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In this paper large deformation of the skew microplate made of laminated composite enhanced with graphene nanosheets is investigated using first shear deformation theory (FSDT) when the plate undergoes combination of mechanical and thermal loads. Halpin-Tsai model is utilised to model mechanical properties while for thermal properties Schapery model is considered. First, shear deformation of the plate was obtained while using Green-Lagrange tensor the non-linear strain of the microplate is extracted using the von-Karman assumptions. Then, by Modified Coupled Stress Theory (MCSD), the components of Cauchy and Couple stress tensors are specified. Finally, using Hamilton Principle the governing equation of the microplate and boundary conditions are computed. After deriving analytical governmental equation results are presented for the simple support boundary condition and the proposed model is validated by previously reported data and it proves to be promising. Primary results showed that with raising skew angle deflection and bending moment decreases which means microplate becomes more rigid in higher skew angles. Higher mechanical loads lead to higher deflections and bending moments. Four different configurations of the layers were analysed from which angle-ply configuration possessed highest deflection and bending while UD configuration revealed the lowest values of deflection and bending moment. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive investigation on the vibrations of reinforced concrete structure by graphene oxide powders (GOPs) using a polynomial displacement field and the Generalized Differential Quadrature Method (GDQM). The study focuses on analyzing the dynamic behavior of the structure and assessing the effects of three different distribution patterns of GOPs on its vibrations. To accurately model the deformation of the pressure vessel, a polynomial displacement field is employed, taking into account the complex geometrical and material properties of the structure. The results highlight the significant influence of the distribution pattern of GOPs on the natural frequencies of the spherical concrete pressure vessel. The analysis reveals that variations in the weight fraction and arrangement of GOPs have a direct impact on the stiffness and dynamic characteristics of the structure. Specifically, increasing the weight fraction of GOPs generally leads to higher natural frequencies, indicating enhanced structural rigidity. Moreover, the polynomial displacement field and GDQM demonstrate their effectiveness in accurately predicting the vibrations of the reinforced pressure vessel. The combination of these numerical techniques enables efficient and reliable analysis of the dynamic response, allowing for optimization of the design and performance of spherical concrete pressure vessels.

Nanofluids show greater heat transfer rate and characteristics of mechanical friction diminution using nano-sized hard elements to fluid. Moreover, regarding the working of heat transfer fluid, nanofluid is widely used in areas of refrigeration, shipping, automobile, chemical industry, energy, electronics, air conditioning, computer, and many other areas to cope heat transference issues. The aforesaid utilizations motivated us to encounter entropy generation aspects for Sutterby nanofluid flow configured by permeable surface. Moreover, well-known Buongiorno's model capturing same attributes of Brownian and thermophoretic-diffusions is presented for modeling and investigation. Additionally, (MHD) as well as thermal radiation effects are the part of current work. Here, we have also considered the viscous dissipation aspects. Similarity variable are used to decrease set of nonlinear PDEs into set of ODEs then resolved numerically by using bvp4c algorithm, besides the pertinent parameters are addressed graphically. The physical aspect of fluid flow, temperature, concentration for variation of involved parameters is explained with the help of graphs. Velocity of Sutterby nano fluid has opposite behaviors versus Sutterby fluid parameter and magnetic parameters. Augmented values of Brownian moment, thermophoresis and heat source parameters intensify the temperature of nanofluid. Concentration of Sutterby nanofluid deteriorates for greater Schmidt number. [ABSTRACT FROM AUTHOR]

