Article
Engineering, Multidisciplinary
Guangyang Fu, Zhenjie Zhang, Jie Fu, Hongyu Zheng
Summary: This study investigates the size-dependent buckling response of micro-components and the relationship among couple stress theories, modified couple stress theory, and general strain gradient theory. The results show that the general theory can predict the size dependency more accurately and capture more details of the buckling response compared to the reduced theories.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Engineering, Civil
Guangyang Fu, Shenjie Zhou
Summary: A size-dependent model is developed for a laminated microbeam with a partially covered flexoelectric layer, using isotropic flexoelectric theory. The study reveals that the charge, potential, polarization, and deflection are dependent on the ratio of beam thickness and material length-scale parameters. Additionally, an optimum length and thickness of the flexoelectric layer exist to achieve maximum induced charge and deflection.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Electrical & Electronic
Oscar Zi Shao Ong, Mergen H. Ghayesh, Shahid Hussain
Summary: This article investigates the vibration behavior of a double-microbeam system using an assumed-mode expansion technique and finite-element verifications. The study reveals that increasing the couple-stress-tensor-related parameter or stiffness coefficient of the elastic connection can enhance the natural frequencies of the system, and the free vibration characteristics vary under different boundary conditions.
MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS
(2021)
Article
Materials Science, Multidisciplinary
Junling Si, Shujuan Yi
Summary: This study develops a quasi-3D model based on a new modified couple stress theory as a benchmark for analyzing thermal size effects of composite laminated micro plate. Two simplified quasi-3D models are also proposed. Several conclusions can be drawn from numerical results obtained from a classical example of simply-supported micro laminated square plate.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Mechanics
Abbas Rahi
Summary: The modified couple stress theory (MCST) is applied to investigate the size effect on dynamic response of multiple-layer microbeams in this study. Governing equations are derived using MCST and Hamilton's principle, followed by analytical calculation of natural frequencies. The results highlight the significant influence of material length-scale parameters and dimensions of each layer on the vibration characteristics of multiple-layer microbeams.
ARCHIVE OF APPLIED MECHANICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Hongwei Liu, ShiXin Shen, Khaled Oslub, Mostafa Habibi, Hamed Safarpour
Summary: This research investigates amplitude motion and frequency simulation of a thick annular microsystem with graphene nanoplatelets reinforcement using the modified couple stress theory (MCST). The Halpin-Tsai micromechanics model is employed to model the effective Young module, and the generalized differential quadrature method (GDQM) is used to obtain eigenvalues and eigenvectors of the microsystem. Results show that under certain conditions, the influence of length scale parameter on the amplitude and frequency of the microsystem can be ignored, and increasing the thickness of the graphene nanoplatelets decreases this influence on frequency.
ENGINEERING WITH COMPUTERS
(2022)
Article
Materials Science, Multidisciplinary
Shueei-Muh Lin, Ching-Yao Chang
Summary: This paper presents a mathematical model of an AFM nonuniform probe in the modified couple stress theory and proposes an analytical method for designing the configuration of the AFM probe satisfying the integer-multiples relation among frequencies. By tuning the varying cross-section of the probe, specific requirements can be met, and the relations among the natural frequencies, the effective spring constant, and the geometry parameters are discovered. Specific frequencies and spring constant can be obtained by adjusting the probe parameters via these relations.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2022)
Article
Mechanics
R. Resmi, V. Suresh Babu, M. R. Baiju
Summary: This study analyzes the impact of energy dissipation and critical dimensions on the quality factor of micro- and nanoscale resonators. By optimizing dimensions and selecting appropriate materials, the quality factor can be maximized. The results of this study provide guidance for designing high-performance, low-loss resonators at the micro/nanoscale.
