Article
Computer Science, Interdisciplinary Applications
Toan Minh Le, Duy Vo, Zwe Yan Aung, Elena Atroshchenko, Tinh Quoc Bui, Jaroon Rungamornrat
Summary: This paper proposes a general strain-gradient and shear-deformable isogeometric microshell formulation,which can accurately simulate the size-dependent behaviors of thin to moderately thick in-plane functionally graded (IFG) microshell structures. It can also effectively provide the predictions of different reduced strain-gradient based theories. The presented formulation is expected to serve as a comprehensive and reliable instrument to assist the design of advanced thin-walled components.
ENGINEERING WITH COMPUTERS
(2023)
Article
Mathematics
Bekir Akgoz, Omer Civalek
Summary: This study analyzes the buckling problem of nonhomogeneous microbeams with a variable cross-section. The influences of size effect, changes in the cross-section and Young's modulus, size dependency, and non-classical boundary conditions on buckling loads are examined.
Article
Engineering, Mechanical
Vahid Movahedfar, Mohammad M. Kheirikhah, Younes Mohammadi, Farzad Ebrahimi
Summary: This research conducted nonlinear vibration analysis of a functionally graded piezoelectric doubly curved microshell in thermal environment based on modified strain gradient theory. By incorporating three scale parameters and a power-law model, the effects of material gradation and temperature changes on vibration frequency were considered. The obtained results indicated the relevance of calculated frequencies to scale parameters, material gradation, electrical voltage, curvature radius, and temperature changes.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Civil
Ehsan Heydari, Ali Mokhtarian, Mostafa Pirmoradian, Mohammad Hashemian, Alireza Seifzadeh
Summary: Wave propagation in air-filled double-walled functionally graded cylindrical microshells subjected to linear and non-linear thermal loadings was investigated using modified strain gradient theory (MSGT) and first-order shear deformation assumption (FSDA) framework. The study revealed the influence of size effects and material characteristics distribution on the Sound Transmission Loss (STL) through double-walled FG cylindrical microshells. The accuracy of the developed solution was examined by comparing it to data from previous studies, showing the impacts of temperature distribution, functionally graded index, incident angles, acoustic cavity depth, and length scale parameter on STL.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Multidisciplinary
Yuan Tang, Hai Qing
Summary: This work investigates the elastic buckling and free vibration response of functionally graded Timoshenko beams using a nonlocal strain gradient integral model. By deriving governing equations and boundary conditions via Hamilton's principle and utilizing Laplace transform technique to solve integral-differential equations, explicit expressions for bending deflections, moments, cross-sectional rotation, and shear force are obtained with eight unknown constants. The nonlinear characteristic equations for determining buckling load and vibration frequency are explicitly derived, and the results are validated against existing literature.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Physics, Multidisciplinary
Fei Zhang, Chun Yu Bai, Yang Zhang, Dong Yu Cao
Summary: The study examines the dynamic stability of microshells made of FG 3D-GrFs using theoretical methods and identifies significant effects of different parameters on the stability characteristics of the microshells.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Chemistry, Multidisciplinary
Feixiang Tang, Fang Dong, Yuzheng Guo, Shaonan Shi, Jize Jiang, Sheng Liu
Summary: This study investigates the buckling and post-buckling problems of size-dependent functionally graded material thin plates using the framework of the Modified Couple Stress Theory. By considering the power-law distribution with scale effects, the post-buckling deflection and critical buckling load of the plates are derived. It is found that the power-law index parameters have a significant influence on the critical buckling displacement, load, and strain energy, while the scale effect parameter has a greater impact. Additionally, the results show that the scale effects increase material stiffness and that the power-law index parameters affect FGM properties.
