Forced vibration characteristics of embedded graphene oxide powder reinforced metal foam nanocomposite plate in thermal environment

Abstract Dynamic behavior of a new class of nanocomposites consisted of metal foam as matrix and graphene oxide powders as reinforcement is presented in this study in the framework of forced vibration. Graphene oxide powders are dispersed through the thickness of a plate made from metal foam material according to four various functionally graded patterns on the basis of the Halpin-Tsai micromechanical homogenization method. Also, three kinds of porosity distributions including two symmetric and one uniform patterns are considered for the metal foam matrix. As external effects, the plate is rested on the Winkler-Pasternak substrate and under uniform thermal and transverse dynamic loadings. By an incorporation of the refined higher order plate theory and Hamilton's principle, the governing equations of the dynamically loaded graphene oxide powder reinforced metal foam nanocomposite plate are derived and then solved with Galerkin exact solution method to achieve the resonance frequencies and dynamic deflections of the structure. Moreover, the influence of different boundary conditions is taken into account. The results indicate that the forced vibrational response of the graphene oxide powder strengthened metal foam nanocomposite plate is dramatically dependent on various parameters such as graphene oxide powders' weight fraction, different boundary conditions, various porosity distributions, foundation parameters and temperature change of uniform thermal loading

Forced vibration characteristics of embedded graphene oxide powder reinforced metal foam nanocomposite plate in thermal environment

Dynamic behavior of a new class of nanocomposites consisted of metal foam as matrix and graphene oxide powders as reinforcement is presented in this study in the framework of forced vibration. Graphene oxide powders are dispersed through the thickness of a plate made from metal foam material according to four various functionally graded patterns on the basis of the Halpin-Tsai micromechanical homogenization method. Also, three kinds of porosity distributions including two symmetric and one uniform patterns are considered for the metal foam matrix. As external effects, the plate is rested on the Winkler-Pasternak substrate and under uniform thermal and transverse dynamic loadings. By an incorporation of the refined higher order plate theory and Hamilton's principle, the governing equations of the dynamically loaded graphene oxide powder reinforced metal foam nanocomposite plate are derived and then solved with Galerkin exact solution method to achieve the resonance frequencies and dynamic deflections of the structure. Moreover, the influence of different boundary conditions is taken into account. The results indicate that the forced vibrational response of the graphene oxide powder strengthened metal foam nanocomposite plate is dramatically dependent on various parameters such as graphene oxide powders' weight fraction, different boundary conditions, various porosity distributions, foundation parameters and temperature change of uniform thermal loading.This research is financially supported by the Ministry of Science and Technology of China (Grant No. 2019YFE0112400), National Science Foundation of China (Grant No. 52078310), the Taishan Scholar Priority Discipline Talent Group program funded by the Shan Dong Province, and the first-class discipline project funded by the Education Department of Shandong Province. The publication of this article was funded by Qatar National Library.Scopu

On the dynamics of FG-GPLRC sandwich cylinders based on an unconstrained higher-order theory

In the present paper, a novel unconstrained higher-order theory (UCHOT) is applied to analyse the free vibration of cylindrical sandwich shells with nanocomposite face sheets reinforced with graphene platelets. UCHOT considers the shear and thickness deformations. It is assumed that the cylinder includes a soft core which embedded between functionally graded graphene platelets reinforced composites (FG-GPLRC). FG-GPLRC face sheet consists of several laminas that the GPL weight fraction is modified layer to layer based on the various functionally graded (FG) patterns. The Winkler-Pasternak elastic foundation is located at the inner surface of the shell. Highly coupled motion equations are solved by a semi-analytical approach. This approach is blended of the generalized differential quadrature and trigonometric expansion (TE-GDQ) methods. Solving the obtained eigenvalue problem, corresponding frequencies to the cylindrical sandwich shell are achieved. In the results part, comparison studies are carried out to indicate the validity and performance of the selected theory and solution method. Afterward, some parametric results are demonstrated to investigate the impacts of shell theory order, geometrical parameters, FG model, elastic foundation parameters, and boundary conditions on the frequency response of the mentioned structure

