Thermoelastic damping in orthotropic and isotropic NEMS resonators accounting for double nonlocal thermoelastic effects

Ahmadi, Hamid; Rahimi, Zaher; Sumelka, Wojciech

doi:10.1080/01495739.2020.1853639

Cited by 5 publications

(5 citation statements)

References 33 publications

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“…So, only a few key values are selected and shown in Figure 3. As one of the key values for structural sti ness, it is shown that the de ection increases with the increase of internal characteristic scale parameter when the structural sti ness of the micro-beam is EI 10 −19 Nm 2 , or the exural rigidity gets weakening with the increase of the internal characteristic scale parameter, which is consistent with the basic assumptions of the nonlocal theory [17][18][19][20][21][22][23][24][25][26][27]. Nevertheless, if the structural sti ness is less than 10 −19 Nm 2 , the de ection decreases slightly that is not a reasonable phenomenon from the view of long-range interactions [17,18].…”

Section: Nonlocal Formulations Andsupporting

confidence: 78%

“…For example, the trend reverses when the structural sti ness is EI 8 × 10 −20 Nm 2 as compared with the case of EI 10 −19 Nm 2 . It implies a exural rigidity strengthening with the increase of the scale parameter, which is, however, inconsistent with the prediction of the nonlocal di erential constitutive model [19][20][21][22][23][24][25][26][27]. Hence, EI 8 × 10 −20 Nm 2 is not desirable in this example.…”

Section: Nonlocal Formulations Andcontrasting

confidence: 57%

“…Hence, the local cannot represent the original characteristics of the whole in the micro-/nano-scale, namely it is "nonlocality." e nonlocal theory has been applied extensively during the recent decades, of which almost all the research objects are micro-/nano-structures [19][20][21][22][23][24][25][26][27]. is is because the nonlocal theory contains the internal characteristic scale, and it is naturally suitable for the study of micro-/nano-mechanics.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On Nonlocal Vertical and Horizontal Bending of a Micro-Beam

Zhu

Chen

Zhao

et al. 2022

Mathematical Problems in Engineering

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The vertical and horizontal bending of micro-beams subjected to axial compressive and transverse concentrated loadings is a common lateral deformation in micro-/nano-engineering that plays a significant role in the design and optimization of micro-/nano-devices. The present study aims to investigate it using the nonlocal theory. For this purpose, the simplified mathematical model is developed, and the nonlocal differential constitutive equation is applied. Since the mechanical properties of micro-beams are different from those of macro-beams, the non-classical nonlocal bending moment is introduced to improve the classical bending formulation in order to adapt to the vertical and horizontal bending of micro-beams. The effects of the external load, external size, structural stiffness, and internal characteristic scale on the vertical and horizontal bending deformation including the midpoint deflection and critical compression are presented. The present analytical model and results are validated by the finite element method. It is shown that the critical compression decreases with increasing the internal characteristic scale. Moreover, the midpoint deflection varies remarkably with respect to the axial and transverse loadings, structural stiffness, internal characteristic scale, and external size. An obvious nonlocal scale effect is found, in which the internal characteristic scale cannot be neglected compared with the external size. Besides, a threshold value of the structural stiffness is determined, and the connotation of the nonlocal interaction requires that the structural stiffness shall not be lower than that threshold. A mutual restriction between structural stiffness and external loadings is observed in the vertical and horizontal bending. In particular, it is further proved that the classical continuum mechanics can not be used in micro-/nano-scaled mechanics through a strange phenomenon that is contrary to mechanical common sense in the calculation example. The study is expected to be beneficial to the design and application of micro-beams subjected to the vertical and horizontal bending.

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Section: Nonlocal Formulations Andsupporting

confidence: 78%

Section: Nonlocal Formulations Andcontrasting

confidence: 57%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On Nonlocal Vertical and Horizontal Bending of a Micro-Beam

Zhu

Chen

Zhao

et al. 2022

Mathematical Problems in Engineering

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“…In this paper, the non-local Euler-Bernoulli beam model is applied to study the free vibration of a DWCNT. The governing equations of a viscoelastic nano-beam under a longitudinal magnetic field based on non-local elasticity theory can be obtained as follows [43]:…”

Section: Theoretical Basismentioning

confidence: 99%

“…It introduces a non-local parameter for the influence of neighboring atoms or molecules on a material's mechanical behavior. The non-local theory has been successfully applied to various problems [42][43][44][45][46]. Its ability to accurately capture the size-dependent behavior of nanostructures makes it a valuable tool in the analysis and design of nanoscale systems.…”

Section: Introductionmentioning

confidence: 99%

Enhancing Sensitivity of Double-Walled Carbon Nanotubes with Longitudinal Magnetic Field

Ahmadi,

Rahimi,

Sumelka

2024

Applied Sciences

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In this study, the behavior of double-walled carbon nanotubes (DWCNTs) used as mass sensors is explored under various boundary conditions; particular attention is paid to the crucial topic of resonant nanomechanical mass sensors. In the presented approach, nanotubes are subjected to a distributed transverse magnetic force and supported by an elastic foundation. The impacts of the longitudinal magnetic field, elastic medium, and diverse physical parameters on the responsiveness of the sensors are assessed. Using the energy method, governing equations are formulated to determine the frequency shifts of the mass nanosensors. Our findings reveal significant variations in the frequency shifts due to a longitudinal magnetic field, which depends on the applied boundary conditions. This research holds significance in the design of resonant nanomechanical mass sensors and provides valuable insights into the interplay of factors affecting their performance. Through exploring the intricate dynamics of DWCNTs used as mass sensors and thus contributing to the broader understanding of nanoscale systems, the implications for advancements in sensor design are offered and applications are introduced.

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State-of-the-Art of Vibration Analysis of Small-Sized Structures by using Nonclassical Continuum Theories of Elasticity

Nuhu

Safaei

2022

Arch Computat Methods Eng

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Thermoelastic damping in orthotropic and isotropic NEMS resonators accounting for double nonlocal thermoelastic effects

Cited by 5 publications

References 33 publications

On Nonlocal Vertical and Horizontal Bending of a Micro-Beam

On Nonlocal Vertical and Horizontal Bending of a Micro-Beam

Enhancing Sensitivity of Double-Walled Carbon Nanotubes with Longitudinal Magnetic Field

State-of-the-Art of Vibration Analysis of Small-Sized Structures by using Nonclassical Continuum Theories of Elasticity

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