References of "Li, Z.Z"
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See detailProperties and mechanisms of self-sensing carbon nanofibers/epoxy composites for structural health monitoring
Wang, Y.L; Wang, Y.; Wan, B.L et al

in Composite Structures (2018), 200

In this paper, carbon nanofibers (CNFs) with high aspect ratio were dispersed into epoxy matrix via mechanical stirring and ultrasonic treatment to fabricate self-sensing CNFs/epoxy composites. The ... [more ▼]

In this paper, carbon nanofibers (CNFs) with high aspect ratio were dispersed into epoxy matrix via mechanical stirring and ultrasonic treatment to fabricate self-sensing CNFs/epoxy composites. The mechanical, electrical and piezoresistive properties of the nanocomposites filled with different contents of CNFs were investigated. Based on the tunneling conduction and percolation conduction theories, the mechanisms of piezoresistive property of the nanocomposites were also explored. The experimental results show that adding CNFs can effectively enhance the compressive strengths and elastic moduli of the composites. The percolation threshold of the CNFs/epoxy composites is 0.186 vol% according to the modified General Effective Media Equation. Moreover, the stable and sensitive piezoresistive response of CNFs/epoxy composites was observed under monotonic and cyclic loadings. It can be demonstrated that adding CNFs into epoxy-based composites provides an innovative means of self-sensing, and the high sensitivity and stable piezoresistivity endow the CNFs/epoxy composites with considerable potentials as efficient compressive strain sensors for structural health monitoring of civil infrastructures. [less ▲]

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See detailStrain monitoring of concrete components using embedded carbon nanofibers/epoxy sensors
Wang, Y.L.; Wang, Y.S.; Han, B.G. et al

in Construction and Building Materials (2018)

In this study, embedded strain sensors based on the principle of piezoresistivity were fabricated by epoxy-based composites filled with different contents of carbon nanofibers (CNFs). The piezoresistive ... [more ▼]

In this study, embedded strain sensors based on the principle of piezoresistivity were fabricated by epoxy-based composites filled with different contents of carbon nanofibers (CNFs). The piezoresistive performances and relevant parameters including gauge factor, linearity, repeatability and hysteresis of these sensors were investigated. A compensation circuit was proposed to eliminate the influence of temperature on sensing signals of the sensors. The CNFs/epoxy sensors were embedded into concrete cylinders to monitor their compressive strains under monotonic and cyclic loadings, thereby assessing practical applications of the CNFs/epoxy sensors as strain sensors for monitoring concrete structures. The results indicate that the sensors containing 0.58 vol% of CNFs, which have a gauge factor of 37.1, a linearity of 5.5%, a repeatability of 3.8% and a hysteresis of 6.3%, exhibited better piezoresistive performance compared to those containing 0.29 vol% of CNFs. The calibration and monitoring curves exhibited a consistent variation trend when the cylinders embedded with sensors were subjected to monotonic and cyclic loadings. This demonstrates that the CNFs/epoxy sensors have considerable potential to be used as embedded strain sensors for structural health monitoring of concrete structures. [less ▲]

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