Self-sensing of damage in carbon fiber polymer-matrix composite cylinder by electrical resistance measurement

Self-sensing of damage, as attained by electrical resistance measurement, was found to be effective in a carbon fiber polymer-matrix composite cylinder made by filament winding. Resistance was measured in the axial, radial, oblique, and circumferential directions by using circumferential or axial electrical contacts on the outer and/or inner surfaces of the cylinder. Minor damage upon drop impact at 10J or below caused the radial resistance to decrease irreversibly, whereas major damage upon drop impact above ≈10J caused the radial, oblique, and axial resistances to increase irreversibly. The circumferential resistance ratio (ratio of the circumferential resistance of a damaged area to that away from the damaged area) was most sensitive, increasing monotonically with impact energy > 1.4J.