Electrical impedance spectroscopy for structural health monitoring

Abstract

In-situ structural health monitoring systems on vehicles have the potential to enable on-demand material state awareness capability and eliminate the need for lengthy and costly down-times. Further, the information collected from a structural health monitoring system can be used to predict the remaining useful life of a structure or component. Electrical impedance spectroscopy is an emerging method of interrogating carbon fiber reinforced polymer composite materials subject to cyclic loading to determine the current damage state. This technique has the benefit of using the composite itself as the sensing material, thereby not requiring additional sensing material be placed into the composite. Information can be extracted from changes in both the phase and the impedance magnitude of the signal. Previous work found that special care must be taken to ensure that damage to the leads does not affect the results. In this work, a single interrogation path is examined to determine the usefulness of the single-path approach and the nature of the changes in impedance as they relate to fatigue life.