Wave propagation in rotating thin‐walled porous blades reinforced with graphene platelets

Abstract

In this study, wave propagation in functionally graded (FG) graphene reinforced porous nanocomposite rotating thin‐walled blades is examined. The porous matrix shows both uniform and nonuniform distribution of graphene platelet alongside the thickness direction. The rule of mixture is used to obtain the effective Young's modulus, based on the Halpin–Tsai micromechanics model along with the mass density as well as Poisson's ratio of the porous blades. Applying the theory of first‐order shear deformation, it is possible to derive the governing motion equations based on Hamilton's principle whose analytical solution results in obtaining wave frequency as well as phase velocity of the rotating thin‐walled porous blades. According to the theory of thin‐walled Timoshenko beam, both lagging and flapping vibration modes have been considered. The impacts of number of layers, graphene platelets together with porous distribution patterns, weight fraction of graphene platelets, geometry of graphene platelets nanofillers as well as porosity coefficient on the wave propagation behaviors of the rotating thin‐walled porous blades are examined for the first time. The results show that the symmetric distribution of porosity with graphene platelets pattern A can predict the highest wave frequency and phase velocity for the composite blades.

Dynamic instability characteristics of graphene‐reinforced cellular sandwich plates using a three‐variable isogeometric approach

“…Nevertheless, the existence of internal pores in cellular materials may significantly decrease their stiffness which can result in some limitations in terms of their practical applications. The addition of reinforcing phases like graphene nanoplatelets (GNPs) [8][9][10][11][12] to cellular materials is a promising solution to deal with this problem since GNPs offer a range of beneficial features and potential uses such as exceptional mechanical properties, a high aspect ratio or low cost. As a result, numerous studies have been conducted on porous structures reinforced with GNPs in the literature [13][14][15][16][17][18].…”