In recent decades, there has been a significant rise in the utilization of composite materials for various engineering applications. These advanced materials offer the potential to improve the mechanical properties and vibration characteristics of structural components. This particular study is dedicated to enhancing the vibration performance of coupled curved-curved beams that feature a linear elastic mid-layer, achieved through the incorporation of carbon nanotubes (CNTs), graphene nanoplates (GNPs), and graphene oxide powder (GOPs). The governing equations of the system are solved using the generalized differential quadrature (GDQ) method. While previous research primarily focused on the use of CNTs to enhance the vibration behavior of coupled-curved beams, this study delves into the utilization of multiple nanofillers for this purpose. An essential aspect of modeling composite materials lies in determining their equivalent mechanical properties. This research undertakes a comparison between the rule of mixture (RoM) and Halpin-Tsai methods for calculating these properties, revealing that frequencies derived from the RoM method are higher than those obtained through the Halpin-Tsai approach. Additionally, the study highlights that systems incorporating GNPs demonstrate higher frequencies at lower nanofiller volumes, with CNTs and GOPs following in ranking. However, this hierarchy shifts at higher nanofiller volumes. The arrangement of nanofillers within the system is influenced by its boundary conditions, with the curvature of the bottom beam playing a significant role in affecting vibration behavior. Increasing the radius of the bottom beam (R2) leads to higher system frequencies, which subsequently decrease with higher R2 values.

Purpose: This paper reported the modeling steps of coupled beam nanocomposite system and its fundamental frequency characteristics. The model has been derived for two straight coupled beams (made of carbon nanotube, CNT) as the continuous transitional springs, including a middle elastic layer. Methods: The effective properties of the beam components are evaluated based on the well-known rule of mixture. Additionally, to achieve the generality of the material distribution, various configurations of CNT have been adopted in the current model through the thickness of the structure. The main objective of the present study is to evaluate the effect of material temperature dependency on the frequency parameter of the nanocomposite double beam system. The structural model has been derived mathematically using the robust lower-order theory (first-order shear deformation, FSDT) to compute the eigenvalues without hampering the degree of solution accuracies. The nanotube properties are also considered to be temperature-dependent (TD). The final eigenvalues are computed via a semi-analytical approach, namely generalized differential quadrature (GDQ) approach. Results: First, the natural frequencies of homogenous beam system are compared with the results of frequency parameter available in the literature. Then, the fundamental frequencies of the coupled beam system have been computed analytically for different structural input parameters (material properties, end constraints of full structure and middle elastic layer) to showcase the effect individual and/or combined conditions with and without the influence of temperature. Conclusion: The final outcomes are revealed in detail for different input parameters and the subsequent outcomes. [ABSTRACT FROM AUTHOR]

The present research proposes an applicable and impressive analytical model of Aircraft Engine Cowl (AEC) due to auspicate its frequency parameter. For the first time, the authors configured the structure of AEC by joining two well-known shapes of shell, including elliptical and conical. This procedure is implemented by obtaining the governing motion organization of differential equations affiliated with the Joined Elliptical-Conical Shells (JECS) in line with first-order shear deformation theory (FSDT) and General Shell Formulation (GSF). Moreover, Functionally Graded Materials (FGMs) with various spreading forms along the structure's thickness are used to enhance the dynamic performance of AEC. It is worth mentioning that the recognized Rule of Mixture (RM) is engaged for achieving the equivalent mechanical characteristics of FGM. Finally, a well-known semi-analytical Generalized Differential Quadrature (GDQ) procedure is hired to extract the resulting system of motion equations to access the free vibration responses of AEC with diverse Boundary Conditions (BCs). It is worth mentioning that an applicable and interesting numerical model is done to inspect the remnants of geometric and material features on the oscillation demeanor of AEC structures. It will be verified that the projected procedure can be helpful for AEC's vibration analysis and extendable for other types of studies to predict the AEC structure's static and dynamic treatment. [ABSTRACT FROM AUTHOR]

The nonlinear frequency response of bi-directional functionally graded porous beams experienced range of various end conditions is investigated in this work. The end conditions which are simply supported, clamped-simply supported, clamped-clamped, and clamped-free are taken by using the Von Karman geometric nonlinearity, Green's tensor and Reddy third-order shear deformation theory. A generalized differential quadrature technique (GDQM) accompanied by direct numerical iterance approach is proposed to solve equations. The findings are presented to aid in future research into the effects of various gradient indices, vibration amplitude ratios, porosity coefficients, shear and elastic substrate parameters, boundary conditions, and vibration frequencies on the bi-directional functionally graded beams. The outcomes of this research have practical applications and can be utilized to enhance the design of bi-directional beams. The results are also highly useful in anticipating and identifying potential causes of failure in these beams.

