Article
Mechanics
Manjur Alam, Sudib K. Mishra
Summary: This study investigates the geometrically nonlinear vibration of NL-SG beams on a nonlinear substrate with shear interactions. It includes higher-order curvature, von Karman nonlinearity, and a nonlinear Pasternak model for the substrate. The research shows that nonlinear bending and substrate stiffness play a dominant role in influencing the vibration behavior, while the NL and SG interactions significantly affect the vibration behavior with the effect of functional gradation of material being minor.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Multidisciplinary
Pham Toan Thang, Phuong Tran, T. Nguyen-Thoi
Summary: This research paper investigates the vibrational responses of functionally graded carbon nanotube-reinforced composite nanoplates considering the effect of nonlocal parameter and strain gradient coefficient. By studying four types of CNT distribution under small length scale effects, the study aims to estimate the fundamental natural frequencies in FG-CNTRC nanoplates. The mathematical modeling and analytical solutions provide insights into how the small length-scale influences the vibrational behavior of nanoplates.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Engineering, Multidisciplinary
Ahmed Amine Daikh, Mohamed Sid Ahmed Houari, Mohamed Ouejdi Belarbi, Salwa A. Mohamed, Mohamed A. Eltaher
Summary: This manuscript presents a comprehensive study on the effects of thickness stretching on the free vibration, static stability, and bending of multilayer functionally graded carbon nanotubes reinforced composite nanoplates. Nonlocal strain gradient continuum model is used to consider the nanoscale and microstructure influences. Parametric analysis is conducted to explore the impact of different parameters on the stresses, deformation, critical buckling loads, and vibration frequencies.
DEFENCE TECHNOLOGY
(2022)
Article
Computer Science, Interdisciplinary Applications
Pham Toan Thang, Dieu T. T. Do, Jaehong Lee, T. Nguyen-Thoi
Summary: This paper presents an in-depth study on the influence of nanoscale parameters on the bending and free vibration responses of functionally graded carbon nanotube-reinforced composite nanoshells. Mathematical formulas and numerical calculations are used to investigate the effect of nanoscale parameters, material properties, and shell shapes on the deflection and fundamental frequency parameters of the nanoshells.
ENGINEERING WITH COMPUTERS
(2023)
Article
Construction & Building Technology
Jia-Qin Xu, Gui-Lin She, Yin-Ping Li, Lei-Lei Gan
Summary: This paper fills the gap in the existing literature by considering the influences of geometric nonlinearity and initial geometric imperfection in the resonance problem of nanoplates. Nonlinear resonances of functionally graded nanoplates with initial geometric imperfection under different boundary conditions are established based on the nonlocal strain gradient theory. The equations of motion are derived using the Euler-Lagrange principle and solved with the perturbation method, and the effects of various factors on the nonlinear forced vibration behavior of nanoplates are discussed.
STEEL AND COMPOSITE STRUCTURES
(2023)
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
Mechanics
Chang Li, Hai Qing
Summary: In this work, a nonlocal strain gradient integral model is used to study the free damping vibration analysis of functionally graded viscoelastic Timoshenko microbeams with immovable boundary conditions in thermal environment. The microbeams are modeled using the Kelvin-Voigt model and the differential governing equations and corresponding boundary conditions are derived using Hamilton's principle. By combining the nonlocal strain gradient integral model and Kelvin-Voigt viscoelastic model, the integral constitutive equations of nonlocal stress with thermal effect are derived and converted into a differential form with constitutive constraints. The size-dependent axial force due to thermal expansion is explicitly derived and the bending deflection, moment, cross-sectional rotation, and shear force are computed using Laplace transformation for linear thermo-elastic vibration. A two-step numerical method is proposed to solve the elastic vibration frequency and damping ratio, and numerical investigations are conducted to explore the influences of various parameters on the vibration frequencies and damping ratio.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Chemistry, Physical
Rabab A. A. Alghanmi
Summary: This paper presents a static analysis of functionally graded nanoplates with porosities by combining nonlocal strain gradient theory and four-variable shear deformation theory. The proposed model captures the effects of both nonlocal and strain gradient on the nanoplate structures by incorporating corresponding factors into the elastic constants of the nanoplate.
