Performance Metrics for Structures-based Electrical ImpedanceTomography Measurements

Electrical impedance tomography maps the conductivity distribution of a domain by measurement of the voltage-current relationship on its boundary. It has been considered as an in-situ method for characterization of damage in engineered materials like polymer-matrix composites; yet, several challenges must be solved before this technique can transition to the aerospace sector. One challenge is our inability to estimate the optimal electrode coverage necessary to produce a desired inspection capability for a given geometry. Developing this capability requires distinguishability metrics to assess the performance of a given electrode configuration. In this work, we first develop metrics for polymer-matrix composite structures, then examine their efficacy with a simulation-based study. The results of the study confirm our expectations of the distinguishability of specific damage modes in the tested material and demonstrate how these metrics might one day inform estimates of the optimal electrode coverage for aerospace structures.