In this research, frequency and resonance area information of a size-dependent electro-elastic rotary non-classical piezoelectric microdisk via modified couple stress theory (MCST) is presented. The computational formulation of the electrically microdisk, non-classical governing equations of electrically annular microdisk are derived by adding the symmetric rotation gradient and higher-order stress tensors to the strain energy. The current non-classical approach is capable for capturing the size-dependency in the electrically annular microdisk by using single material length scale factor. Finally, the non-classical governing equations are solved using generalized differential quadrature method (GDQM). Afterward, a parametric study is carried out to investigate the effects of applied ampere, length scale factor, applied voltage, and radius ratio on the resonance area and frequency responses of the electrically microdisk by considering MCST. The meaningful of resonance area in the current research is that, all designers should have attention to the lower values of natural frequency for obtaining the accurate results. Afterward, a parametric study is done to present the impacts of the radius ratio, length scale parameter, circumferential and radial mode number, geometry of piezoelectric material, applied voltage, and boundary conditions on the frequency responses of the piezoelectric microdisk by considering MCST. The results show that, when the foundation is considered, the effect of the radius ratio on the critical voltage of a piezoelectric microdisk reduces. [ABSTRACT FROM AUTHOR]

In this study, for the first time, free and forced vibrational responses of a unimorph nanobeam consisting of a functionally graded base, along with a dielectric layer of both piezoelectricity and flexoelectricity, is investigated based on paradox-free local/nonlocal elasticity. The formulation and boundary conditions are attained by utilizing the energy method Hamilton's principle. In order to set a comparison, the formulation of a model in the framework of differential nonlocal is first presented. An effective implementation of the generalized differential quadrature method (GDQM) is then utilized to solve higher-order partial differential equations. This method can be utilized to solve the complex equations whose analytic results are quite difficult to obtain. Lastly, the impact of various parameters is studied to characterize the vibrational behavior of the system. Additionally, the major impact of flexoelectricity compared to piezoelectricity on a small scale is exhibited. The results show that small-scale flexoelectricity, rather than piezoelectricity, is dominant in electromechanical coupling. One of the results that can be mentioned is that the beams with higher nonlocality have the higher voltage and displacement under the same excitation amplitude. The findings can be helpful for further theoretical as well as experimental studies in which dielectric material is used in smart structures. [ABSTRACT FROM AUTHOR]

This paper concentrates on axisymmetric free vibration of functionally graded (FG) sandwich annular plates obtained using a quasi-3D plate theory. Motion equations and corresponding boundary conditions are established via the mentioned plate theory which takes into consideration the non-uniform shear strains across the thickness and also stretching trough the thickness. Generalized differential quadrature method (GDQM) is applied to discrete the annular sandwich plate governing equations. The results of this study are applicable for optional thick plates since the adopted theory considers the shear and normal strains across the thickness direction. Outcoming results are verified on the basis of information accessible in the open literature. To investigate the influences of power law index of functionally graded materials (FGMs) and dimensions of the sandwich annular plate layers, parametric studies are presented. It was well demonstrated that the applied theory precisely predicts the natural frequencies of FG annular sandwich plates with arbitrary thickness. [ABSTRACT FROM AUTHOR]

Structures in honeycomb shapes have the configuration of a honeycomb to minimize material usage and to reach minimal cost of material and optimized weight. Thereby, this paper investigates the vibrations of sandwich disk which has imperfect honeycomb core with face sheets of graphene nano-platelets reinforced composite (GPLRC). The core of honeycomb is manufactured of aluminum based on to its high stiffness and low density. In order to have an efficient material constant for the layers of composite, this paper considers the modified Halpin–Tsai theory and the mixture rule. The structure's governing equations of motion are extracted and solved using the Hamilton's principle and generalized differential quadrature method (GDQM), respectively. Then, in order to present the impacts of the patterns of FG, the GPLs' weight fraction, thickness ratio of FG face sheet, GPLs' thickness to length ratio, external to internal radius ratio, the honeycomb core's thickness to internal radius ratio, the compressive and tensile external load on the sandwich disk's frequency with FG-GPLRC face sheet and honeycomb core under a uniform pressure, a parametric research study has been carried out. The results show that the lowest and highest frequency is for FG-O and FG-X patterns, respectively. Another consequence is that the when GPLs are wider, the frequency is much higher, particularly at the initial lGPL/tGPL [ABSTRACT FROM AUTHOR]

