A Novel Methodology for Spatial Damage Detection and Imaging Using a Distributed Carbon Nanotube-Based Composite Sensor Combined with Electrical Impedance Tomography
- 1.4k Downloads
This paper describes a novel non-destructive evaluation methodology for imaging of damage in composite materials using the electrical impedance tomography (EIT) technique applied to a distributed carbon nanotube-based sensor. The sensor consists of a nonwoven aramid fabric, which was first coated with nanotubes using a solution casting approach and then infused with epoxy resin through the vacuum assisted resin transfer molding technique. Finally, this composite sensor is cured to become a mechanically-robust, electromechanically-sensitive, and highly customizable distributed two-dimensional sensor which can be adhered to virtually any substrate. By assuming that damage on the sensor directly affects its conductivity, a difference imaging-based EIT algorithm was implemented and tailored to offer two-dimensional maps of conductivity changes, from which damage location and size can be estimated. The reconstruction is based on a newly defined adjacent current–voltage measurement scheme associated with 32 electrodes located along the boundary of the sensor. In this paper, we evaluate our methodology first by introducing well-defined damage where sections are either removed or narrow cuts are made on a series of sensor specimens. Finally, a more realistic damage scenario was investigated to show the capability of our methodology to detect impact damage on a composite laminate. The resulting EIT maps are compared to visual inspection and thermograms taken with an infrared camera.
KeywordsDistributed sensing Carbon nanotube Composite materials Nonwoven fabric Electrical impedance tomography Non-destructive evaluation Damage detection Difference imaging
The support of this collaborative research effort by the National Science Foundation, CMMI Division, Award # 1234830 (Dr. Kishor Mehta, Program Director) is greatly appreciated. The authors would like to thank Technical Fibre Products (TFP) for donating the nonwoven fabrics used in this research. We also would like to acknowledge Dr. Dirk Heider from Center for Composite Materials at University of Delaware for his supply of the infrared camera used in this research.
- 24.Dai, H., Schumacher, T., Thostenson, E: Carbon nanotube-based sensing composites for structural health monitoring of civil infrastructure using non-woven fabrics. In: Safety, Reliability, Risk and Life-Cycle Performance of Structures and Infrastructures, Proceedings of the 11th International Conference on Structural Safety and Reliability (ICOSSAR), New York, NY, USA, 16–20 June, 2013, p. 299Google Scholar
- 30.Ubertini, F., Laflamme, S., Ceylan, H., Materazzi, A.L., Cerni, G., Saleem, H., D’Alessandro, A., Corradini, A.: Novel nanocomposite technologies for dynamic monitoring of structures: a comparison between cement-based embeddable and soft elastomeric surface sensors. Smart Mater. Struct. 23, 045023 (2014)CrossRefGoogle Scholar
- 34.Harikumar, R., Prabu, R., Raghavan, S.: Electrical impedance tomography (EIT) and its medical applications: a review. Int. J. Soft Comput. Eng. 3, 2231–2307 (2013)Google Scholar
- 36.Vauhkonen, M.: Electrical impedance tomography and prior information. PhD Dissertation, Univeristy of Kuopio, Finland (1997)Google Scholar
- 41.Polydorides, N.: Image reconstruction algorithms for soft-field tomography. PhD Dissertation, University of Manchester Institute of Science and Technology, UK (2002)Google Scholar
- 43.Bera, T.K., Nagaraju, J.: A MATLAB-based boundary data simulator for studying the resistivity reconstruction using neighbouring current pattern. J. Med. Eng. 15 (2013)Google Scholar
- 44.Polydorides, N., Lionheart, W.R.: A Matlab toolkit for three-dimensional electrical impedance tomography: a contribution to the electrical impedance and diffuse optical reconstruction software project. Meas. Sci. Technol. 2002, 13 (1871)Google Scholar
- 48.ASTM Standard: D7136/D7136M-05, Standard Test Method for Measuring the Damage Resistance of a Fiberreinforced Polymer Matrix Composite to a Drop-Weight Impact Event. ASTM International, West Conshohocken (2005)Google Scholar
- 50.Titman, D.: Applications of thermography in non-destructive testing of structures. NDT E Int. 34, 149–154 (2001)Google Scholar
- 51.Grinzato, E.: State of the art and perspective of infrared thermography applied to building science. In: Meola, C. (ed.) Infrared Thermography Recent Advances and Future Trends, pp. 200–229. Bentham eBooks, New York (2012)Google Scholar