University of TehranJournal of Computational Applied Mechanics2423-671353320220901Exact analytic solution for static bending of 3-D plate under transverse loading3093318783610.22059/jcamech.2022.342953.721ENFestus ChukwudiOnyekaDepartment of Civil Engineering, Edo State University Uzairue, Edo State, 312102, Nigeria0000-0002-2668-9753Thompson EdozieOkekeDepartment of Civil Engineering, University of Nigeria, Nsukka, Enugu State, 410101, Nigeria.Chidobere DNwa-DavidDepartment of Civil Engineering, Michael Okpara University of Agriculture, Umudike, Abia State, 440109, NigeriaBenjamin OMamaDepartment of Civil Engineering, University of Nigeria, Nsukka, Enugu State, 410101, Nigeria.Journal Article20220512In this study, an exact solution for the bending analysis of a three-dimensional (3-D) rectangular plate under transverse loading is presented using fundamentals of elasticity theory. The theoretical model whose formulation is based on static elastic principle considered transverse shear deformation and still obviate the need for shear correction factor effect which is associated to refined plate theory (RPT). As an improvement to RPT, the equations of equilibrium are obtained from elastic principle using 3-D kinematic and constitutive relations which is later converted to energy equation using general variation to get the deflection and rotation relationship. The solution of the equilibrium equation produced an exact trigonometric displacement function which is a product of the coefficient of deflection and shape function of the plate. By minimizing the general energy equation with respect to the coefficients of deflection and shear deformation rotation, a theoretical model for calculating the deflection, moment and stresses of thick rectangular plate are obtained. The comparative analysis between the present results and other theories shows that this 3-D predicts the vertical displacement, moments and the stresses more accurately than previous studies considered in this paper. It was observed that the present theory varied more with those of those of 2-D numeric analysis and 2-D HSDT with about 7.83% and 6.01%. Meanwhile, the recorded percentage differences showed that a derived 2-D HSDT predicted accurately the bending characteristics of the plate with 2.55%, proving that assumed deflection is coarser for the thick plate analysis. It is concluded that unlike an assumed function, a derived 2-D theory can give a close form solution, but a typical 3-D theory of elasticity is required for an exact solution of rectangular plate and can be recommended for the analysis of any type of rectangular plate with such loading and boundary condition.https://jcamech.ut.ac.ir/article_87836_64d0afbdbfa0f3f1a285acb7c737d1a5.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901Assessment of Radial basis function based meshfree method for the buckling analysis of rectangular FGM plate using HSDT and Strong form formulation3323478783710.22059/jcamech.2022.342228.716ENRahulKumarDepartment of Mechanical Engineering, Sardar Vallabhbhai National Institute of Technology, Surat-395007, IndiaMukeshSinghDepartment of Mechanical Engineering, BIT Mesra, off campus, Patna-80014, IndiaChandanKumarInstitute of Business Management, GLA University, Mathura- 281406, IndiaJayDamaniaDepartment of Mechanical Engineering, Sardar Vallabhbhai National Institute of Technology, Surat-395007, IndiaJigyasaSinghDepartment of Mechanical Engineering, MMMUT, Gorakhpur-273010, IndiaJeeootSinghDepartment of Mechanical Engineering, MMMUT, Gorakhpur-273010, IndiaJournal Article20220427An effort has been made in modifying the radial distances of existing radial basis functions (RBFs) for the buckling analysis of functionally graded material (FGM) rectangular plates. The governing differential equations (GDE’s) and boundary conditions are developed by employing the energy principle. The novelty of the present modified RBFs is that they are suitable for analyzing plates with varying aspect ratios. In the present analysis, thirteen different RBFs available in the literature are analyzed. It is found that all RBFs are well suited for buckling analysis of FGM plates with a different aspect ratio which was not possible with existing RBFs. Existing RBFs were suitable for analyzing square plates. To demonstrate the accuracy and efficiency of the present method, results are obtained for the buckling load parameters with modified radial distances for different aspect ratios. The results of several numerical examples have shown that the present modified RBF-based meshfree methods are well suited and accurate for analyzing rectangular plates. The effect of aspect ratio with grading index , span to thickness ratio on the normalized critical buckling load is discussed.https://jcamech.ut.ac.ir/article_87837_dc870415a671b7a8910a80e3c07f2a06.