Carbon fiber grid sensor for structural deformation using piezoresistive behavior of carbon fiber

Abstract

Monitoring the location and extent of mechanical deformations is an important issue in large-scale structures, such as civil infrastructures and aircraft. This paper presents a study on real-time, condition-based structural health monitoring with carbon fiber grid utiliziling the electromechanical behavior of carbon fiber. Carbon fiber holds intrinsic self-sensing capability with piezoresistive behavior which is the electrical resistance change subjected to tensile strain. Arranging the carbon fibers into a sensor grid enabled monitoring physical deformations of large-scale structures by expanding 1D tow-scale piezoresistive behavior into 2D/3D surficial self sensing. Electrically equivalent circuit modeling was proposed as regarding carbon fiber as an electrical resistor, and the circuit model helped numerical analysis for the apparent electromechanical gage factor. The apparent gage factor was correlated to the initial electrical network so that manipulating the density of the sensing grid controlled the sensitivity.