A modified model for dynamic instability of CNT based actuators by considering rippling deformation, tip-charge concentration and Casimir attraction

Sedighi, Hamid M.; Farjam, Nazanin

doi:10.1007/s00542-016-2956-6

Cited by 15 publications

(5 citation statements)

References 41 publications

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“…In this paper, an innovative stress-driven nonlocal mixture is proposed for Timoshenko nano-beams. Such a model is combination of local and nonlocal elastic phases and di ers from Eringen-like [11,12,13,14], strain gradient [15,16,17,18,19], couple stress models [20,21] and other approaches available in literature [22,23,24,25,26,27,28,29,30]. The need of the proposed stress-driven approach with mixture of local and nonlocal phases derives from a recent research [31] on behavior of the straindriven nonlocal model for bounded nanostructures, where the bending field is expressed as convolution of elastic curvature with an averaging kernel assuming an exponential expression.…”

Section: Introductionmentioning

confidence: 99%

A stress-driven local-nonlocal mixture model for Timoshenko nano-beams

Barretta

Caporale

Faghidian

et al. 2019

Composites Part B: Engineering

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A well-posed stress-driven mixture is proposed for Timoshenko nano-beams.The model is a convex combination of local and nonlocal phases and circumvents some problems of ill-posedness emerged in strain-driven Eringen-like formulations for structures of nanotechnological interest. The nonlocal part of the mixture is the integral convolution between stress field and a biexponential averaging kernel function characterized by a scale parameter.The stress-driven mixture is equivalent to a di erential problem equipped with constitutive boundary conditions involving bending and shear fields.Closed-form solutions of Timoshenko nano-beams for selected boundary and loading conditions are established by an e ective analytical strategy. The numerical results exhibit a sti ening behavior in terms of scale parameter.

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Section: Introductionmentioning

confidence: 99%

A stress-driven local-nonlocal mixture model for Timoshenko nano-beams

Barretta

Caporale

Faghidian

et al. 2019

Composites Part B: Engineering

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“…CNTs have potential for broad application in ultra-small devices including, but not limited to, sensor (Ali-Akbari et al, 2019;Kang et al, 2017), resonators (Besley, 2020;Ouakad & Younis, 2010), tweezers (Farrokhabadi et al, 2014;Kim & Lieber, 1999), probes (Y. Liu et al, 2017), actuators (Sedighi & Farjam, 2017) and switches (Dequesnes et al, 2004). With the new demands for ultra-small high accuracy devices, miniature resonators become the building block of modern instruments such as sensors (Hajjam & Pourkamali, 2011;Qian et al, 2016), accelerometers (Tocchio et al, 2011), and communication and signal processing devices (Mestrom et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Oscillations of CNT Nano-resonator Based on Nonlocal Elasticity: The Energy Balance Method

Goharimanesh

Koochi

2021

Rep. Mech. Eng.

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This paper deals with investigating the nonlinear oscillation of carbon nanotube manufactured nano-resonator. The governing equation of the nano-resonator is extracted in the context of the nonlocal elasticity. The impact of the Casimir force is also incorporated in the developed model. A closed-form solution based on the energy balance method is presented for investigating the oscillations of the nano-resonator. The proposed closed-form solution is compared with the numerical solution. The impact of influential parameters including applied voltage, Casimir force, geometrical and nonlocal parameters on the nano resonator’s vibration and frequency are investigated. The obtained results demonstrated that the Casimir force reduces the nano-resonator frequency. However, the nonlocal parameter has a hardening effect and enhances the system’s frequency.

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“…Wang and Wang simulated rippling formation and proposed a bending moment-curvature relationship of CNTs [23] . Many researchers have used this model for simulating the rippling phenomenon [24][25][26][27][28] . Soltani et al [24] investigated the transverse vibration of single-walled carbon nanotubes by considering the rippling bending.…”

Section: Introductionmentioning

confidence: 99%

“…The dynamic performances singlewalled CNT manufactured actuators with rippling deformation were investigated in Ref [ 26] . In another research, by considering rippling deformation, Sedighi and Farjam explored the dynamic pull-in properties of nanoscale actuators [27] . Under rippling deformation, Ghaffari and Abdelkefi examined the dynamic response of CNT bases sensors in magnetic and thermal conditions [28] .…”

Section: Introductionmentioning

confidence: 99%

Stability Analysis of CNT Based Nano-Actuator Under Magnetic Field and Rippling Deformation

Koochi

2021

Journal of Modern Nanotechnology

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Objective The widespread use of carbon nanotube-fabricated electromechanical systems has resulted in new operating scenarios for these structures, such as the presence of an external magnetic field. Also, rippling can significantly impact the performance of carbon nanotube-based actuators. These critical phenomena, however, are frequently overlooked in theoretical beam models. This paper simulates the electromagnetic instability of a carbon nano-tube-made actuator subjected to an external magnetic field. As the rippling bending may affect the stability performances of the nano-actuator, the influence of the rippling phenomenon is considered in the governing equation. Also, the impact of van der Waals force is incorporated in the simulation. Methods The governing equation of carbon nano-tube-manufactured nano-actuator is developed in terms of bending moment and lateral forces. Rippling is a wavelike deflection of bent carbon nanotubes on their inner arc. This configuration is crucial for large deformations, both globally and locally. The classical linear relationship between the bending and curvature cannot be employed for rippled CNT. Therefore, a modified non-linear curvature-moment relationship is used in the developed model. The impacts of the magnetic field, electrical force and van der Waals attraction are incorporated as lateral loads. The induced transverse load on the carbon nanotube due to a constant longitudinal magnetic field is simulated by using the Maxwell electrodynamics equations. Finally, the constitute equation of the nano-actuator is obtained which is a non-linear ordinary differential equation. A semi-analytical solution based on the Galerkin method is presented to solve the system’s non-linear governing equation. Results The proposed model is confirmed by comparing the resulting result to experimental data. Then, the influences of van der Waals interaction, the longitudinal magnetic flux, and rippling bending on the electromagnetic instability parameters of the nano-actuator are studied. The obtained results demonstrate that reveals that the van der Waals force reduces the instability deflection. Moreover, imposing an external magnetic field decreases the instability voltage of the system. Similarly, the instability voltage of the nano-actuator lessens by considering the rippling effect. Conclusion A mathematical model is established to study the instability of a CNT-made actuator in a magnetic environment. The model accounts for the longitudinally magnetic field using suitable body forces and the van der Waals interactions. The proposed model also takes into account the influence of rippling bending. The obtained results demonstrated that both magnetic flux and rippling phenomena reduce the instability voltage of the nano-actuator.

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A modified model for dynamic instability of CNT based actuators by considering rippling deformation, tip-charge concentration and Casimir attraction

Cited by 15 publications

References 41 publications

A stress-driven local-nonlocal mixture model for Timoshenko nano-beams

A stress-driven local-nonlocal mixture model for Timoshenko nano-beams

Nonlinear Oscillations of CNT Nano-resonator Based on Nonlocal Elasticity: The Energy Balance Method

Stability Analysis of CNT Based Nano-Actuator Under Magnetic Field and Rippling Deformation

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