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901Coupled Non-Stationary Thermoelastic Fields In A Rigidly Fixed Round Plate3483558790610.22059/jcamech.2022.342516.718ENZhanslu MKusaevaSamara State Technical University, Office 206, 244 Molodogvardeyskaya str., Samara, 443100, RussiaJournal Article20220503The mathematical formulation of thermoelasticity problems includes coupled non-self-adjoint differential equations of motion and heat conduction. The problem of integrating them and constructing a general solution leads, as a rule, to the study of only the heat conduction equation or to the analysis of thermoelasticity problems in an unconnected formulation. However, for a better assessment of thermomechanical fields, it becomes necessary to construct coupled analytical solutions in a three-dimensional formulation. Therefore, the development of effective analytical methods and algorithms for calculating elastic systems is currently one of the urgent problems of modern science. In this problem, a mathematical calculation model is developed and a closed solution of the coupled axisymmetric non-stationary problem of the theory of thermoelasticity for a rigidly fixed isotropic plate is constructed. Design ratios are obtained by the method of finite biorthogonal transformations and are valid for an external temperature effect arbitrary in time (boundary conditions for thermal conductivity of the 1st kind). Software that allows to analyze the effect of coupled thermoelastic fields on the temperature field and the stress-strain state of the structure has been developed. Numerical analysis of the results shows that for a given external temperature effect, the rigidity of an elastic system (physical and mechanical characteristics and geometric dimensions) has a significant effect on its thermoelastic field. The developed calculation algorithm finds its application in the design of enclosing structures in the form of single-layer and multi-layer plates.https://jcamech.ut.ac.ir/article_87906_20bb0e353365730e436d86881836a013.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901Biomechanical differences between individuals with chronic ankle instability, copers and healthy controls in the countermovement jump on the force plate3563628915310.22059/jcamech.2022.349001.758ENSomayehMohamadiDepartment of Physiotherapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran0000-0003-0291-1257AilinTalimkhaniDepartment of Physiotherapy, Hamadan university of Medical Sciences, Hamadan, IranMozhdehKhaliliDepartment of Physiotherapy, JundiShapour University of Medical Sciences, Ahvaz, IranJournal Article20220921To evaluate the counter-movement jump task in chronic ankle instability (CAI), copers and healthy subjects. Seventy-five subjects (25 CAI, 25 coper and 25 healthy) participated in the present study. Time to stabilization (TTS) and dynamic postural stability index (DPSI) after counter-movement jump-landing task on a force plate in both legs of each participant were assessed. To compare those three groups, One-way Analyses of Variance (ANOVA) with Tukey post hoc test was used. Pair t-test was utilized to demonstrate the probable changes within group. Using one-way Analyses of Variance (ANOVA) with Tukey post hoc testing, the CAI group displayed significant difference in the medial/lateral (ML) TTS and also DPSI in the vertical plane, and in the composite score than the healthy and coper groups. No significant difference was found between dominant and non-dominant legs in each group based on Pair t-test. Significant different dynamic postural stability was demonstrated in CAI group compared with copers and healthy control. It can be suggested that dynamic postural control strategies should be take into account in their rehabilitation programs. No difference between landings on dominant or nondominant leg can suggest central mechanisms for functional ankle instability.https://jcamech.ut.ac.ir/article_89153_0e0e394a6ae9ebda97cf98d27d204682.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901Modeling and Simulations of Multi-dimensional Thermal Behaviours of Plates during Friction Stir Additive Manufacturing3633788810010.22059/jcamech.2022.344235.729ENOlurotimi AdebowaleAdeleyeBiomedical Engineering Dept., University of Lagos, Akoka, Lagos, +234, NigeriaGbeminiyi MusibauSobamowoMechanical Engineering Dept., University of Lagos, Akoka, Lagos, +234, Nigeria0000-0003-2402-1423Journal Article20220609Friction-stir additive manufacturing is a type of solid-state additive manufacturing process that involves intense shear deformation of material during material joining process. The increasing application of the novel technology requires proper understanding of the inherent thermal process. The analysis of the transient thermal behaviour in three dimensions of the welded plates in friction-stir additive manufacturing is studied using Laplace transforms method is presented. It was established from the results that the material reduces in temperature during the simulation process as the distance of the point moving heat source increases from the centerline. Also, the time needed to attain the highest temperature increases with increasing distance between the point moving heat source and the centerline. In addition, the heating and cooling rates decrease while the distance between the point moving heat source and the centerline increases. The peak temperature is approximately 1200oC but this depends on the welding conditions, heat generation the materials. The variation of shoulder heat generation rate with welding rotational speed at different welding velocities of 100-200 mm/min depicts that increasing the tool rotational speed at constant weld speed increases the heat input, whereas the heat input decreases with an increase in the weld speed at constant tool rotational speed. It was also established that the fractional heat generation rate is between 80 to 90% heat is generated at the tool shoulder and the remaining amount at other tool surfaces. However, this depends on the welding conditions. Finally, the temperature profile typical features can be observed from the obtained results at varying monitoring points, and they provide a better analysis of the prevailing factors in the heat flow model for a point moving heat source. Hence, the model and analytical solution provide the benchmark for obtaining temperature profiles for point moving heat source during the additive manufacturing process.https://jcamech.ut.ac.ir/article_88100_d0ff9d51a2314ebdc039f85c8c814356.