Reliability Assessment for Nano Engineered Fatigue Crack Sensor.

Abstract

The present research presents a novel approach for monitoring fatigue crack growth. The sensor itself is a sheet of Carbon Nanotube (CNT) sandwiched between a pair of electrically insulating layers. Any crack growth below the sensor would disrupt the CNT electrical network, therefore increasing the network resistance. Using orthogonal parallel pairs of electrodes, one would be able to not only measure extent of a crack, but also deduce the orientation based on relative changes seen by each pair; a flaw growing towards an electrode would have a small effect, while growing parallel to an electrode pair would offer a significant measured change. Analytical results are presented along with experimental data for calibrated simulated crack growth in addition to actual fatigue crack growth in aluminum specimens. The eventual goal for the program is to couple this sensor with RFID technology to provide a passive and connector-less assessment of fatigue crack growth