082–2087, 2000

[1]  Y. Benveniste.  On the micromechanics of fibrous piezoelectric composites , 1994 .

[2]  Jr. W.B. Spillman,et al.  Sensing and processing for smart structures , 1996, Proc. IEEE.

[3]  Karl Schulte,et al.  Load and failure analyses of CFRP laminates by means of electrical resistivity measurements , 1989 .

[4]  D.D.L. Chung,et al.  Continuous carbon fibre epoxy-matrix composite as a sensor of its own strain , 1996 .

[5]  J. Ferry.  Viscoelastic properties of polymers , 1961 .

[6]  A. R. Bunsell,et al.  Acoustic emission during cyclic loading of carbon-fibre-reinforced plastics , 1975 .

[7]  J. Cho,et al.  Electrically conducting high-strength aramid composite fibres prepared by vapour-phase polymerization of pyrrole , 1997 .

[8]  Xiaojun Wang,et al.  An electromechanical study of the transverse behavior of carbon fiber polymer-matrix composite , 1997 .

[9]  Hiroaki Yanagida,et al.  Preventing Fatal Fractures in Carbon‐Fiber–Glass‐Fiber‐Reinforced Plastic Composites by Monitoring Change in Electrical Resistance , 1993 .

[10]  Izabella Krucińska,et al.  Direct measurement of the axial poisson's ratio of single carbon fibres , 1991 .

[11]  C. Owston,et al.  Electrical Resistance of Single Carbon Fibres , 1969, Nature.

[12]  Xiaojun Wang,et al.  Electromechanical study of carbon fiber composites , 1998 .

[13]  N. Hagood,et al.  Anisotropic Actuation with Piezoelectric Fiber Composites , 1995 .

[14]  A. Loos,et al.  Production of controlled networks and morphologies in toughened thermosetting resins using real-time, in situ cure monitoring , 1996 .

[15]  D.D.L. Chung,et al.  Carbon‐Fiber‐Reinforced Concrete as an Intrinsically Smart Concrete for Damage Assessment during Dynamic Loading , 1995 .