Preliminary Experiment of CFRP Displacement Direct Measurement with Eddy Current Sensor

Abstract

Displacement and vibration can always be found during the applications of CFRP ( carbon fibe reforced polymer). So it’s quite meaningful to measure the displacement of CFRP directly. Eddy current sensor is a promising tool for this measurement. CFRP presents great heterogeneity and high anisotropy in electromagnetic properties. At the same time, it has been proved that CFRP has quite weak conductivity. All of these means great challenge to the use of eddy current sensor, as the sensitivity would be much lower compared with traditional material such as aluminum. Many experiments have been carried out on the experimental platform self-developed in laboratory. A simplified eddy current sensor with adjustable resonant circuits was designed. Two different kinds of CFRP were used as specimens. For purposes of comparison, an aluminum ingot sample was also tested. A number of experimental data and results have been achieved. It is shown that the sensitivity will be highly improved by adjusting the divider resistance and the actuation frequency.