Abstract
The objective of this study is to design and validate distributed strain field monitoring using a patterned nanocomposite “sensing mesh” that is coupled with an electrical impedance tomography (EIT) measurement strategy and algorithm. Although EIT has been used in other studies and in conjunction with a piezoresistive thin film for spatial damage detection, different strain components cannot be directly extracted from reconstructed EIT conductivity maps. Therefore, this study seeks to address this issue by patterning piezoresistive graphene-based thin films to form a mesh-like pattern. The high aspect ratio of each nanocomposite grid interconnect acts as a linear distributed strain sensor, capable of resolving strains along the entire length and direction of the element. This study first began with the design, fabrication, and characterization of the strain sensing response of a graphene-based thin film of high strain sensitivity. Second, the strain-sensitive film was spray-coated onto patterned polymer substrates to form the sensing meshes, which were then subjected to load tests. Upon validating distributed strain field monitoring through EIT, its applicability for field implementation and damage characterization was also demonstrated by instrumenting sensing meshes in the column of a seven-story reinforced-concrete building subjected to shaking table earthquake excitations. The large-scale shaking table test results successfully validated distributed damage detection.
| Original language | English |
|---|---|
| Pages (from-to) | 1323-1339 |
| Number of pages | 17 |
| Journal | Structural Health Monitoring |
| Volume | 19 |
| Issue number | 5 |
| DOIs | |
| State | Published - Sep 1 2020 |
| Externally published | Yes |
Funding
Gupta Sumit 1 Vella Gianmarco 2 Yu I-No 3 Loh Chin-Hsiung 1 3 Chiang Wei-Hung 4 https://orcid.org/0000-0003-1448-6251 Loh Kenneth J 1 2 1 Department of Structural Engineering, University of California-San Diego, La Jolla, CA, USA 2 Material Science and Engineering Program, University of California-San Diego, La Jolla, CA, USA 3 Department of Civil Engineering, National Taiwan University, Taipei 4 Department of Chemical Engineering, National Taiwan University of Science & Technology, Taipei Kenneth J Loh, Department of Structural Engineering, University of California-San Diego, La Jolla, CA 92093-0085, USA. Email: [email protected] 10 2019 1475921719877418 © The Author(s) 2019 2019 SAGE Publications The objective of this study is to design and validate distributed strain field monitoring using a patterned nanocomposite “sensing mesh” that is coupled with an electrical impedance tomography (EIT) measurement strategy and algorithm. Although EIT has been used in other studies and in conjunction with a piezoresistive thin film for spatial damage detection, different strain components cannot be directly extracted from reconstructed EIT conductivity maps. Therefore, this study seeks to address this issue by patterning piezoresistive graphene-based thin films to form a mesh-like pattern. The high aspect ratio of each nanocomposite grid interconnect acts as a linear distributed strain sensor, capable of resolving strains along the entire length and direction of the element. This study first began with the design, fabrication, and characterization of the strain sensing response of a graphene-based thin film of high strain sensitivity. Second, the strain-sensitive film was spray-coated onto patterned polymer substrates to form the sensing meshes, which were then subjected to load tests. Upon validating distributed strain field monitoring through EIT, its applicability for field implementation and damage characterization was also demonstrated by instrumenting sensing meshes in the column of a seven-story reinforced-concrete building subjected to shaking table earthquake excitations. The large-scale shaking table test results successfully validated distributed damage detection. Electrical impedance tomography graphene large-scale testing nanocomposite patterning strain field strain sensing thin film Engineer Research and Development Center https://doi.org/10.13039/100006505 W912HZ-17-2-0024 edited-state corrected-proof The authors gratefully acknowledge the National Center for Research on Earthquake Engineering in Tainan, Taiwan, for giving us access and allowing our participation in the shaking table tests. The authors also thank Prof. Hyonny Kim (Department of Structural Engineering, University of California-San Diego) for providing access to the MTS-793 load frame and Mr Konstantinos Anagnostopoulos for his help with load testing. This study was also conducted in collaboration with Prof. Michael D. Todd (University of California-San Diego), Dr A. Drew Barnett and Dr Joey Reed (Elintrix), and Dr Anton Netchaev (Engineering Research & Development Center, U.S. Army Corp of Engineers). Author contributions S.G. developed the GNS thin film and implemented the EIT algorithm. He planned the experimental tests and analyzed the results with the help and supervision of K.J.L. W.-H.C. synthesized the GNS used in this study. S.G. and G.V. conducted the experiments together. K.J.L. collaborated with C.-H.L. and instrumented the sensing mesh in the large-scale test building that was subjected to shaking table tests in Taiwan. I.N.Y. assisted S.G., G.V., and K.J.L. to install the sensing mesh on the RC building and coordinated the large-scale tests. S.G. and K.J.L. wrote this article. K.J.L. is the lead investigator of this project (supported by the U.S. Army Corp of Engineers under principal investigator Prof. Michael Todd) and supervised the entire study. Declaration of conflicting interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Funding The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported by the U.S. Army Corp of Engineers under Research Cooperative Agreement W912HZ-17-2-0024, and partial support was also provided by the Jacobs School of Engineering, University of California-San Diego. ORCID iD Kenneth J Loh https://orcid.org/0000-0003-1448-6251 The authors gratefully acknowledge the National Center for Research on Earthquake Engineering in Tainan, Taiwan, for giving us access and allowing our participation in the shaking table tests. The authors also thank Prof. Hyonny Kim (Department of Structural Engineering, University of California-San Diego) for providing access to the MTS-793 load frame and Mr Konstantinos Anagnostopoulos for his help with load testing. This study was also conducted in collaboration with Prof. Michael D. Todd (University of California-San Diego), Dr A. Drew Barnett and Dr Joey Reed (Elintrix), and Dr Anton Netchaev (Engineering Research & Development Center, U.S. Army Corp of Engineers). The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported by the U.S. Army Corp of Engineers under Research Cooperative Agreement W912HZ-17-2-0024, and partial support was also provided by the Jacobs School of Engineering, University of California-San Diego.
| Funders | Funder number |
|---|---|
| Dr Anton Netchaev | |
| National Center for Research on Earthquake Engineering in Tainan | MTS-793 |
| University of California-San Diego | |
| Engineer Research and Development Center | |
| U.S. Army Corps of Engineers | W912HZ-17-2-0024 |
| University of California, San Diego | |
| Jacobs School of Engineering, University of California, San Diego |
Keywords
- Electrical impedance tomography
- graphene
- large-scale testing
- nanocomposite
- patterning
- strain field
- strain sensing
- thin film