Article
Mechanics
Kalyan Boyina, Raghu Piska, Sundararajan Natarajan
Summary: A nonlocal strain gradient model is developed for the buckling analysis of functionally graded Euler-Bernoulli beam subjected to thermo-mechanical loads. The governing equations incorporate the effects of nonlocal and strain gradient parameters. Thermal properties over the cross section are graded using the power law. The proposed model compares well with the existing literature in the limiting sense of no nonlocal and gradient effects.
Article
Mechanics
Yan-Ming Ren, Peter Schiavone, Hai Qing
Summary: In this paper, a nonlocal gradient piezoelectric model capable of distinguishing softening and toughening size-effects due to elasticity and piezoelectricity is proposed. The model is applied to study the static bending of functionally graded piezoelectric nanobeams. The results show that bending deflections increase consistently with the increase of nonlocal parameter and the decrease of gradient parameter for strain-driven model and the decrease of nonlocal parameter and the increase of gradient parameter for stress-driven model.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2022)
Article
Engineering, Mechanical
Nikola Nesic, Milan Cajic, Danilo Karlicic, Aleksandar Obradovic, Julijana Simonovic
Summary: This paper investigates the nonlinear dynamic behavior of a nonlocal functionally graded Euler-Bernoulli beam resting on a fractional visco-Pasternak foundation and subjected to harmonic loads. The proposed model captures both the elastic stress gradient field considering the nonlocal parameter and the strain gradient stress field considering the material length scale parameter. The study demonstrates that the application of the incremental harmonic balance method in analyzing nonlocal strain gradient theory-based structures can lead to more reliable studies for strongly nonlinear systems.
NONLINEAR DYNAMICS
(2022)
Article
Mechanics
Chien H. Thai, A. M. J. Fereira, H. Nguyen-Xuan, P. Phung-Van, P. T. Hung
Summary: In this study, a nonlocal strain gradient isogeometric model for free vibration analysis of magneto-electro-elastic (MEE) nanoplates made of functionally graded (FG) materials is presented. The model takes into account higher-order shear deformation theory, nonlocal strain gradient theory, and isogeometric analysis method. The stiffness of MEE-FG nanoplates is shown to be influenced by two scale parameters. The natural frequency of the nanoplates is evaluated by considering the power-law scheme, geometrical parameter, nonlocal parameter, strain gradient parameter, electric voltage, and magnetic potential. The results obtained using nonlocal strain gradient theory (NSGT) are compared to those obtained using classical theory.
COMPOSITE STRUCTURES
(2023)
Article
Engineering, Civil
Chien H. Thai, P. T. Hung, H. Nguyen-Xuan, P. Phung-Van
Summary: In this paper, a new size-dependent meshfree method is introduced to analyze the free vibrations of magneto-electro-elastic (MEE) functionally graded (FG) nanoplates. The method combines the nonlocal strain gradient theory (NSGT), the higher-order shear deformation theory (HSDT), and meshfree method for the first time. The effective material properties of MEE-FG nanoplates are expressed using a power-law scheme. Numerical examples are given to investigate the effect of various parameters on the natural frequency of MEE-FG nanoplates.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Mechanical
Soroush Sepehri, Mahmoud Mosavi Mashhadi, Mir Masoud Seyyed Fakhrabadi
Summary: In this study, the modified strain gradient theory is used for the first time to model two-dimensional micro-lattices of functionally graded materials. The effect of the functionally graded distribution of materials on the wave propagation and wave filtering performances of these structures is investigated.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Acoustics
Pham Van Vinh, Le Quang Huy
Summary: This study investigates the effects of porosity and nonlocal parameter on the free vibration behavior of nanoplates, showing that both factors have significant impacts on the vibration characteristics of the nanoplates.
