Electrical Impedance Spectroscopy for Structural Health Monitoring
Structural heath monitoring (SHM) can provide an estimate of the state of damage in a structure, and of the remaining useful life of that structure. The work presented here is an investigation of a proposed new SHM technique for composite structures composed of carbon-fiber-reinforced-polymers (CFRP). Electrical impedance spectroscopy (EIS) is employed to estimate the damage state of the composite. No modification to current CFRP processing methods is required, nor is the proposed technique invasive or destructive. EIS interfaces can be either permanently attached or temporarily connected. We hypothesize that EIS has the potential to be more sensitive and selective for damage detection by using a full complex-plane analysis, considering both impedance magnitude and phase angle. This is in contrast to electrical SHM approaches employing resistance measurement, the real component of impedance, which ignores phase angle and reactance information. In order to test our hypothesis we implemented three different experiments to evaluate the effectiveness of the EIS technique: (1) specimen load sensitivity; (2) specimen damage sensitivity; and (3) specimen fatigue sensitivity. Multiple electrical interrogation paths through the specimen are considered.
KeywordsElectrical impedance spectroscopy Structural health monitoring Carbon fiber Fatigue state Damage state detection Load state detection
The authors would like to acknowledge the expert and valuable assistance of Mr. Wosen Wolde with the design, production, assembly, and trouble shooting of the electronics switching board.
- 2.Liu A, Wang KW, Bakis CE (2010) Damage detection of epoxy polymer via carbon nanotube fillers and external circuitry. In: 18th international conference on composites or nano engineering, Anchorage, AlaskaGoogle Scholar
- 9.Na S, Tawie R, Lee HK (2011) Impedance-based non-destructive evaluation of the FRP adhesive joints in corrosive environment with re-usable technique. In: SPIE smart structures and materials + nondestructive evaluation and health monitoring. International Society for Optics and Photonics, pp 79811B–79811BGoogle Scholar
- 10.Zhong CH, Croxford AJ, Wilcox PD (2012) Inductively coupled transducer system for damage detection in composites. In: SPIE smart structures and materials + nondestructive evaluation and health monitoring. International Society for Optics and Photonics, pp 83480H–83480HGoogle Scholar
- 11.Grimberg R, Premel D, Lemistre MB, Balageas DL, Placko D (2001) Compared NDE of damages in graphite/epoxy composites by electromagnetic methods. In: 6th annual international symposium on NDE for health monitoring and diagnostics. International Society for Optics and Photonics, pp 65–72Google Scholar