Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory

The thermo-elastic damping is a dominant source of internal damping in microelectromechanical systems (MEMS) and nano-electromechanical systems (NEMS). The internal damping cannot neither be controlled nor minimized unless either mechanical or geometrical properties are changed. Therefore, a novel F...

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Дата:2017
Автори: Rahimi, Z., Rashahmadi, S.
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Опубліковано: Інститут механіки ім. С.П. Тимошенка НАН України 2017
Назва видання:Прикладная механика
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Цитувати:Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory / Z. Rahimi, S. Rashahmadi // Прикладная механика. — 2017. — Т. 53, № 6. — С. 133-141. — Бібліогр.: 23 назв. — англ

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spelling irk-123456789-1741422021-01-06T01:26:05Z Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory Rahimi, Z. Rashahmadi, S. The thermo-elastic damping is a dominant source of internal damping in microelectromechanical systems (MEMS) and nano-electromechanical systems (NEMS). The internal damping cannot neither be controlled nor minimized unless either mechanical or geometrical properties are changed. Therefore, a novel FGMNEM system with a controllable thermo-elastic damping of axial vibration based on Eringen nonlocal theory is considered. The effects of different parameter like the gradient index, nonlocal parameter, length of nanobeam and ambient temperature on the thermo-elastic damping quality factor are presented. It is shown that the thermo-elastic damping can be controlled by changing different parameter. Термопружне демпфування є головним джерелом внутрішнього демпфування в мікроелектромеханічних і наноелектромеханічних системах. Внутрішнє демпфування не може бути ні кероване, ні мінімізоване, поки механічні і геометричні властивості матеріалу не є змінними. Тому розглянуто осьові коливання балки з нового матеріалу – функціонально градієнтного матеріалу з врахуванням наноелектромеханічних явищ – в рамках нелокальної теорії Ерінгена. Розглянуто вплив різних параметрів – показника градієнтості, параметрів нелокальності, довжини нанобалки, температури навколишнього середовища – на коефіцієнт термопружного демпфування. Показано, що термопружне демпфування може бути кероване зміною цих параметрів. 2017 Article Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory / Z. Rahimi, S. Rashahmadi // Прикладная механика. — 2017. — Т. 53, № 6. — С. 133-141. — Бібліогр.: 23 назв. — англ 0032-8243 http://dspace.nbuv.gov.ua/handle/123456789/174142 en Прикладная механика Інститут механіки ім. С.П. Тимошенка НАН України
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
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description The thermo-elastic damping is a dominant source of internal damping in microelectromechanical systems (MEMS) and nano-electromechanical systems (NEMS). The internal damping cannot neither be controlled nor minimized unless either mechanical or geometrical properties are changed. Therefore, a novel FGMNEM system with a controllable thermo-elastic damping of axial vibration based on Eringen nonlocal theory is considered. The effects of different parameter like the gradient index, nonlocal parameter, length of nanobeam and ambient temperature on the thermo-elastic damping quality factor are presented. It is shown that the thermo-elastic damping can be controlled by changing different parameter.
format Article
author Rahimi, Z.
Rashahmadi, S.
spellingShingle Rahimi, Z.
Rashahmadi, S.
Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory
Прикладная механика
author_facet Rahimi, Z.
Rashahmadi, S.
author_sort Rahimi, Z.
title Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory
title_short Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory
title_full Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory
title_fullStr Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory
title_full_unstemmed Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory
title_sort thermoelastic damping in fgm nano-electromechanical system in axial vibration based on eringen nonlocal theory
publisher Інститут механіки ім. С.П. Тимошенка НАН України
publishDate 2017
url http://dspace.nbuv.gov.ua/handle/123456789/174142
citation_txt Thermoelastic damping in FGM nano-electromechanical system in axial vibration based on Eringen nonlocal theory / Z. Rahimi, S. Rashahmadi // Прикладная механика. — 2017. — Т. 53, № 6. — С. 133-141. — Бібліогр.: 23 назв. — англ
series Прикладная механика
work_keys_str_mv AT rahimiz thermoelasticdampinginfgmnanoelectromechanicalsysteminaxialvibrationbasedoneringennonlocaltheory
AT rashahmadis thermoelasticdampinginfgmnanoelectromechanicalsysteminaxialvibrationbasedoneringennonlocaltheory
first_indexed 2025-07-15T11:01:17Z
last_indexed 2025-07-15T11:01:17Z
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fulltext 2017 ПРИКЛАДНАЯ МЕХАНИКА Том 53, № 6 ISSN0032–8243. Прикл. механика, 2017, 53, № 6 133 Z . R a h i m i , S . R a s h a h m a d i 1 THERMOELASTIC DAMPING IN FGM NANO-ELECTROMECHANICAL SYSTEM IN AXIAL VIBRATION BASED ON ERINGEN NONLOCAL THEORY 1 Mechanical Engineering Department, Urmia University, Urmia, Iran; e-mail: s.rashahmadi@urmia.ac.ir Abstract. The thermo-elastic damping is a dominant source of internal damping in mi- cro-electromechanical systems (MEMS) and nano-electromechanical systems (NEMS). The internal damping cannot neither be controlled nor minimized unless either mechanical or geometrical properties are changed. Therefore, a novel FGMNEM system with a controlla- ble thermo-elastic damping of axial vibration based on Eringen nonlocal theory is consid- ered. The effects of different parameter like the gradient index, nonlocal parameter, length of nanobeam and ambient temperature on the thermo-elastic damping quality factor are pre- sented. It is shown that the thermo-elastic damping can be controlled by changing different parameter. Key words: FGM nanobeam, Eringen nonlocal theory, axial vibrations, thermoelastic damping. 1. Introduction. Nowadays MEMS and NEMS industries are playing important roles in scientific and engineering communities. There are a lot of advantages that make MEMS and NEMS com- mercialization attractive. Ink jet printer heads, micropumps, airbag accelerometers and mi- cro sensors are a few examples of devices which these systems have successfully replaced more conventional systems [1]. There are different kind of loss mechanism in MEMS and NEMS which classified into the two categories: extrinsic and intrinsic losses. [2]. internal damping cannot neither be controlled norminimized unless either mechanical or geometrical properties are changed [3]TED is a dominant source of intrinsic damping in MEMS. [4] and NEMS. [5] working under vacuum condition. [6]. It has been identified as one of important loss mechanisms in NEMS and MEMS [7]. From the other hand development of low-power, high performance MEM and NEM systems are of great importance [8] so TED is a very active research ap- proach [7]. Lifshitz and Roukes [9] derived an analytical expression for the QF of TED in- micro-beams and studied the effect of different geometrical parameters. Saeedi vahdat et al. [4] study the effects of axial and residual stresses on thermoelastic damping in capacitive micro-beam. Lepage et al. [10] studied thermoelastic effects in a vibrating beam acceler- ometer that modelled using finite elements. Nayfeh and Younis [11] presented ananalytical expression for the QF of micro-plates of general shapes and boundary conditions due to TED. Rezazadeh et al. [6] studied thermoelastic damping in a micro-beam resonator using modified couple stress theory and also thermoelastic damping in capacitive micro-beam resonators using hyperbolic heat conduction model [12]. As can be seen there are a lot of work has been done on the TED of transverse vibration but investigations about longitudinal vibrations are few in comparison with it. These vibra- tions are quite different [13]for example, the natural frequencies in transversal vibration are much lower than that of longitudinal vibration [13]and probably can achieve high QF. [14]. TED of the