This study is appointed to discover the dynamic behavior related to one of the most applicable systems used in engineering, namely coupled beam bridge system. For this reason, the system, which is constructed by two circular arch beams and an elastic layer between them, is vibrationally investigated here. In addition, the geometrical strategy is hired to modify the essential position associated with the situation of the two beams lying on each other. Moreover, the first-order shear deformation theory (FSDT) and the cylindrical panel scheme are employed to discover the fundamental features of the relationships linked to the system. Moreover, by engaging Hamilton's principle and part-by-part integration (or Green–Gauss theory), the governing equations related to the motion of the system are achieved. Furthermore, the robust semi-analytical technique, renowned by the generalized differential quadrature operator is executed to split up the motion equations linked to the system. Additionally, to confirm the offered configuration, some benchmarks are chosen and solved. Finally, the influence of the diverse boundary conditions, geometrical characteristics, and different values related to the elastic mid-layer stiffness on the natural frequencies of the coupled circular arch–arch beam bridge system are determined. [ABSTRACT FROM AUTHOR]

This study investigates the axisymmetric postbuckling of functionally graded graphene platelets reinforced composite (FG-GPLRC) annular plates resting on nonlinear elastic medium in thermal environment. Five kinds of graphene platelets (GPLs) distribution patterns including U -pattern, X -pattern, O -pattern, A -pattern, and V -pattern have been considered. The nonlinear equilibrium equations and associated boundary conditions are obtained based upon the Mindlin plate theory. The governing equations are solved via the generalized differential quadrature method (GDQM). Afterwards, the direct iterative method is implemented to accomplish postbuckling loads using the buckling mode deflection. In order to confirm the accuracy of the present model, comparisons between our data with those published in the available literature are put forth. Eventually, this paper emphasizes the impact of diverse parameters such as geometrical parameters of the structure, GPLs patterns and their geometric, GPLs weight fraction, boundary conditions, elastic medium's parameters and temperature change on the buckling and postbuckling response of nanocomposite annular plates. It can be found that elastic medium overshadows the applicability of distribution patterns and weight fraction of GPLs. [ABSTRACT FROM AUTHOR]

In this article, frequency analysis of multi-sized hybrid nano-composites (MHC) disk (MHCD) resting on elastic media and located in an environment with gradually changed temperature feature is presented. Carbon fibers (CF) or carbon nanotubes (CNTs) in the macro or nano sizes respectively are responsible for reinforcing the matrix. For prediction of the efficiency of the properties MHCD's modified Halpin-Tsai theory has been presented. The strain-displacement relation in multi-sized laminated disk's dynamics through applying third-order-shear-deformation-theory is determined. The energy methods called Hamilton's principle is applied for deriving the motion equations along with boundary conditions, which has ultimately been solved using generalized differential quadrature method. The deflection as the function of time can be solved by the fourth-order Runge-Kutta numerical method. At the final stage, the outcomes illustrate that patterns of FG, fibers' various directions, the WCNT and VF factors, top surface's applied temperature have considerable impact on the MHCD's dynamics. Another important consequence is that MHC structure with FG-A and UD patterns have a similar effect on the dimensionless natural frequency of the GPLRC disk, while FG-X has the lowest stability and natural frequency. A useful suggestion is that increasing the value of the length to thickness ratio of MHC not only decreases the central deflection of the structure through time but also causes to decrease real-time domain changes for the MHC viscoelastic annular plate. Numerical results declare that viscoelastic disks fabricated from the hybrid nanocomposites can endure higher frequencies compared with those consisted of conventional composites. [ABSTRACT FROM AUTHOR]

