First report of capacitance-based self-sensing and in-plane electric permittivity of carbon fiber polymer-matrix composite

The in-plane capacitance of continuous carbon fiber polymer-matrix composite is sensitive to the damage. The figure show a comparison of the sensing characteristics for the perpendicular and parallel orientations of the fibers for all cases (i.e., all levels of damage). The capacitance C relative to the value Co for no damage vs. Case No. is shown. ●: Fibers being parallel to the line joining the two coplanar electrodes. ○: Fibers being perpendicular to the line joining the two coplanar electrodes.134