Article
Mathematics, Applied
Pham Toan Thang, T. Nguyen-Thoi, Jaehong Lee
Summary: The main goal of this research paper is to model and analyze bidirectional functionally graded nanobeams using the Timoshenko beam theory and nonlocal strain gradient theory. The study focuses on understanding mechanical behavior, calculating important parameters, and formulating equilibrium and stability equations for a detailed investigation. Specific examples are presented to verify the proposed solution, and the influences of material properties and nonlocal parameter on critical buckling load and transverse deflection are examined.
APPLIED MATHEMATICS AND COMPUTATION
(2021)
Article
Mechanics
Jun Hong, Shaopeng Wang, Gongye Zhang, Changwen Mi
Summary: A new functionally graded non-classical Timoshenko microbeam model has been developed, incorporating strain gradient, couple stress, and velocity gradient effects to explain power-law variation in two-phase materials. The model demonstrates significant differences from classic models when the FGM beam thickness is very small, but these differences diminish as thickness increases.
INTERNATIONAL JOURNAL OF APPLIED MECHANICS
(2021)
Article
Engineering, Civil
H. N. Li, W. Wang, S. K. Lai, L. Q. Yao, C. Li
Summary: This paper investigates the nonlinear vibration and stability analysis of rotating functionally graded (FG) piezoelectric nanobeams using the nonlocal strain gradient theory. The study derives nonlinear equations of motion and discretizes them to determine the vibration frequencies and buckling loads of the nanobeams. The results show that increasing the nonlocal parameter and material length parameter can result in a stiffness-hardening effect, and incorporating the effect of geometric nonlinearity is crucial for accurate analysis.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Chien H. Thai, H. Nguyen-Xuan, Lieu B. Nguyen, P. Phung-Van
Summary: A size-dependent moving Kriging meshfree approach is proposed for analyzing bending, free vibration, and buckling of functionally graded microplates. The study uses virtual work principle, mixed rule for material properties, and refined plate theory to determine displacement, natural frequencies, and buckling loads of FG microplates. Results demonstrate that natural frequencies, buckling loads, and displacements of FG microplates are influenced by geometrical parameters, boundary conditions, and length-scale parameters.
ENGINEERING WITH COMPUTERS
(2022)
Article
Engineering, Multidisciplinary
Behrouz Karami, Mergen H. Ghayesh
Summary: This work presents a study on the vibrations of sandwich microshells with porous functionally graded face sheets, considering the in-surface curvilinear motions. The motion equations are derived using the Hamilton principle with a curvilinear framework for the modified couple stress (MCS) scheme. The vibration modes and natural frequencies are obtained numerically, and the effects of different layer arrangements, material compositions, and porosity-type imperfections are investigated. The results are verified through comparison with an ANSYS model and other simplified versions.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2023)
Article
Construction & Building Technology
Lahcene Fortas, Abderraouf Messai, Tarek Merzouki, Mohammed Sid Ahmed Houari
Summary: This paper investigates the buckling behavior of functionally graded graphene reinforced porous nanocomposite beams using the finite element method and trigonometric shear deformation theory. The effects of porosity distribution and GPL dispersion pattern on the nanocomposite beam's response are studied, providing insights into achieving improved buckling behavior.