This paper provides a general formularization of the nonlocal Euler–Bernoulli nanobeam model for a bending examination of the symmetric and asymmetric cross-sectional area of a nanobeam resting over two linear elastic foundations under the effects of different forces, such as axial and shear forces, by considering various boundary conditions' effects. The governing formulations are determined numerically by the Generalized Differential Quadrature Method (GDQM). A deep search is used to analyze parameters—such as the nonlocal (scaling effect) parameter, nonuniformity of area, the presence of two linear elastic foundations (Winkler–Pasternak elastic foundations), axial force, and the distributed load on the nanobeam's deflection—with three different types of supports. The significant deductions can be abbreviated as follows: It was found that the nondimensional deflection of the nanobeam was fine while decreasing the scaling effect parameter of the nanobeams. Moreover, when the nanobeam is not resting on any elastic foundations, the nondimensional deflection increases when increasing the scaling effect parameter. Conversely, when the nanobeam is resting on an elastic foundation, the nondimensional deflection of the nanobeam decreases as the scaling effect parameter is increased. In addition, when the cross-sectional area of the nanobeam varies parabolically, the nondimensional deflection of the nonuniform nanobeam decreases in comparison to when the cross-sectional area varies linearly. [ABSTRACT FROM AUTHOR]

Due to the remarkable progress in the field of the manufacturing process, smart composites have become the desired target for high-tech engineering applications. Accordingly, for the first time, thermal buckling, critical voltage and vibration response of a thermally affected graphene nanoplatelet reinforced composite (GPLRC) microdisk in the thermal environment are explored with the aid of generalized differential quadrature method (GDQM). Also, the current microstructure is coupled with a piezoelectric actuator (PIAC). The extended form of Halpin-Tsai micromechanics is used to acquire the elasticity of the structure, whereas, the variation of thermal expansion, Poisson's ratio, and density through the thickness direction is determined by the rule of mixtures. Hamilton's principle is implemented to establish governing equations and boundary conditions of the GPLRC microdisk joint with a PIAC. The compatibility conditions are satisfied by taking perfect bonding between the core and PIAC into consideration. Maxwell's equation is employed to capture the piezoelectricity effects. The numerical results revealed the important role of distribution patterns and weight fraction of GPL ( g GPL ), non-dimensional piezoelectric thickness (hp/h), outer to the inner ratio of the radius ( R o / R i ) and applied voltage on the frequency behavior, critical voltage and thermal buckling of the system. Another valuable consequence is that the influence of the h p parameter is hardly dependent on the value of the temperature changes ( Δ T). The favorable suggestion of this survey is that for optimized designing of the GPLRC microsized circular plate should pay special attention to pattern 3 of the GPLs, because in this pattern by increasing the g GPL parameter the critical voltage of the structure increases but for other patterns of GPL, this phenomenon is inverse. [ABSTRACT FROM AUTHOR]

In this study, a cylindrical microshell stability reinforced by graphene nanoplatelets is investigated while an axial load is applied uniformly. In addition, viscoelastic foundation covers the composite nanostructure. Therefore, the impacts of the small scale parameter are studied while nonlocal strain gradient theory (NSGT) is considered. The present research deals for the first time with the consideration of viscoelastic, strain–stress size-dependent parameters along with taking into account of various boundary conditions (BCs), especially C-F ones put into effect on the proposed theory. The governing equations (G.Eqs) and BCs have been obtained utilizing energy method and solved with assistance of the generalized differential quadrature method (GDQM). Besides, for the validation of the results, the results of the current model are compared to the results acquired from analytical method. The results show that, viscoelastic foundation, patterns of GPL distribution, nonlocal parameter, length scale parameter, layers' numbers, boundary condition as well as GPL weight function have considerable impact on the stability of the GPLRC cylindrical microshell. Another significant result is that; for C-F B.Cs, at the higher value of the l / R parameter, the influence of the g GPL on the dimensionless buckling load of the structure is much more remarkable in comparison with the lower one which in results section is investigated in detail. The results of the present investigation would be informative for design and fabrication of the microactuators and microsensors. [ABSTRACT FROM AUTHOR]