An improved electroporator with continuous liquid flow and double-exponential waveform for liquid food pasteurization

Pulsed electric field (PEF) pasteurisation keeps treated liquid food fresh and nutritious compared to traditional thermal pasteurisation. However, PEF adoption is still limited on an industrial scale due to a lack of practical systems. As a result, a great deal of research has gone into overcoming the limitations of the existing systems. Keeping this in mind, the current study contributes to the improvement of the electroporator. The heterogeneous electric field's distribution raises the temperature of the treated food samples. Liquid laminar flow is a reason for heterogeneous electric field's distribution in continuous treatment. Hotspots may also be created by using an inefficient high-voltage waveform in addition to the heterogeneous electric field distribution. This study rectifies the heterogeneous distribution by proposing an improved coaxial treatment chamber and double-exponential waveform to replace the exponential-decaying waveform. A static mixer provides an increased mixing, i.e. disrupting the laminar flow, inside the treatment zone. COMSOL based computational model was developed to study flow behaviour and corresponding temperature distribution in the proposed coaxial treatment chamber with sieves. Based on the model, it has been concluded that coaxial electrodes with sieves provide more homogeneous flow properties inside the treatment chamber. The effectiveness of the double-exponential (DE) waveform was validated using MATLAB. A three-stage Marx generator giving the DE waveform was designed and constructed. The performance of the improved treatment chamber together with the DE waveform, known as the electroporator, was studied using chemical and microbial analysis. Untreated, PEF treated, and thermal treated orange samples were stored at 4°C for 9 days before being examined. The lowest microbial growth was observed in both the PEF treated with sieves and thermally treated food samples than the untreated sample. However, treated juices' visual and chemical colour analysis showed that the PEF-treated sample acquired a brighter appearance than a thermally processed sample. Thus, this study provides significant findings in developing and utilising an electroporator to inactivate microorganisms

Forced resonance vibration analysis in advanced polymeric nanocomposite plate surrounded by an elastic medium

The resonance phenomenon is a key factor in studying different structures. This research work aim is at reporting a size-dependent model to analyze the forced resonance phenomenon in advanced polymeric composites that are reinforced with single-walled carbon nanotubes (SWCNTs). To reach this aim, third-order shear deformable model in Cartesian coordinate combined with a general nonlocal strain gradient theory is adopted. A virtual work of Hamilton statement is implemented over the aforementioned theories to gain the governing equations as well as boundary conditions. Then, an analytical Navier based technique is applied to solve the problem of getting the resonance position. The numerical examples are devoted to reporting a variety of active parameters such as geometrical conditions, small scale and elastic medium coefficients, as well as CNTs weight fraction and its distribution patterns.This research is financially supported by the Ministry of Science and Technology of China (Grant No. 2019YFE0112400 ), National Science Foundation of China (Grant No. 51678322 ), the Taishan Scholar Priority Discipline Talent Group program funded by the Shan Dong Province, and the first-class discipline project funded by the Education Department of Shandong Province.Scopu

Dispersion of waves characteristics of laminated composite nanoplate

The current work fills a gap of a small-scale study on wave propagation behavior of symmetric, antisymmetric, and quasi-isotropic cross/angle-plies laminated composite nanoplates. The governing equations are derived through the Hamiltonian principle for four-variable refined shear deformation plate theory in conjunction with the assumption of a non-classical theory, and then size-dependent formulations are solved via an analytical solution procedure. This work provides information to accurately analyze the influence of lay-up numbers and sequences, geometry, fiber orientations, and wave numbers on the size-dependent wave propagation response of laminated composite nanoplates.This research is financially supported by the Ministry of Science and Technology of China (Grant No. 2019YFE0112400), National Science Foundation of China (Grant No. 51678322), the Taishan Scholar Priority Discipline Talent Group program funded by the Shan Dong Province, and the first-class discipline project funded by the Education Department of Shandong Province.Scopu