STEEL AND COMPOSITE STRUCTURES
(2022)
Article
Mechanics
G. G. Sheng, Yan Han, Zihang Zhang, Lei Zhao
Summary: This study investigates the nonlinear free and forced vibrations of functionally graded cylindrical microshells conveying viscous fluid, considering size effects and viscous forces. The critical flow velocity and natural frequency are obtained numerically, and the effects of axial load, scale parameter, fluid flow velocity and viscosity on nonlinear dynamic response are studied. Comparisons with inviscid case and previous literature are also discussed.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Aerospace
Armagan Karamanli, Metin Aydogdu, Thuc P. Vo
Summary: This paper presents a comprehensive study on bending, vibration and buckling behaviours of multi-directional FG microplates using a finite element model. The effects of material length scale parameters, aspect ratio, gradient indexes, and boundary conditions on the displacements, natural frequencies and buckling loads are investigated. New results not available in open literature are provided for future studies.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Mechanics
M. Pakseresht, R. Ansari, M. K. Hassanzadeh-Aghdam
Summary: This paper discusses a coating solution for protecting titanium-based composites and utilizes the Mori-Tanaka method to determine the properties of the composite. The experimental results show that an increase in the thickness of the carbon coating has a negative effect on the elastic properties and stress-strain curve of the composite.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Mechanics
Mahdi Salehi, Raheb Gholami, Reza Ansari
Summary: This study presents an analytical solution approach to examine the nonlinear vibration of geometrically imperfect functionally graded porous circular cylindrical shells reinforced with graphene platelets (GPL) surrounded on an elastic foundation. The effective mechanical properties of considered functionally graded graphene platelet-reinforced porous nanocomposites are characterized via a micromechanical model. The nonlinear frequency response curves are obtained with the use of the method of multiple scales.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Acoustics
Hamed Hatami, Ahmad Bagheri, Reza Ansari
Summary: This article comprehensively analyzes the free vibration of beam-type liquid micro-pump using a free boundary approach and employs the Newmark method to obtain the natural frequencies, mode shapes, and fluid oscillations of the coupled system. The comparison between free and fixed boundary methods reveals a slight deviation in natural frequency for small oscillations of the Euler-Bernoulli micro-beam, which can be negligible.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Materials Science, Multidisciplinary
M. Eghbalian, R. Ansari, S. Haghighi
Summary: A two-stage MD-FE modeling method is developed to investigate the influence of functionalized carbon nanotubes on the mechanical properties of polymer materials. MD simulations and FE modeling are used to study the effects of nanotube properties and polymer matrix composition on the strength and stiffness of the materials. In addition, the volume fraction of nanofillers and the percentage of functionalization have significant effects on the material performance.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Chemistry, Physical
M. Eghbalian, R. Ansari, S. Haghighi
Summary: The tensile properties and fracture mechanism of hydroxyl-functionalized silicon carbide nanotubes (O-fSiCNTs) inserted into polymer matrices were studied using molecular dynamics (MD) simulations based on the notion of representative volume elements (RVEs). The incorporation of chemisorbed nanotubes in polymers significantly enhances their mechanical properties. The O-fSiCNTs/PE and O-fSiCNTs/PP demonstrate lower Young's modulus, maximum stress, and strain energy compared to the O-fCNTs/PE and O-fCNTs/PP. The zigzag O-fSiCNTs/polymer exhibit lower bearable maximum strains in response to loads as opposed to the O-fCNTs/polymer.
MOLECULAR SIMULATION
(2023)
Article
Physics, Multidisciplinary
M. Bazdid-Vahdati, R. Ansari, A. Darvizeh
Summary: This paper presents two hyperelastic models for micromorphic hyperelasticity, which are suitable for materials with high dependence on the microdeformation gradient. Two new strain measures based on the microdeformation gradient are introduced and used in the hyperelastic formulation. The developed formulation allows for clear discussion of the dependency on the microdeformation gradient and the formulation of various types of hyperelastic models using the defined strain measures.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Mechanics
Alireza Beheshti, Reza Ansari
Summary: The current work focuses on analyzing the large deformation of shells made of a transversely isotropic material. A higher-order shell model is used to derive strains and extract the stress field of a hyperelastic medium. The weak form is obtained by utilizing the principle of virtual work. A four-node shell element is developed to address locking issues and incorporate transverse shear, membrane, and curvature-thickness locking for a compressible anisotropic medium. Several examples are presented to demonstrate the performance of the proposed element and the effects of anisotropy.