The stability analysis of cantilevered curved microtubules in axons regarding various size elements and using the generalized differential quadrature method for solving equations is reported. The impacts of covering MAP Tau proteins along with cytoplasm are taken into account as the elastic medium. Curved cylindrical nanoshell considering thick wall is used to model the microtubules. The factor of length scale (l/R = 0.2) used in modified couple stress theory would result in more accuracy when it comes to comparison with experiments, while alternative theories presented in this paper provide less precise outcomes. Due to the reported precise results, at the lower value of the time-dependent viscoelastic factor ( τ s) by rising the size-dependent factor, the frequency response of the cantilever microtubule increases and this relation between the size-dependent parameter and the structure's natural frequency is changed from direct to indirect for the higher amount of the time-based viscoelastic factor that scientists should attend to this matter when it comes to the microtubule. Furthermore, physical neighboring situations in a cell will be prominent in microtubules' dynamic stability responses, such as membrane and cell-matrix. Since microtubules are likely to be applied as biosensors, this feature could be employed to disclose virulent tumors. [ABSTRACT FROM AUTHOR]

In this research, electrically characteristics of a graphene nanoplatelet (GPL)-reinforced composite (GPLRC) microdisk are explored using generalized differential quadrature method. Also, the current microstructure is coupled with a piezoelectric actuator (PIAC). The extended form of Halpin–Tsai micromechanics is used to acquire the elasticity of the structure, whereas the variation of thermal expansion, Poisson's ratio, and density through the thickness direction is determined by the rule of mixtures. Hamilton's principle is implemented to establish governing equations and associated boundary conditions of the GPLRC microdisk joint with PIAC. The compatibility conditions are satisfied by taking perfect bonding between the core and PIAC into consideration. Maxwell's equation is employed to capture the piezoelectricity effects. The numerical results revealed the important role of ratios of length scale and nonlocal to thickness, outer-to-inner ratio of radius ( R o / R i ), ratio of piezoelectric to core thickness (hp/h), and GPL weight fraction ( g GPL ) on the critical voltage of the system. Another important consequence is that by increasing R o / R i , the critical voltage of the smart structure increases more intensely in comparison with the g GPL . [ABSTRACT FROM AUTHOR]

Due to the rapid development of process manufacturing, composite materials with graphene-reinforcement have obtained commercially notices in promoted engineering applications. For this regard, vibrational characteristics of a cylindrical nanoshell reinforced by graphene nanoplatelets (GPL) and coupled with piezoelectric actuator (PIAC) is investigated. Also, the nanostructure is embedded in a viscoelastic medium. The material properties of piece-wise graphene-reinforced composite (GPLRC) are assumed to be graded in the thickness direction of a cylindrical nanoshell and estimated through a nanomechanical model. For the first time in the current study is considering the effects of piezoelectric layer, viscoelastic foundation, GPLRC, and size-effects on the frequency responses of the GPLRC cylindrical nanoshell coupled with PIAC and by assuming perfect bonding between the core (GPLRC cylindrical shell) and the piezoelectric layer. The governing equations and boundary conditions have been developed using minimum potential energy and solved with the aid of the generalized differential quadrature method. In addition, because of piezoelectric layer, Maxwell's equation is derived. The results show that viscoelastic foundation, piezoelectric layer, GPL distribution pattern, length scale parameter and GPL weight function have important role in the frequency characteristics of the GPLRC cylindrical nanoshell coupled with PIAC and surrounded by viscoelastic foundation. The results of the current study are useful suggestions for design of materials science, micro-electro-mechanical systems, and nanoelectromechanical systems such as nanoactuators and nanosensors. Communicated by Francesco Tornabene. [ABSTRACT FROM AUTHOR]