Thermo-mechanical buckling analysis of FG-GNPs reinforced composites sandwich microplates using a trigonometric four-variable shear deformation theory

The current study is aimed to investigate the thermo-mechanical buckling responses of the sandwich microplate with Graphene nanoplatelets (GNPs)-reinforced Epoxy core fully bonded to single-walled carbon nanotubes (SWCNTs)-reinforced piezoelectric patches. The face sheets were exposed to the electric field and the microplate was assumed to locate on the Pasternak elastic substrate. The GNPs and SWCNTs were dispersed throughout the core and face thickness according to some specific functions. To consider the shear deformation effect, tangential shear deformation theory (TSDT), as a trigonometric higher-order theory, was used. The size effects were also included through applying and the modified strain gradient theory (MSGT). The virtual displacement principle was utilized to derive the governing equations and then by employing an analytical method, they were solved. The validity of the results was confirmed by comparing the results for simpler state with previously published ones. A parametric study is provided to observe behavior of the microstructure in different conditions. It was observed that GNPs and CNTs dispersion patterns play an important role in the microplate buckling behavior, as well as temperature variations. The outcomes of this work may help to manufacture more efficient engineering smart structures, such as micro/nanoelectromechanical systems

Wave propagation analysis of porous functionally graded curved beams in the thermal environment

In the present paper, wave propagation behavior of porous temperature-dependent functionally graded curved beams within the thermal environment is analyzed for the first time. A recently-developed method is utilized which considers the reciprocal effect of mass density and Young's modulus in order to explore the influence of porosity. Three different types of temperature variation (uniform temperature change (UTC), linear temperature change (LTC), sinusoidal temperature change (STC)) are employed to study the effect of various thermal loads. Euler-Bernoulli beam theory, also known as classic beam theory is implemented in order to derive kinetic and kinematic relations, and then Hamilton's principle is used to obtain governing equations of porous functionally graded curved beams. The obtained governing equations are analytically solved. Eventually, the influences of various parameters such as wave number, porosity coefficient, various types of temperature change and power index are covered and indicated in a set of illustrations.Scopu

Analysis of Power Law Fluids and the Heat Distribution on a Facing Surface of a Circular Cylinder Embedded in Rectangular Channel Fixed With Screen: A Finite Element’s Analysis

The current article is an understanding of heat transfer and non-Newtonian fluid flow with implications of the power-law fluid on a facing surface of the circular cylinder embedded at the end of the channel containing the screen. The cylinder is fixed with an aspect ratio of 4:1 from height to the radius of the cylinder. The simulation for the fluid flow and heat transfer was obtained with variation of the angle of screen $\frac {\pi }{6}\le \theta \le \frac {\pi }{3}$ , Reynolds number 1000 ≤ Re ≤ 10, 000 and the power-law index $0.7\le n\le 1.3$ by solving two-dimensional incompressible Navier-Stokes equations and the energy equation with screen boundary condition and slip walls. The results will be in a good match with asymptotic solution given in the literature. The results are presented through graph plots for non-dimensional velocity, temperature, mean effective thermal conductivity, heat transfer coefficient, and the local Nusselt number on the front surface of the circular cylinder. It was found that the ratio between the input velocity to the present velocity on the surface of the circular cylinder remains consistent and reaches up to a maximum of 2.2% and the process of heat transfer does not affect by the moving of the screen and clearly with the raise of power-law indexes the distribution of the heat transfer upsurges. On validation with two experimentally derived correlations, it was also found that the results obtained for the shear-thinning fluid are more precise than the numerically calculated results for Newtonian as well as shear-thickening cases. Finally, we suggest necessary measures to enrich the development of convection when observing with strong effects influenced by the screens or screen boundary conditions