Distributed sensory system of surface cracks monitoring based on electrical impedance tomography

Abstract

In this paper, we propose a method of distributed sensory systems designing for monitoring of surface cracks in highly loaded constructions based on electrical impedance tomography. A thin conductive film with contacts on the perimeter applied on the monitored surface is used as a crack sensor. Registration and monitoring of surface cracks using the developed modified method of electrical impedance tomography (EIT) are carried out. The proposed method differs from the traditional EIT method as it has considerably lower computational complexity with sufficient resolving power. This makes it possible to use the proposed EIT method for continuous rapid monitoring of surface cracks during the operation of a controlled construction in real-time mode. The main stages of the proposed modified EIT method, a block diagram of the crack image reconstruction algorithm and a method for processing the crack images, which provide the possibility for adjusting the sensitivity of the monitoring system, are considered. The main modules of the monitoring system software are described. Analysis of the imitative modeling results of the cracks registering processes as a function of size, shape, and the arrangement of cracks, the number of boundary contacts of the distributed sensor, the step of the grid, and the parameters of a digital filter are considered. Comparative analysis of the developed and standard EIT methods for surface cracks monitoring in constructive elements was performed.