Thermoelastic Damping of Functionally Graded Material Micro-Beam Resonators Based on the Modified Couple Stress Theory  

作　　者：Zhichao Zhang Shirong Liu 

机构地区：[1]School of Civil Engineering and Science,Yangzhou University,Yangzhou 225127,China

出　　处：《Acta Mechanica Solida Sinica》2020年第4期496-507,共12页固体力学学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(No.11672260);the Natural Science Foundation of Jiangsu(No.BK20180894).

摘　　要：Thermoelastic damping(TED)is one of the main internal energy dissipation mechanisms in micro/nano-resonators.Accurate evaluation of TED is important in the design of micro-electromechanical systems and nano-electromechanical systems.In this paper,a theoretical analysis on the TED in functionally graded material(FGM)micro-beam resonators is presented.Equations of motion and the heat conduction equation governing the thermodynamic coupling free vibration of non-homogenous micro-beams are established based on the Euler Bernoulli beam theory associated with the modified couple stress theory.Material properties of the FGM micro-beam are assumed to change in the depth direction as power-law functions.The layer-wise homogenization method is used for solving the heat conduction equation.By using the mathematical similarity of eigenvalue problem between the FGM beam and the reference homogeneous one,the complex natural frequency including TED is expressed in terms of the natural frequency of the isothermal homogenous beam.In the presented numerical results,influences of various characteristic parameters,such as beam thickness,material gradient index,structure size,vibration mode and boundary conditions,on TED are examined in detail.It shows that TED decreases with the increases in the values of length scale parameters because the latter lead to the increase in structural stiffness.

关 键 词：Functionally graded material Size dependent Thermoelastic damping MICRO-BEAM 

分 类 号：O342[理学—固体力学]