چكيده به لاتين
Graphene is a two-dimensional nanoparticle composed of carbon atoms and widely used in nanoscale structures due to its unique properties. Graphene is synthesized either single-layer or multi-layer. Between the graphene layers, there are van der waals bonds that are very weak compared to covalent bonds. The presence of these weak links may change the properties of multi-layer graphene compared to single-layer graphene. Depending on the relative motion of the graphene layers on each other, the van der waals bonds can have tensile, compressive, or shear effects. The study of vibrational behavior of single-layer and multi-layer graphene with regard to tensile, compressive and shear effects have been reported separately in several references. An overview of the references shows that so far the shear effect of nanoribbon and multi-layer graphene has been investigated by the sandwich theory of irregularity in which each nanoribbon layer is modeled on the theory of Euler-Bernoulli beam and each graphene layer based on the theory of Classical pages. And a nonlocal parameter is proposed based on this type of theory.
The purpose of this thesis is to investigate the shear effects on the vibrational behavior of multi-layer graphene, since the shear effect on low frequencies and tensile-compression effects is effective at high frequencies (greater than 20 frequencies). Since, in the design of graphene-based electromechanical systems, it is important to consider low frequencies in comparison with the frequencies greater than twenty, so the purpose of this study is to investigate the shear effect between layers on Free vibrations of multilayer graphene plates. For this purpose, multi-layer graphene plates are considered as a homogeneous sheet and are modeled based on nonlinear theories of Mindelin and Reddy. The shear effect between the layers resulting from the van der Waals bonds is considered to be the shear modulus in the mentioned theory. Due to the special applications of the Cantilever boundary conditions, this kind of boundary condition is investigated and natural frequencies are extracted using a harmonic differential quadrature method.