longitudinal vibration of micro beams is studied by maroofi et al. [14] and they showed increasing of the ambient temperature and length of micro beam increases the QF. 134 In the present work, by considering the coupled equations of motion and heat conduc- tivity, TED of nano FGM beam’s axial vibration based on nonlocal theory has been pre- sented and has been proposed a novel FGMNEM system, with a controllable thermo-elastic damping of axial vibration. The Material properties of the FGM beam vary continuously along the beam thickness according to the power law distribution. The coupled equations is solved by Galerkin method for a clamped-clamped boundary condition and finally, the effects of different pa- rameters like gradient index, nonlocal parameter, length of nano beam and ambient tempera- ture has been presented on the QF. 2. Formulation. Consider functionally graded clamped nanobeam of length ,L width b, and thickness h. Material properties of the beam vary continuously along the beam thickness are functions of z according to the power law distribution [15]: 2 ( ) ( ) , 2 m l u u z h p z p p p h        where subscripts u and l refer to material properties of the upper and lower surfaces respec- tively. m is a non-negative number that dictates the material variation profile through the thickness of the beam. The general strain field results from both mechanical and thermal effects [16, 17] ,M T ij ij ije e e  (1) where M ije and T ije are mechanical and thermal strain as bellow: 0 1 ; ( )( ) , ( ) ( ) M T ij ij kk ij ij ije e z T T E z E z           (2) where  is passion’s ratio, E is young modulus,  is coefficient of the linear thermal expan- sion and 0T is equal to the ambient temperature so the stress-strain relation is as follow [16]: 02 (3 2 ) ( )( ) .ij kk ij ij ije e z T T            (3) For both plane strain and plane stress condition we have [18]: 0[ ] ( ).ef M T ef xx xx xx xxE e e E e T T      (4) In plane stress condition ( ) ( )efE z z  and in plane strain condition ( ) ( ) / (1 )efE z z    and where 25 , / (1 )efb h E E    otherwise .efE E 2.1 Nonlocal theory. According to Eringen [19 – 21], the stress field at a point x in an elastic continuum not only depends on the strain field at the point but also on strains at all other points of the body. Eringen attributed this fact to the atomic theory of lattice dynamics and experimental observations on phonon dispersion. Thus, the nonlocal stress tensor com- ponents σij at point x are expressed as: ( ) ( , ) ( ) ,ij ij v x k x x t x dx     (5) where tij(x) are the components of the classical macroscopic stress tensor at point x and the kernel function ( , )k x x  represents the nonlocal modulus, x x  being the distance (in Euclidean norm) and τ is a material constant that depends on internal and external character- istic lengths (such as the lattice spacing and wavelength, respectively). It is possible (see Eringen [20]) to represent the integral constitutive relations in an equivalent differential form as: 135 2 2 02 1 ( ( ) ),ef xx xxE e e a x            (6) where a is an internal characteristic length and 0e is a constant. Now based on the Eringen nonlocal theory Eq. (4) changes to following form. 2 02 1 [ ] ( )( ).ef M T ef ef xx xx xx xxE e e E e E z T T x               (7) The equation for the axial motion of the beam in the absence of external force can be obtained as. [16]: 2 1 2 ( , ) , N u x t I x t      (8) where ( , )u x t is the axial displacement, ( )z is the mass per unit length, N is the axial force per unit length and I is as bellow, /2 1 /2 ; ( ) , h xx A h N dA I b z dz      (9) where A is the cross-sectional area of the beam. Integrating Eq. (6) with respect to area gives the following relation: 2 1 2 02 1 ( ),xxN B e B T T x           (10) where /2 1 /2 ( ) h ef h B b E z dz    and /2 2 /2 ( ) (z) h ef h B b E z dz    . Using Eqs. (7) – (9), the equation of axial vibration can be found in terms of displace- ment 2 4 2 1 1 1 2 02 2 2 2 ( , ) ( , ) ( , ) ( ), u x t u x t u x t I I B B T T xt t x x               (11) where 0  Eq. (10) reduces to the classic form. In the other hand the heat conduction equation without any thermal source is. [16]: , 0 ( ) ( ) ( ) ( ) , 1 2ii ii E z k z c z z T e          (12) where k and c are thermal conductively and specific heat constant at a constant volume. Eq. (11) in the form of displacement obtained as: 2 2 02 ( ) ( ) ( ) ( ) ( ) . 