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Vibrational behavior of defective and repaired carbon nanotubes under thermal loading: A stochastic molecular mechanics study

Payandehpeyman, J ; Sharif University of Technology | 2021

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  1. Type of Document: Article
  2. DOI: 10.1016/j.mechmat.2021.104058
  3. Publisher: Elsevier B.V , 2021
  4. Abstract:
  5. Carbon nanotubes (CNTs) are promising candidates for high-resolution mass nanosensors owing to their unique vibrational behavior. The structural characteristic (e.g. defect type and density) and working temperature have a significant effect on the natural frequency of CNT-based sensors. Herein, a stochastic approach based on novel finite element and molecular mechanics simulations is implemented to model the effect of temperature and structural characteristics of single-wall CNTs including defects (vacancy defect with different densities) and chirality (zigzag and armchair) on their vibrational behavior. The results show that the vacancy defects exert a significant deterioration of the average natural frequency to 79.5% and 81.5% of a perfect structure for armchair and zigzag configuration, respectively. This is combined with a significant scattering of natural frequencies that limits the wide application of CNTs for high-resolution mass nanosensors. We originally showed that bond reconstruction/repairing plays an important role in engineering the resonance. The results demonstrate that a binding recovery of a double vacancy improves the average CNTs natural frequency response close to a perfect CNT (93.8% and 94.6% of a perfect CNT for armchair and zigzag configuration, respectively). Moreover, the reconstruction reduces by one-third the standard deviation of CNT natural frequency that increases the accuracy of nano-sensors for detecting very small masses down to zeptogram. These findings can pave the way to design ultra-high resolution CNT-based nano-sensors with different sensitivity using defective and repaired/reconstructed CNTs. © 2021
  6. Keywords:
  7. Damage detection ; Deterioration ; Frequency response ; Nanosensors ; Natural frequencies ; Single-walled carbon nanotubes (SWCN) ; Stochastic models ; Stochastic systems ; Structural health monitoring ; High resolution ; Mass nanosensor ; Nano-sensors ; Single-walled carbon ; Single-walled carbon nanotube ; Structural characteristics ; Vacancy Defects ; Vibrational behavior ; Vibrations analysis ; Zigzag configuration ; Vibration analysis
  8. Source: Mechanics of Materials ; Volume 163 , 2021 ; 01676636 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0167663621002829