This paper provides a general formularization of the nonlocal Euler–Bernoulli nanobeam model for a bending examination of the symmetric and asymmetric cross-sectional area of a nanobeam resting over two linear elastic foundations under the effects of different forces, such as axial and shear forces, by considering various boundary conditions’ effects. The governing formulations are determined numerically by the Generalized Differential Quadrature Method (GDQM). A deep search is used to analyze parameters—such as the nonlocal (scaling effect) parameter, nonuniformity of area, the presence of two linear elastic foundations (Winkler–Pasternak elastic foundations), axial force, and the distributed load on the nanobeam’s deflection—with three different types of supports. The significant deductions can be abbreviated as follows: It was found that the nondimensional deflection of the nanobeam was fine while decreasing the scaling effect parameter of the nanobeams. Moreover, when the nanobeam is not resting on any elastic foundations, the nondimensional deflection increases when increasing the scaling effect parameter. Conversely, when the nanobeam is resting on an elastic foundation, the nondimensional deflection of the nanobeam decreases as the scaling effect parameter is increased. In addition, when the cross-sectional area of the nanobeam varies parabolically, the nondimensional deflection of the nonuniform nanobeam decreases in comparison to when the cross-sectional area varies linearly.

• Comprehensive vibrational analysis of anti-symmetric laminated composite plates. • Vibrational analysis includes an elastic foundation and thermal effects. • HSDT is applied to estimate the effects of the higher-order transverse shear. • Effects of damping, elastic, aspect and slenderness ratios are discussed in detail. • Different anti-symmetric laminates and boundary conditions are considered. In this work, a comprehensive vibrational behavior analysis is performed on anti-symmetric laminated composite plates resting on visco-elastic foundations undergoing thermal effects. Here, the governing equations of motion are developed through Hamilton's principle and Reddy's plate theory as higher-order shear deformation theory (HSDT) is employed to capture high accuracy. Also, the generalized differential quadrature method (GDQM) is used to predict the vibration response and the natural frequencies. The effects of temperature change, Winkler-Pasternak and damping coefficients for the elastic foundation, the elastic ratio, the arrangement of different anti-symmetric laminates, and the aspect and slenderness ratios are observed and discussed in detail. The results are extracted for fully clamped boundary conditions and the effects of other boundary conditions are also illustrated. [ABSTRACT FROM AUTHOR]

A curved pipe bent in the arc of a circle conveying fluid is investigated. The flowing fluid is considered as a non-compressible and heavy. The considered pipe is assumed hinged at its both ends. The Generalized Differential Quadrature Method is employed to investigate the dynamic stability of the pipe. The obtained numerical results show the dependence of the critical fluid velocity on the maximal central angle of the pipe. [ABSTRACT FROM AUTHOR]

Summary: The thermal management system of a Lithium‐ion battery consisting of phase‐change material (PCM) is considered in this study. The batteries are covered by a large volume of PCM. A 18650 battery is used in this numerical investigation as a case study and all achievements are implemented on it. The battery thermal management system (BTMS) parameters during discharge‐rest‐charge‐rest cycles are concerned to understand PCM behavior and battery resilience in the long run. The battery is placed adjacent to various PCMs and is charged and discharged at different rates. Results show that the paraffin wax has the worst performance, and hydrate salt and capric acid have the best performance. Furthermore, the use of polyethylene glycol as PCM improves the performance of the BTMS. Meanwhile, the composite of nano‐graphite and PCM would increase a reasonable effect on the BTMS functionality. [ABSTRACT FROM AUTHOR]

A curved pipe bent in the arc of a circle conveying fluid is investigated. The flowing fluid is considered as a non-compressible and heavy. The considered pipe is assumed cantilevered at its both ends. The Generalized Differential Quadrature Method is employed to investigate the dynamic out off plane stability of the pipe. The obtained numerical results show the dependence of the critical fluid velocity on the maximal central angle of the pipe. [ABSTRACT FROM AUTHOR]