1 2 E z u k z z c z z T t x tx                 (13) By using the following non-dimensional parameters: ˆ ; u u l  ˆ ; x x l  0 ˆ ; T   0 ˆ ; t t t  2 2 0 ( ) (1 )(1 ) . ( ) z L t E z      The dimensional-less form of coupled Eqs. (10), (12) obtains as bellow: 2 2 4 1 2 3 42 2 2 2 ˆˆ ˆ ˆ = ; ˆ ˆˆˆ ˆ u u u D D D D xx t t x           (14a) 136 2 2 1 2 32 ˆ ˆ ˆ , ˆ ˆˆˆ u C C C t x tx          (14b) where D and C coefficients are as: 2 01 1 1 2 3 1 42 2 0 0 ; ; ; ; B TB L I D D D I D L L t t L      0 0 0 1 2 32 0 0 ( ) ( ) ( ) ( ) ; ; . (1 2 ) efk z T z c z T E z T C C C L t t        3. Numerical solution. To solve the coupled equation Galerkin method has been used. Based on the Galerkin method: 1 1 1 1 ˆˆ ˆ ˆ ˆ ˆ ˆˆ ˆ ˆ ˆ ˆ ˆ ˆ( , ) ( ) ( ) ( ) ( ); ( , ) ( ) ( ) ( ) ( ), N M n n n n m m m m n n m m u x t x a t x a t x t x b t x b t                  (15) where ˆ( )n x , ˆ( )m x are the suitable shape functions and ˆ( )na t , ˆ( )mb t are time dependent coefficients. The shape functions satisfy the both end clamped boundary conditions of our problem so the form of they is as bellow: ˆ ˆ ˆ ˆ( ) sin( ); ( ) sin( ).n mx n x x m x     (16) Substituting Eq. (15) into Eq. (14) and multiplying Eq. (14a) into ˆ( )i x and Eq. (15) into ˆ( )j x and integrating outcome from 0 to 1 and also considering first mode shape of displacement and second one of thermo leads to: 3 4 1 1 1 2 2 1 2 2 2 3 1 ˆ ˆ ˆ ˆ ˆ ˆ (- ) ( ) ( ) ( ) 0; ( ) ( ) ( ) 0,D D a t D a t D b t C b t C b t C a t        (17) By considering ˆ 1 ˆ( ) ta t ae and ˆ 2 ˆ( ) tb t be Eq. (17) changes to the following form: 2 3 4 1 2 1 2 3(( ) ) 0; ( ) 0.D D s D a D b C C s b C sa        (18) So the natural frequencies of the system obtain by solving Eq. (18). The D and C coef- ficients are as bellow: 1 1 1 1 2 2 0 0 1 1 3 3 4 4 0 0 ˆ ˆ ˆ ˆ ˆ ˆ( ) ( ) ; ( ) ( ) ; ˆ ˆ ˆ ˆ ˆ ˆ ( ) ( ) ; ( ) ( ) ; n i m i n i n i D D x x dx D D x x dx D D x x dx D D x x dx                  1 1 1 1 1 2 2 3 3 0 0 0 ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ( ) ( ) ; ( ) ( ) ; ( ) ( ) .m j m j n jC C x x dx C C x x dx C C x x dx           4. Results. In this section the numerical results has been presented. According to the power-law distribution of a material’s property, as an example, variation of the elastic modulus and thermal conductivity through the thickness with different material-variation profile parame- ter m is shown in Fig. 1. As can be noticed, the variation of a material property can be en- hanced via manipulating the control parameter m. The FGM nano beam has been composed of Nickel and silicon nitride. Its property varying through the thickness based on the power 137 low. Its bottom and upper surface is pure nickel and pure silicon nitride respectively. Mate- rials properties have been presented in Table 1. Fig. 1. Variation of the elastic modulus and thermal conductivity through the thickness with different material-variation profile parameter m. Geometrical and material properties. Table 1 Material Nickel [14] Silicon nitride [22] Density (kg/m3) 8900 2300 Thermal conductivity (w/mk) 92 30 Young modulus(Gpa) 210 310 Thermal expansion (1/k)× 10-6 13 3.4 Specific heat at constant volume (j/kgk) 438 680 Poisson’s ratio 0,31 0,27 According to the complex frequency approach, quality factor of thermo-elastic damping (QTED) can be achieved as [6, 23]: 1 1 Re( ) . 2 2 Im( )TEDQ      (19) To validate our results a comparison has been made with the results of Maroofi et al. [14] in Table. 2 for silicon micro beam where 200μm, 169Gpa, 150 w / mk,L E k   3695 j / kgk, 2300 kg / m , 0,28c     and 62,6 10 .   As it can be seen there is a good agreement between them. A comparison between quality factor (QTED×106) in longitudinal vibration for silicon beam. Table 2 Temperature (T0) Maroofi et al. [47] present 300 K 2,861 3,107 400 k 2,146 2,331 In Fig. 2 the effects of gradient index ( 0 40)m   for three value of nonlocal parameter 2( 0, 24 nm )  have been showed. As it can be seen increasing of gradient index increases 138 the quality factor in the nonlocal and classic theory. For gradient index between 0 – 10 the variation of the TEDQ is large but as the gradient index increases the diagram will be linear. Note that 0  presents classic theory and where 0m  the beam is pure nickel and by increasing gradient index the silicon bromide’s present increases. Fig. 3 shows the effects of nonlocal parameter on the quality factor. As there is no value has been introduced for the FGM beam so here the nonlocal parameter has been chosen between 0 – 4 nm2. As it is visi- ble increasing of  causes increase in the TED.Q