SHOCK AND VIBRATION
(2021)
Article
Engineering, Marine
Aman Garg, M. O. Belarbi, H. D. Chalak, L. Li, Anshu Sharma, Mehmet Avcar, Neha Sharma, Sagar Paruthi, Reeta Gulia
Summary: This article investigates the helicoidal laminates inspired by mantis shrimp crustacean, and finds that they can sustain higher loads compared to conventional laminated structures. However, bending studies on these helicoidal structures are still lacking. Buckling and free vibration studies have been carried out on laminated composite and sandwich plates inspired by helicoidal structures, using higher-order zigzag theory.
Article
Engineering, Civil
Haishan Tang, Chenglin Zhang, Li Li, Chaosheng Mei, Ling Ling, Yujin Hu
Summary: This study proposes an analytical framework to address the issue of why some structures have numerous rotations but do not exhibit the auxetic behavior. It quantitatively analyzes the independent effects of direct bending of ligaments and rotation of rigid rings on the mechanical properties of chiral and antichiral honeycombs. The study derives analytical expressions for TTC coefficients, Poisson's ratio, and Young's modulus and reveals the effects of various factors on these properties.
THIN-WALLED STRUCTURES
(2023)
Article
Mechanics
Ahmed Amine Daikh, Mohamed-Ouejdi Belarbi, Abdelhak Khechai, Li Li, Hani M. Ahmed, Mohamed A. Eltaher
Summary: This paper proposes a new nanoplate model to characterize the buckling behavior of bilayer FG porous plates, which can consider both geometric and physical effects. Materials are graded continuously using a power law function. Two types of coated FG plates, Hardcore and Softcore FG plates, are investigated. Based on the generalized field of displacement, a Quasi-3D higher-order shear deformation plate theory is proposed, reducing the number of variables. The proposed solution is validated and is in good agreement with existing literature.
Article
Chemistry, Physical
Ke Duan, Ziyong Li, Juzheng Chen, Li Li, Yujin Hu, Yang Zhang, Jianwei Zhang, Yang Lu
Summary: Through large-scale reactive molecular dynamics simulations, the underlying microstructure evolution mechanisms associated with graphene-guided carbonization in C/C composites were revealed. A gradient evolution effect occurred in the carbon matrix, leading to the formation of additional stacked graphene layers near the introduced graphene sheet. Two microstructure evolution pathways were identified, resulting in significantly improved tensile modulus and strength of the graphene-reinforced C/C composites.
Article
Mechanics
Chenglin Zhang, Sibo Ba, Zifeng Zhao, Li Li, Haishan Tang, Xuelin Wang
Summary: Inspired by natural materials, researchers propose a new category of hierarchical chiral structure to enhance its energy absorption capacity. The hierarchical chiral structure is constructed by replacing the central ring with a group of smaller rings connected by ligaments. Numerical analysis shows that hierarchical anti-tetrachiral structures exhibit a unique necking deformation mode at low impact speeds. Moreover, second-order anti-tetrachiral structures not only improve specific mass and volume energy absorption, but also effectively reduce peak stress compared to first-order structures. These findings contribute to the design of crashworthy auxetic components.
COMPOSITE STRUCTURES
(2023)
Article
Engineering, Mechanical
Yiyuan Jiang, Li Li, Yujin Hu
Summary: When the external stimuli have a similar length scale to most chain lengths within a polymeric solid, nonlocal and microstructure-dependent strain-gradient effects become significant. This study proposes a physically-based nonlocal strain gradient theory for polymer networks, where the kernel functions and intrinsic length scales have clear physical meanings. The main contribution lies in establishing a general framework that can incorporate various microscopic descriptions and derive a corresponding nonlocal strain gradient constitutive relation.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Mechanical
Aman Garg, Mohamed-Ouejdi Belarbi, Li Li, Neha Sharma, Ayushi Gupta, Hanuman Devidas Chalak
Summary: This article aims to conduct a free vibration analysis of biological-inspired laminated composite (B-ILC) plates with helicoidal layup using the higher-order zigzag theory (HOZT). The effects of boundary conditions, geometric properties, number of layers, skew angle of the plate, and material properties on the free vibration behavior are studied in detail.
