Hardware implementation of electrical resistance tomography for damage detection of carbon fibre–reinforced polymer composites

Abstract

The growing use of carbon fibre–reinforced polymer materials in aerospace and industrial applications requires the deployment of appropriate tools for detecting the occurrence and development of damage as well as for monitoring the durability of conductive composite structures. Electrical resistance tomography is a promising method in this field, since many types of fibre composite defects cause changes in the spatial distribution of conductivity. In comparison with other methods in the field of structural health monitoring, electrical resistance tomography has, at first glance, modest requirements for sensors, and thus appears to be a useful instrument in this field. Most of the previously conducted experiments in this field relied on the stand-alone hardware thereby did not contribute to a technological readiness level of the electrical resistance tomography. The article describes an experiment conducted on a carbon fibre–reinforced polymer composite specimen in laboratory conditions nevertheless with minimum usage of stand-alone equipment. Attention is focused on the first steps in the development of hardware, namely on the instrumental amplifier with active shielding and the voltage controlled current source. Experimental verification of usability of these components along with observed common mode voltage error and dynamic range is useful for next development of more complicated device such as a multiplexer. Greater attention is also paid to the implementation of electrodes, as these are a key part. The main contributions of proposed work lie in the usability verification of the key hardware components with the help of basic image reconstruction of the real damage.