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Numerical simulation and experimental validation of a large-area capacitive strain sensor for fatigue crack monitoring
Measurement Science and Technology
  • Xiangxiong Kong, University of Kansas
  • Jian Li, University of Kansas
  • Caroline Bennett, University of Kansas
  • William Colins, University of Kansas
  • Simon Laflamme, Iowa State University
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Publication Version
Accepted Manuscript
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A large-area electronics in the form of a soft elastomeric capacitor (SEC) has shown great promise as a strain sensor for fatigue crack monitoring in steel structures. The SEC sensors are inexpensive, easy to fabricate, highly stretchable, and mechanically robust. It is a highly scalable technology, capable of monitoring deformations on mesoscale systems. Preliminary experiments verified the SEC sensor’s capability in detecting, localizing, and monitoring crack growth in a compact specimen. Here, a numerical simulation method is proposed to simulate accurately the sensor’s performance under fatigue cracks. Such a method would provide a direct link between the SEC’s signal and fatigue crack geometry, extending the SEC’s capability to dense network applications on mesoscale structural components. The proposed numerical procedure consists of two parts: (1) a finite element (FE) analysis for the target structure to simulate crack growth based on an element deletion method; (2) an algorithm to compute the sensor’s capacitance response using the FE analysis results. The proposed simulation method is validated based on test data from a compact specimen. Results from the numerical simulation show good agreement with the SEC’s response from the laboratory tests as a function of the crack size. Using these findings, a parametric study is performed to investigate how the SEC would perform under different geometries. Results from the parametric study can be used to optimize the design of a dense sensor network of SECs for fatigue crack detection and localization

This is an author-created, un-copyedited version of an article accepted for publication/published in Measurement Science and Technology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at

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IOP Publishing Ltd
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Citation Information
Xiangxiong Kong, Jian Li, Caroline Bennett, William Colins, et al.. "Numerical simulation and experimental validation of a large-area capacitive strain sensor for fatigue crack monitoring" Measurement Science and Technology Vol. 27 (2016) p. 10
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