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Capacitance-based nondestructive flaw evaluation (NDE), electric permittivity, piezoelectricity (capacitance-based stress/strain self-sensing) and piezoresistivity (resistance-based stress/strain self-sensing) of carbon-carbon composite (C/C, density 1.5 g/cm³, PAN-based carbon fiber) are unprecedentedly reported. The in-plane capacitance measured using coplanar electrodes decreases monotonically with increasing cumulative artificially inflicted damage (1–62 blind/through holes, diameter 1.00 mm), indicating NDE feasibility. The in-plane relative permittivity is 1.1 × 10⁴ (2 kHz); the in-plane DC resistivity is 2.4 × 10⁻³ Ω .cm. These values are similar to those previously reported for PAN-based carbon fiber. The permittivity increases reversibly by up to 16% with increasing elastic tensile strain (up to 0.0081%). However, the contribution of the stress-dependent permittivity to the piezoelectric effect is …