Comparison of Fig. 3, a and Fig. 3, b shows that variation of  for 20 nmL  has lower effects than 10nmL  on the TED.Q This is means that increasing of the length decreases the effects of nonlocal parameter on the TED.Q Fig. 2. Effects of gradient index on the thermo-elastic damping quality factor where 010nm, 300 K.L T  Fig. 3. Effects of nonlocal parameter on the thermo-elastic damping quality factor a: 0 010 nm, 300 kb : 10 nm, 300 K.L T L T    Effects of length variation have been showed in Fig. 4, where length varies from 10 – 100 nm and gradient index is 0, 2, 4,10.m  As expected decreasing of length causing decrease in TED.Q As it can be seen increasing of the gradient index decreases this variation. In other 139 hand it can be found that length variation’s effects on the TEDQ decreases as the silicon- nitride’s present of the FGM beam increases. In Fig. 5 ambient temperature versus TEDQ is showed for nickel nano beam based on classic and Eringen nonlocal theory ( 0, 0 and 0, 2)m m     and the FGM nano beam based on classic and Eringen nonlocal theory ( 2, 0 and 2, 2).m m     It is visible by increasing of ambient temperature the QTED decreases. Also it can be seen that by increasing of T0 the effects of gradient index and nonlocal parameter on the TEDQ de- creases. In table 3 TEDQ in the 0 200T  and 500 K and also the difference of this two qual- ity factor ( TED1Q – TED2Q ) has been showed. This table shows that by increasing of gradi- ent index and nonlocal parameter the effects of ambient temperature’s variation on the TEDQ increases. Fig. 4. Length variation versus thermo-elastic damping quality factor (μ=0). Fig. 5. Ambient temperature versus thermo-elastic damping quality factor ( 10 nm).L  140 TEDQ of 0 200 & 500T  for different values of gradient index and nonlocal parameter. Table 3 m 2(nm ) TED1Q 0( 200K)T  TED2Q 0( 500K)T  TED1Q – TED2Q 0 1456 582,5 873,5 2 1586 634,5 951,5 0 4 1706 682,5 1023,5 0 1818 727,1 1090,9 2 1950 779,8 1170,2 2 4 2074 829,4 1244,6 0 2116 846,2 1269,8 2 2253 901 1352 4 4 2383 953,1 1429,9 5. Conclusion. Thermoelastic damping of axial vibration of the FGM nano beam has been presented based on the Eringen nonlocal theory. It has been composed of Nickel and silicon nitride. Its property varying through the thickness based on the power low. Its bottom and upper sur- face is pure nickel and pure silicon nitride respectively. The effects of gradient index, nonlocal parameter, Length of the beam and ambient temperature has been presented on the thermo-elastic damping quality factor. In the other word a FGMNEM system, with a con- trollable thermo-elastic damping of axial vibration based on Eringen nonlocal theory has been presented and has been showed that increasing of gradient index (increasing of silicon bromide’s present), nonlocal parameter and length of the nano beam, increases the quality factor and increasing of ambient temperature decreases it. Also is showed that by increasing of ambient temperature decreases the effects of gradient index and nonlocal parameter and increasing of the gradient index decreases the effects of the nano beam’s length variation, on the TED.Q The achieved results can be used as a design implement for the designers to con- trol TED. РЕЗЮМЕ . Термопружне демпфування є головним джерелом внутрішнього демпфування в мік- роелектромеханічних і наноелектромеханічних системах. Внутрішнє демпфування не може бути ні кероване, ні мінімізоване, поки механічні і геометричні властивості матеріалу не є змінними. Тому розглянуто осьові коливання балки з нового матеріалу – функціонально градієнтного матеріалу з врахуванням наноелектромеханічних явищ – в рамках нелокальної теорії Ерінгена. Розглянуто вплив різних параметрів – показника градієнтості, параметрів нелокальності, довжини нанобалки, темпера- тури навколишнього середовища – на коефіцієнт термопружного демпфування. Показано, що термо- пружне демпфування може бути кероване зміною цих параметрів. 1. Lepage S. Stochastic finite element method for the modeling of thermoelastic damping in microresonators, Ph. D. Dissertation, University of Liege, Departmentof Aerospace and Mechanics (2006). 2. Lepage S. Stochastic finite element method for the modeling of thermoelastic damping in micro- resonators, Ph.D. Dissertation, University of Liege, Department of Aerospace and Mechanics, 1-38 (2006). 3. Younis M.I. Modeling and Simulation of Microelectromechanical Systems in Multi-Physics Fields. Proc. 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