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901Numerical Simulation of Atmospheric Boundary Layer Over Laboratory Scale Two-Dimensional Hill Using Pressure-Driven Boundary Condition3793928814410.22059/jcamech.2022.343098.723ENRLakshmanNational Institute of Technology Sikkim, Ravangla, Sikkim, India0000-0001-6810-9211RBasakNational Institute of Technology Sikkim, Ravangla, Sikkim, IndiaJournal Article20220515The atmospheric boundary layer (ABL) is the lowest part of the atmosphere directly impacted by the earth's surface. ABL simulation is essential for predicting wind load, pollutant dispersion, and wind capacity over a terrain. ABL can be modeled using the computational fluid dynamics (CFD) tool. Maintaining horizontal homogeneity is critical for a more accurate ABL simulation. Researchers have proposed various boundary conditions for obtaining homogeneously homogeneous ABL. This study investigates pressure-driven boundary conditions for the atmospheric boundary layer over a laboratory-scale two-dimensional (2D) hill. For complex terrains, such as a 2D hill, the numerical analysis of pressure-driven flow has not yet been considered. The validation was done using the experimental results from the ERCOFTAC 69 case, namely a simplified 2D hill. The results are also compared with the shear-driven boundary conditions. The results of simulations of ABL employing pressure-driven boundary conditions using different turbulence models have also been compiled. From MAPE analysis, it is found that the results of ABL simulation using pressure-driven boundary conditions produced lower MAPE values, resulting in superior outcomes compared to the shear-driven boundary conditions.https://jcamech.ut.ac.ir/article_88144_402a720cd8e5a0659225550e36ee3b23.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901Buckling analysis of 2D functionally graded porous beams using novel higher order theory3934138863410.22059/jcamech.2022.345384.736ENChandra Mohana ReddyGMechanical Engineering, School of Technology, GITAM, Hyderabad, 502329, IndiaVenu KumarNathiMechanical Engineering, School of Technology, GITAM, Hyderabad, 502329, IndiaJournal Article20220704Functionally graded material is an in-homogeneous composite, constructed from various phases of material elements, often ceramic and metal and is employed in high-temperature applications. Aim of this work is to examine the behaviour of buckling in porous Functionally Graded Material Beams (FGBs) in 2 directions (2D) with help of fifth order shear deformation theory. With help of potential energy principle and Reddy’s beam theory, equilibrium equations for linear buckling were derived. Boundary conditions such as simply supported – Simply supported (SS), Clamped – clamped (CC) and Clamped-Free (CF) were employed. An unique shear shape function was derived and 5th order theory was adapted to take into account the effect of transverse shear deformation to get the zero shear stress conditions at top and bottom surfaces of the beam. Based on power law, FGB material properties were changed in length and thickness directions. The displacement functions in axial directions were articulated in algebraic polynomials, including admissible functions which were used to fulfil different boundary conditions. Convergence and verification were performed on computed results with results of previous studies. It was found that the results obtained using 5th order theory were in agreement and allows for better buckling analysis for porous material.https://jcamech.ut.ac.ir/article_88634_26693b082599395bee9bb11d319c3972.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901Numerical study of Casson nanofluid over an elongated surface in presence of Joule heating and viscous dissipation: Buongiorno model analysis4144308863510.22059/jcamech.2022.347011.745ENKharabelaSwainDepartment of Mathematics, Gandhi Institute for Technology, Bhubanewar-752054, India0000-0001-5079-2796ManoranjanMishraDepartment of Mathematics, Gandhi Institute for Technology, Bhubanewar-752054, IndiaAbhaKumariDepartment of Mathematics, Nirmala College, Ranchi, Jharkhand-834002, IndiaJournal Article20220810Nanoparticles (NPs) have wide engineering and industrial applications including improving heat transfer, cooling and heating processes, refrigeration, and medical sciences like cancer treatment etc. Further, Buongiorno model is used to determine how Brownian motion and thermophoresis affect the unsteady 2D flow of Casson nanofluid (NF) over a stretching sheet entrenched in a porous medium. The flow is exposed to an