Search

This paper conducts modeling and vibration analysis of a spinning cylindrical shell attached with a beam, namely, an assembled cylindrical shell-beam structure, which is reinforced by graphene nanoplatelets (GPLs). The available performance attributes of the beam and cylindrical shell, determined by the Halpin-Tsai model together with the rule of mixture, are deemed to change continuously along their thickness directions. In accordance to the Euler-Bernoulli beam theory and the Donnell's shell theory, the Lagrange's equation is applied to obtain the coupled governing equations of the assembly. Besides, the substructure modal synthesis method is used to acquire vibration behaviors of the nanocomposite assembled shell-beam structure. The influences of the graphene nanoplatelet (GPL) distribution pattern, GPL weight fraction, length-to-width ratio and length-to-thickness ratio of GPLs, and spinning speed on the vibration performance of the assembled shell-beam structure. The findings could provide an important light on the design of coupled nanocomposite cylindrical shell-beam assembly for outstanding mechanical performance. [ABSTRACT FROM AUTHOR]

The size-dependent bending and free vibration of bi-directional functionally graded graphene nanoplatelets reinforced composite (BDFG-GPLRC) microbeams are investigated based on the Timoshenko beam theory and isogeometric analysis (IGA). The modified couple stress theory (MCST) is employed to describe the scale effect of microbeams. GPLs are distributed as power functions along the thickness and axis directions and four types of distribution patterns are taken into account. Employing the minimum potential energy principle and Hamilton's principle, the government equations are established and solved by IGA. Correctness and accuracy of this method are verified by comparing with a published paper. By means of several numerical examples, the effects of GPL weight fraction, power-law indexes, boundary conditions and scale parameter on bending and free vibration behaviors of BDFG-GPLRC microbeams are studied in detail. [ABSTRACT FROM AUTHOR]

The paper investigates nonlinear dynamic behavior of functionally grade graphene nanoplatelets reinforced (FG-GPLRC) shell with radius as a high-order function using the classical thin shell theory (CTST) and the Von Karman-Donnell geometrical nonlinearity assumption. Different from cylindrical or conical shells, variations of radius are formulated as quadratic or/and cubic functions, generating three types of funnel shells. To verify the computation, the fundamental frequencies are compared with the previous literatures and Finite Element Analysis. The effects of various parameters including geometries, materials, temperature are considered. Obtained results of the shell promisingly make a significant contribution to various fields of engineering. [ABSTRACT FROM AUTHOR]

This paper presents the characterisation and for the first time the application of a nanocomposite based on reduced graphene oxide (rGO) modified with antimony nanoparticles (SbNPs) in the stripping analysis of Cd2+, Pb2+, Cu2+ and Hg2+ in natural water samples. The nanocomposite was easily synthesised by a chemical reduction approach using sodium borohydride as the reductant agent. The designed experiment investigated the remarkable rGO electronic properties with the synergetic combination of metallic SbNPs. The results showed that the GC/rGO-SbNPs electrode selective detected the heavy metal ions (HMIs) with suitable sensitivity. Under optimal conditions, the proposed electrode showed a good linear relationship with the concentration of Cd2+, Pb2+, Cu2+ and Hg2+ ranging from 0.1 to 4.5 µmol L−1 with detection limits for simultaneous determination of 45.3, 16.5, 34.1 and 4.8 nmol L−1, respectively. This presented work enables a full understanding of rGO-SbNPs properties in stripping analysis of HMIs, as well as a novel approach for future in situ analysis. [ABSTRACT FROM AUTHOR]

In this paper, a conductive layer is developed by printing a graphene nanoparticles-based conductive ink on the silk fabric showing surface resistance of 2.3 Sand conductivity of Sm, respectively. The printed silk fabric is utilized to fabricatemode wideband antenna for aeronautical radio-navigation applications centered at 4200 MHz. Excellentimpedance bandwidth of 26.4% is obtained by incorporating a patch-ground shorting stub. The antenna has reasonable radiation efficiency above 74% including packaging losses and conical radiation pattern at higher order mode. The simulation and measurements are performed considering practical scenario showing excellent measured results. [ABSTRACT FROM PUBLISHER]