Abstract
Novel coaxial cable sensors that feature high sensitivity and high spatial resolution are developed for health monitoring of concrete structures using a time-domain reflectometry (TDR). The new sensor was designed based on the topology change of its outer conductor, which was fabricated with tightly wrapped commercial tin-plated steel spiral covered with solder. The cracks that developed within concrete structures will lead to out-of-contact of local steel spirals. This topology change results in a large impedance discontinuity that can be measured with a TDR. A simplified equivalent transmission line model and numerical full-wave simulations using finite-difference time-domain techniques were used to optimize the sensor design. The sensors under test demonstrated high sensitivity and the capability of multiple-crack detection. A plasma-sprayed coating technique was employed to improve sensor uniformity. Engineering implementation issues, e.g., signal loss, signal postprocessing, and sensor design optimization, were also addressed.
Original language | English |
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Pages (from-to) | 2714-2725 |
Number of pages | 12 |
Journal | IEEE Transactions on Instrumentation and Measurement |
Volume | 58 |
Issue number | 8 |
DOIs | |
Publication status | Published - 3 Jul 2009 |
Externally published | Yes |
Keywords
- Coaxial cable
- Crack/strain sensor
- Plasma spray
- Sensitivity
- Signal loss
- Spatial resolution
- Time-domain reflectometry (TDR)
ASJC Scopus subject areas
- Instrumentation
- Electrical and Electronic Engineering