Article
Mechanics
Aria Ghabussi, Negin Ashrafi, Aghil Shavalipour, Abolfazl Hosseinpour, Mostafa Habibi, Hossein Moayedi, Behzad Babaei, Hamed Safarpour
Summary: The study investigates the vibrational characteristics of a cylindrical nanoshell reinforced by graphene nanoplatelets, coupled with a piezoelectric actuator, and embedded in a viscoelastic medium. The material properties of the graphene-reinforced composite are assumed to be graded in the thickness direction and analyzed using a nanomechanical model. Various factors, such as the viscoelastic foundation, piezoelectric layer, and graphene distribution pattern, are found to play important roles in the frequency characteristics of the nanoshell, providing useful insights for the design of materials science and nano-electromechanical systems.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2021)
Article
Mechanics
Pham Hong Cong, Do Van Thom, Doan Hong Duc
Summary: This paper investigates the crack propagation behavior of plane strain micro-plates using the modified couple stress theory and the phase-field theory. A phase-field formulation for fracture mechanics based on the framework of the modified couple stress is established for the first time. The results highlight the difference in mechanical properties during crack propagation when considering size-effect based on modified couple stress. This work is important for scientists studying the fracture development process in microstructures.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Mechanics
Cancan Liu, Jiangong Yu, Bo Zhang, Xiaoming Zhang, L. Elmaimouni
Summary: This study investigates the propagation characteristics of Lamb-type waves in a functionally graded piezoelectric small-scale plate using an extended Legendre orthogonal polynomial method. The results show that size and piezoelectric effect increase the phase velocity of Lamb waves, while piezoelectricity suppresses the influence of couple stress on dispersion characteristics.
COMPOSITE STRUCTURES
(2021)
Article
Physics, Multidisciplinary
Hamid M. Sedighi, Ahmed E. Abouelregal, S. Ali Faghidian
Summary: This study investigates the deficiency of the modified couple stress theory in accurately describing the material response of continua with nano-structural features. By reassessing the flexure mechanics of nano-scale beams within this theory, physically motivated constitutive laws are introduced and the effects of symmetric rotation gradients and transverse shear deformation are examined. Additionally, closed-form analytical formulae for the elastic modulus of Carbon Nanotubes are derived and the applicability of the modified couple stress beam model in accurately capturing size-effects in nano-materials is rigorously examined.
Article
Engineering, Multidisciplinary
Yu-fang Zheng, Li-Chuan Liu, De-yong Qu, Chang-ping Chen
Summary: This article presents the nonlinear postbuckling behavior of magneto-electro-thermo-elastic (METE) laminated microbeams. Based on the modified couple stress theory and Reddy's three-order shear deformation theory, along with the von Karman geometric nonlinearity, the nonlinear static model of METE laminated microbeam is established. The nonlinear governing equations and boundary conditions are derived using the principle of virtual work principle. An analytical method is then used to describe the nonlinear postbuckling behavior of METE laminated microbeam with simple supported and clamped boundary conditions. Numerical examples are provided to reveal the effects of various parameters on the critical buckling load and postbuckling response, as well as the distribution of magneto-electric potential through the thickness direction of the microbeam with different lay-up modes.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Physics, Multidisciplinary
Masoud Rezaei, Ahmad Reza Khorshidvand, S. Mahdi Khorsandijou, Mohsen Jabbari
Summary: Using modified couple stress and Mindlin plate theory, this study conducts a parametric study on the effect of length scale parameter on postbuckling of saturated poroelastic rectangular microplates with functionally graded pore distribution. The nonlinear eigenvalue problem with coupled partial differential equations of equilibrium is solved by discretizing the governing equations and using Newton-Raphson iterations. The results reveal how geometric parameters, pore distribution, the Skempton's coefficient, porosity, and different supports modify the influence of length scale parameter on the microplate postbuckling.
Article
Mathematics
Iqbal Kaur, Kulvinder Singh, Eduard-Marius Craciun
Summary: This paper focuses on the two-dimensional deformation in fibre-reinforced composites under concentrated inclined load, employing the new modified couple stress thermoelastic theory (nMCST). The mathematical model is constructed using Lord Shulman heat conduction equation with hyperbolic two temperature (H2T) form. Fourier and Laplace transform are applied to obtain the expressions of physical quantities, including displacement components, thermodynamic temperature, conductive temperature, axial stress, tangential stress, and couple stress. The effects of hyperbolic and classical two temperature on these physical quantities are realistically illustrated.