JOURNAL OF STRAIN ANALYSIS FOR ENGINEERING DESIGN
(2023)
Article
Engineering, Mechanical
Sheng Lei, Wei Tian, Li Li
Summary: An adjoint variable method is proposed in this paper for sensitivity analysis of performance metrics. By defining a function to render these performance metrics in scalar form and analyzing them in a unified form, the sensitivity of performance metrics can be directly calculated. Through comparison with the direct differentiation method and numerical validation, the results show that this method is more effective for performance metrics with multiple design variables.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Chenhao Xu, Li Li
Summary: A bio-inspired nanocomposite is designed and fabricated with common microstructural features inspired by bones to overcome the trade-off between stiffness and damping. The role of these features on damping is investigated through experimental and theoretical research. The inclusion of intramolecular dangling chains improves damping, while the high modulus of multi-walled carbon nanotubes (MWCNTs) enhances the overall stiffness and induces an inelastic strain process at the interface to dissipate mechanical energy. The synergistic enhancement mechanism between the dangling chains and the moduli-mismatching interface leads to remarkably stiff yet lossy performances.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Mechanics
Fei Wang, Li Li, Xinli Jiang, Haishan Tang, Xuelin Wang, Yujin Hu
Summary: This study presents a novel aluminum matrix composite reinforced by a diamond lattice-inspired carbon nanotube skeleton. By molecular dynamics simulation, it is shown that the structure can increase internal friction and ensure sufficient modulus through cooperative deformation, achieving a trade-off between damping and modulus.
COMPOSITE STRUCTURES
(2023)
Article
Engineering, Civil
Ahmed Amine Daikh, Mohamed-Ouejdi Belarbi, Abdelhak Khechai, Li Li, Samir Khatir, Alaa A. Abdelrahman, Mohamed A. Eltaher
Summary: The main objective of this research is to analytically analyze the static problem of a new model of functionally graded materials, known as the bi-coated FGM plate, and propose a Quasi-3D higher-order shear deformation plate theory. The model is validated and numerical results demonstrate the impact of hardcore and softcore distributions, gradation indices, and boundary conditions on static bending deflection and stresses of the bi-coated FGM plate.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Multidisciplinary
Yiyuan Jiang, Li Li, Yujin Hu
Summary: A physically-based strain gradient viscoelasticity theory is proposed for polymer networks, considering both the strain gradient effect and the history-dependent behavior. The microstructure-dependence and history-dependence of stress and hyperstress are interpreted physically and quantitatively. The chain representation of the Helmholtz free energy density is transformed to the strain gradient continuum field representation through the geometric connection.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2023)
Article
Engineering, Mechanical
Chaosheng Mei, Li Li, Xiaobai Li, Yiyuan Jiang, Xiangzhen Han, Haishan Tang, Xuelin Wang, Yujin Hu
Summary: The concept of spatiotemporal damping is proposed to quantify the inherent wave attenuation property of dissipative metamaterials. The concept of spatiotemporal damping is more general compared to its counterparts in previous studies such as band gap and damping. Spatiotemporal damping results from the coupling effect of energy dissipation and energy scattering, and the coupling mechanism is revealed in this study.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Yu Fu, Li Li, Yujin Hu
Summary: Computational cost and robustness pose significant challenges in topology optimization methods for optimizing large-scale multiphysical structures. This study proposes an efficient and robust topology optimization method for reducing thermoelastic damping in large-scale microresonators. The method incorporates an evolutionary structural optimization method and a model reduction method based on the projection-based model reduction method.
APPLIED SCIENCES-BASEL
(2023)
Article
Materials Science, Multidisciplinary
Rongjiang Tang, Taoqi Lu, Weiguang Zheng, Li Li
Summary: This study aims to reveal the significant contribution due to the interplay between intrinsic and extrinsic lengths, which is of fundamental scientific interest. The nonlocal theory is employed to examine the dynamical behaviors of the ABH incorporating the effect of intrinsic lengths. It is found that the effect of the microstructure-dependent nonlocality becomes significant and the ABH shows a better absorption of acoustic energy when the nonlocal intrinsic length tends to be larger.
RESULTS IN PHYSICS
(2023)
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)
