Spatially resolved self-sensing of strain and damage in carbon fiber cement

Spatially resolved self-sensing of strain and damage has been shown in carbon fiber cement under flexure by three-point bending. This involves measurement of the one-dimensional distribution of the DC electrical resistance by the use of surface electrical contacts on the bottom (tension) and top (compression) surfaces. For a span of 290 mm, a spatial resolution of 5 mm has been attained. The bottom surface resistance, which increases reversibly with strain and increases irreversibly with damage, is a more effective indicator of strain and damage (in combination) than the top surface resistance, the oblique resistance or the through-thickness resistance for spatially resolved self-sensing. For sensing without spatial resolution, the oblique resistance is the most effective indicator. For sensing with distinction between strain and damage, the top surface resistance is the most effective indicator.