• Comprehensive study of localized cooling loads on thermoelastic response of plates. • Even minor localized thermal loads can generate substantial stress and deflection. • Thermal loading/unloading rapidity times are analyzed for localized thermal loads. • Thermal load duration and load magnitude have significant effect on the response. In this study, for the first time, localized thermal cooling is considered for the transient thermoelastic response of an axisymmetric plate, addressing the underexplored area of localized low-temperature thermoelasticity. Functionally graded composite plates are analyzed which consist of a mixture of stainless steel (S U S 304) and low-carbon steel (A I S I 1020). A two-dimensional transient heat conduction equation is employed to capture localized cooling effects, featuring various adaptive time-dependent thermal boundary conditions which mirror both loading and unloading scenarios, effectively simulating real-world phenomena. Novel parameters are introduced to facilitate a comprehensive understanding of various aspects of thermal load handling and their impact on thermoelastic responses. The heat conduction equations are solved using the Generalized Differential Quadrature Method (GDQM) and the Crank-Nicolson scheme. The nonlinear governing equations, incorporating geometrical nonlinearity through the von Kármán assumption within the First Shear Deformation Theory (FSDT) framework, are solved using the GDQM and the Picard's technique. The model is validated using Finite Element Method (FEM) through Abaqus. A comprehensive analysis is provided that considers influence of the ratio of thermally affected and unaffected plate surface, thermal load magnitude, rapidity of thermal loading and unloading, duration of the cooling load, geometrical nonlinearity, and temperature dependence of material. The study shows that the maximum von Mises stress within the structure remains consistent regardless of the duration of the cooling load, as long as the rate at which the cooling load is applied stays the same. Additionally, the findings reveal that even minor localized thermal loads can produce substantial stress, especially at the intersection of thermally affected and non-affected zones on the exposed surface in some situations. [ABSTRACT FROM AUTHOR]

In this article, the vibrational analysis of temperature-dependent cylindrical functionally graded (FG) microshells surrounded by viscoelastic a foundation is investigated by means of the modified couple stress theory (MCST). MCST is applied to this model to be productive in design and analysis of micro actuators and micro sensors. The modeled cylindrical FG microshell, its equations of motion and boundary conditions are derived by Hamilton’s principle and the first-order shear deformation theory (FSDT). For the first time, in the present study, functionally graded length scale parameter which changes along the thickness has been considered in the temperature-dependent cylindrical FG microshell. The accuracy of the present model is verified with previous studies and also with those obtained by analytical Navier method. The novelty of the current study is consideration of viscoelastic foundation, various thermal loadings and size effect as well as satisfying various boundary conditions implemented on the temperature-dependent cylindrical FG microshell using MCST. Generalized differential quadrature method (GDQM) is applied to discretize the equations of motion. Then, some factors are investigated such as the influence of length to radius ratio, damping, Winkler and Pasternak foundations, different temperature changes, circumferential wave numbers, and boundary conditions on natural frequency of the cylindrical FG microshell. The results have many applications such as modeling of microrobots and biomedical microsystems.

In this research, the dynamic instabilities of nanocomposite truncated conical shells containing a quiescent or a flowing inviscid fluid are scrutinized. Nonlinear dynamic equations are established according to the Novozhilov nonlinear shell theory along with Green's strains and Hamilton principle. The velocity potential and Bernoulli's equations are adopted to calculate fluid pressure acting on the conical shell. The nonlinear governing equations are discretized using trigonometric expansion through the circumferential direction and generalized differential quadrature method (GDQM) through the meridional direction. A detailed parametric study is directed to provide an insight into the influence of volume fraction of carbon nanotubes (CNTs), CNT dispersion, geometrical parameters, and boundary conditions on the divergence and flutter instabilities of nanocomposite truncated conical shells. This study shows the superb efficiency of the outlined solution procedure in reducing computational costs and virtual storage. The simulation indicates that the beginning of divergence and flutter instabilities can be significantly postponed by selecting an appropriate dispersion of CNTs through the thickness of the conical shell. Furthermore, the onset of flutter and divergence instabilities are found to be very sensitive to the semi-vertex angle and thickness-to-radius ratio. The results of this research shed light into using ultra-high-strength and low-weight nanocomposite for pressure vessels applications. • Investigating the effectiveness of CNT in postponing the onset of flutter instability. • Examining the efficiency of CNT in postponing the onset of divergence instability. • Finding the best and worst distributions of CNTs in improving dynamic stability boundaries. • Proposed an efficient solver for the fully coupled solution of fluid–structure interaction problems. [ABSTRACT FROM AUTHOR]