Article
Engineering, Multidisciplinary
M. Rahaeifard, M. T. Ahmadian, K. Firoozbakhsh
APPLIED MATHEMATICAL MODELLING
(2015)
Article
Engineering, Multidisciplinary
M. Rahaeifard
COMPOSITES PART B-ENGINEERING
(2015)
Article
Engineering, Multidisciplinary
M. Rahaeifard, M. T. Ahmadian
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2015)
Article
Mechanics
M. Mojahedi, M. Rahaeifard
INTERNATIONAL JOURNAL OF APPLIED MECHANICS
(2015)
Article
Engineering, Multidisciplinary
M. Rahaeifard
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2016)
Article
Engineering, Multidisciplinary
M. Mojahedi, M. Rahaeifard
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2016)
Article
Engineering, Biomedical
E. Yassini, M. Mirzaei, A. Alimi, M. Rahaeifard
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2016)
Article
Engineering, Multidisciplinary
M. Rahaeifard, M. Mojahedi
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2017)
Article
Engineering, Civil
M. Rahaeifard, M. Mojahedi
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2017)
Article
Engineering, Civil
A. Karimzadeh, M. T. Ahmadian, K. Firoozbakhsh, M. Rahaeifard
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2017)
Article
Thermodynamics
S. Zandekarimi, B. Asadi, M. Rahaeifard
JOURNAL OF THERMAL STRESSES
(2018)
Article
Engineering, Multidisciplinary
M. Rahaeifard, M. T. Ahmadian, K. Firoozbakhsh
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2014)
Article
Engineering, Mechanical
Masoud Rahaeifard, Mohammad Taghi Ahmadian, Keikhosrow Firoozbakhsh
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2014)
Article
Engineering, Multidisciplinary
A. Karimzadeh, M. T. Ahmadian, M. Rahaeifard
Article
Engineering, Multidisciplinary
Tohya Kanahama, Motohiro Sato
Summary: This study theoretically explains the effect of initial deflection and initial slope on self-buckling characteristics of heavy columns and proposes a formula characterizing the self-buckling problem. The results show that the greatest height is proportional to the 2/3 power of radius, and the formula can potentially predict the height of tree-like natural structures.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2024)
Article
Engineering, Multidisciplinary
Aps Selvadurai, Alexander P. Suvorov
Summary: This paper examines the torsion of a solid cylinder made of a fluid-saturated porous medium with a hyperelastic porous skeleton. It analyzes the mechanics of the twisted cylinder in both short-term and long-term behaviors, using numerical solutions and the ABAQUSTM finite element code.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2024)
Article
Engineering, Multidisciplinary
S. Kanaun
Summary: This study focuses on spherical radially transverse isotropic heterogeneous inclusions in homogeneous isotropic conductive host media. The volume integral equation for the field in the medium with an isolated inclusion subjected to a constant external field is solved using Mellin-transform technique. The method allows revealing tensor structure of the solution with precision to one scalar function of radial coordinate. The study also investigates the influence of neutral inclusions and conductivity coefficients on the effective conductivity of the composite material.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2024)
Article
Engineering, Multidisciplinary
Marinos Kattis, Vassilis Tsitsos, Vassilis Karatzaferis
Summary: The proposed model utilizes continuum mechanics to describe the mechanical behavior of a weakened interface between materials with microstructure, simulating the weakened interface using a surface elastic medium adhering on either side with bulk elastic continua. The model is able to investigate the effect of a weakened interface on stress concentration around inhomogeneities embedded in an unbounded matrix of Cosserat materials.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2024)
Article
Engineering, Multidisciplinary
Shixiang Zhao, Yu. V. Petrov, Yuyi Zhang, G. A. Volkov, Zejian Xu, Fenglei Huang
Summary: This paper theoretically studies the thermal softening related to stress relaxation using the incubation time approach and examines the temperature-time correspondence. The developed relaxation model of plasticity (RP model) is analyzed and compared with other constitutive models and artificial neural networks. The advantages and disadvantages of different models are discussed, and the differences between the ANN model and other constitutive models are examined.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2024)
Article
Engineering, Multidisciplinary
Ivan I. Argatov, Federico J. Sabina
Summary: This study models a seismic metabarrier as a cluster of single-degree-of-freedom resonator units and considers the scattering effects on pulsed Rayleigh waves caused by the vertical displacements of the resonators and the normal contact forces. The variation of the amplitude reduction factor due to the model parameters variation is studied in detail.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2024)