exponential heat source, thermal radiation, dissipation, Joule heating, and transverse magnetic field. The diffusion of chemically reactive NPs to base fluid has been considered. The leading equations of flow model admit similarity solution and reduce to non-linear ODEs by appropriate similarity renovations and elucidated numerically by MATLAB software using bvp4c code. It is found that incidence of NPs in the base fluid reduces the shearing stress at the plate surface so as to avoid back flow. Thermophoresis favours the rise in volume fraction and temperature of the nanofluid. Use of high-Prandtl number base fluid and NP of high thermal conductivity could be of practical use to increase the rate of heat transfer and to avoid NP accumulation.https://jcamech.ut.ac.ir/article_88635_c08c74e8bd5c2bcf8641d109cccec4fe.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901A thermo-elastic model with a single relaxation time of an unbounded medium heated by a heat supply and moving vertically4314438863610.22059/jcamech.2022.347114.746ENAhmed E.AbouelregalDepartment of Mathematics, College of Arts and Science, Al-Qurayyat, Jouf University, Kingdom of Saudi Arabia.0000-0003-3363-7924Ohud A.Al-RuwailiDepartment of Mathematics, College of Arts and Science, Al-Qurayyat, Jouf University, Kingdom of Saudi Arabia.Faten A.AlsharariDepartment of Mathematics, College of Arts and Science, Al-Qurayyat, Jouf University, Kingdom of Saudi Arabia.Sarah A.AlsharariDepartment of Mathematics, College of Arts and Science, Al-Qurayyat, Jouf University, Kingdom of Saudi Arabia.Ferial A.AlmwassrDepartment of Mathematics, College of Arts and Science, Al-Qurayyat, Jouf University, Kingdom of Saudi Arabia.AdamZakriaDepartment of Mathematics, College of Arts and Science, Al-Qurayyat, Jouf University, Kingdom of Saudi Arabia.https://orcid.org/00Journal Article20220813The current paper presents a thermoelastic model with a single relaxation time to examine the thermoelastic interaction in an isotropic infinite medium. The unbounded medium is exposed to a thermal shock with varying temperatures due to a vertically moving heat source in a planar region. The basic partial differential equations were solved using the Laplace transform method. Physical fields are studied and compared in terms of how the speed of the heat source, the relaxation time parameter, and the time parameters affect their behavior. Graphical presentations are used to analyze physical field variables like temperature changes, thermal stress and deformation.https://jcamech.ut.ac.ir/article_88636_31ae7beb87503f184fa7f6fbc5f08455.pdfUniversity of TehranJournal of Computational Applied Mechanics2423-671353320220901Monotonous, symmetric, and nonsymmetric patterns of porous core in vibration study of nano-composite sandwich plate bonded by piezoelectric sheets4444778915410.22059/jcamech.2022.345795.739ENM.PakizeDepartment of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran.Z.Khoddami MaraghiFaculty of Engineering, Mahallat Institute of Higher Education, Mahallat, Iran.M.Irani RahaghiDepartment of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran.S.NiknejadDepartment of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran.A.Ghorbanpour AraniDepartment of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran.Institute of Nanoscience & Nanotechnology, University of Kashan, Kashan, Iran.Journal Article20220716This paper deals with the free vibrations of a 5-layer sandwich plate consisting of a sutured porous material core. Two randomly oriented straight single-walled carbon nanotube (CNT) reinforced composites and face sheets manufactured of piezoelectric material that is subjected to an external electric voltage, are placed on a Visco-Pasternak foundation. The relationship between strain and stress in the core is expressed by considering the pore fluid pressure based on the Biot theory, and for pore distribution along the core thickness, three uniform, symmetric and nonsymmetric patterns are considered. A quasi-3D sinusoidal shear deformation theory which that couples the effects of shear strain and normal deformation without the need for any shear correction factor which uses Hamilton’s principle and Navier’s method is used to derive the governing equations of the sandwich structure for the simply supported case. Effects of different parameters on the natural frequencies of the plate are studied including layer thickness ratio, porosity parameter, porosity distribution pattern, pores compressibility, the volume fraction of CNTs and external voltage. The maximum frequency in different modes could be an important design factor that is calculated based on the type of the porosity distribution. Controlling the material properties based on specific needs is the most important advantage of the 5-layer sandwich structure. This paper introduces sandwich panels with porous cores, nanocomposite layers and piezoelectric overlays for the first time which is analyzed to determine system vibration frequencies under external voltage and by changing various parameters with emphasis on different porosity distributions. The frequency of monotonous distribution was 4% higher than symmetric and asymmetric distributions for a constant porosity.https://jcamech.ut.ac.ir/article_89154_e36d0e27176a09339cae157a822a3549.pdf