Article
Physics, Multidisciplinary
Y. Gholami, R. Ansari, R. Gholami
Summary: This paper examines the free vibration of single-layered graphene sheets (SLGSs) subjected to compressive in-plane loads and embedded in a Winkler-Pasternak elastic medium. It uses the high-order Cauchy-Born (HCB) method, hyperelastic membrane and second gradient elasticity theory to provide a mathematical formulation. The variational differential quadrature (VDQ) method and Hamilton's principles are applied to obtain a set of discretized governing equations of motion.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Engineering, Mechanical
Babak Ramazani Darvazi, Javad Rezapour, Saeed Rouhi, Raheb Gholami
Summary: In this paper, the nonlinear vortex-induced vibration of electrostatically actuated microbeam is studied based on modified strain gradient theory. The effects of mid-plane stretching, electrostatic actuation, Casimir and intermolecular forces are considered. By applying the Hamilton's principle and using the Galerkin method, the governing equations of motion are derived and the dynamic response and various characteristics are analyzed.
JOURNAL OF VIBRATION ENGINEERING & TECHNOLOGIES
(2023)
Article
Mechanics
R. Ansari, M. Zargar Ershadi, M. Faraji Oskouie, H. Rouhi
Summary: This paper proposes a novel numerical approach to study the large-amplitude geometrically nonlinear vibrations of circular plates made of functionally graded porous materials subjected to hygrothermal loading on an elastic foundation. The modified Voigt's rule of mixture is used to estimate the hygrothermo-mechanical properties of the plates. The effects of hygroscopic stresses and different distribution patterns for porosity are considered. The governing equations for the vibrations are derived based on the first-order shear deformation plate theory and von-Karman geometrical nonlinear relations, and the Winkler-Pasternak model is used to incorporate the effect of the elastic foundation. The problem is solved using the generalized differential quadrature, variational differential quadrature, and Newmark-beta integration methods, and the influences of various parameters on the geometrically nonlinear vibrations are analyzed.
Article
Computer Science, Interdisciplinary Applications
Peyman Aghdasi, Shayesteh Yousefi, Reza Ansari
Summary: This paper uses DFT and FEM to study the elastic, vibrational and buckling properties of monolayer bismuthene. The developed model accurately predicts Young's modulus of the monolayer bismuthene. The influence of the vertical side length on the fundamental natural frequency is negligible, while vibrational characteristics are significantly affected by the horizontal side length.
ENGINEERING COMPUTATIONS
(2023)
Article
Engineering, Civil
R. Ansari, M. Zargar Ershadi, H. Akbardoost Laskoukalayeh, H. Rouhi
Summary: This article develops a numerical approach to study the geometrically nonlinear vibrations of annular sector plates made of functionally graded materials (FGMs) due to cooling shock. The effects of various parameters on the large-amplitude vibrations of annular sector plates are investigated through numerical simulations.
THIN-WALLED STRUCTURES
(2023)
Article
Mechanics
Hamidreza Yademellat, Reza Ansari, Abolfazl Darvizeh, Jalal Torabi, Ali Zabihi
Summary: This study investigates the size-dependent dynamic pull-in instability of piezoelectrically and electrostatically actuated micro/nanobeams using the nonlocal strain gradient theory. The effects of flexoelectricity and piezoelectricity are considered, and various nonlinear forces are taken into account. The analysis method used in this study improves the reliability of the research model by comparing the results with existing literature.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Mechanics
M. Rasoolpoor, R. Ansari, M. K. Hassanzadeh-Aghdam
Summary: This study investigates the low velocity impact behavior of multi-walled carbon nanotube (MWCNT)-aluminum (Al) nanocomposite plates. The material properties of the nanocomposites are obtained using the rule of mixture, considering microstructural features of MWCNTs such as quantity, aspect ratio, alignment, waviness, and agglomeration. The finite element method is utilized to analyze the dynamic behavior of the plates. The results show that the addition of MWCNTs increases contact force and decreases plate center deflection and impact duration. Higher volume fraction, aspect ratio, straight shape, and uniform dispersion of MWCNTs lead to lesser center deflection in the nanocomposite plates.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
