Article
Physics, Condensed Matter
Jingjing Feng, Huajian Yu, Sai Ma, Shuying Hao, Ruiqin Wu
Summary: This paper examines the axial vibration behavior of mass sensors based on single-walled carbon nanotubes and establishes frequency equations and response relationships to describe their vibration characteristics. By combining theoretical analysis and molecular dynamics simulations, the influence of various physical factors on vibration behavior is studied, and methods to improve sensitivity are proposed.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Mechanics
Jingjing Feng, Huajian Yu, Yanjie Li, Wei Zhang
Summary: This study investigates the nonlinear oscillation behavior and detection sensitivity of mass sensors based on carbon nanotubes. By introducing geometric nonlinearities and size effects, a dynamic model is established, and nonlinear response equations and frequency shift equations are obtained. Molecular dynamics simulations are used to verify the nonlinear oscillation behavior of the sensors.
COMPOSITE STRUCTURES
(2023)
Article
Automation & Control Systems
Xianfa Cai, Lizhong Xu
Summary: This study established a multifield coupled dynamics model to investigate the impact of nonlocal effects on the performance of CNT resonant mass sensors, showing that the coupling between nonlocal elastic parameter and electromagnetic force significantly affects the natural frequency of the CNT.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Mathematics, Applied
Ahmad Mamandi
Summary: In this paper, the frequency stability analysis for a viscoelastic carbon nanotube under the Kelvin-Voigt material model with slip boundary condition on a viscoelastic foundation and axial load is conducted using nonlocal Euler-Bernoulli thin beam theory. The governing equations of motion and their associated boundary conditions are derived using the Hamilton principle. The stability analysis is performed using mode summation technique and extended Galerkin method, and the effects of various parameters on the occurrence of instability modes are investigated.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Chemistry, Multidisciplinary
Lu Qiu, Feng Ding
Summary: Revealing the true picture of the carbon nanotube growth front at the catalyst surface is crucial for understanding the mechanism of controlled CNT growth. Through simulation experiments, it has been found that a clean CNT-catalyst interface dominates the growth kinetics during real CNT experimental growth, indicating the feasibility of controlling CNT growth by tuning the CNT-catalyst interface.
Article
Chemistry, Multidisciplinary
Fan Wu, Yushun Zhao, Yifan Zhao, Yue Zhao, Chao Sui, Xiaodong He, Chao Wang, Huifeng Tan
Summary: Fiber-based fabrics have great potential in impact protection, and a novel nanostructure using SWCNTs to weave 2D films has been proposed. Through MD simulation, it was found that SWFs exhibit significant anisotropy in mechanical properties, with the best performance when loaded along the CNT axis. The SWF demonstrated high strength and energy absorption, attributed to the intrinsic strength and flexibility of CNTs.
Article
Mechanics
Hossein Pakdaman, Mojtaba Roshan, Soroush Soltani
Summary: This paper investigates the free vibrational behavior of two crossed graphene nanoribbons (GNRs) in an elastic medium using nonlocal continuum-based models and van der Waals (vdW) forces. Numerical studies show that considering non-uniform vdW forces and the intersection angle significantly affect the vibration of the system.
Article
Mathematics, Applied
Maysam Naghinejad, Hamid Reza Ovesy
Summary: The viscoelastic buckling and nonlinear post-buckling behavior of nano-scaled beams were analyzed using the nonlocal integral elasticity theory. The study developed a finite element method and considered buckling related terms and viscoelastic effects. The results were compared with literature and the effects of nonlocal parameter, viscoelastic parameter, axial compressive load, and boundary conditions on the buckling and post-buckling behavior were investigated.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2022)
Article
Physics, Fluids & Plasmas
K. A. Nichols, S. X. Hu, A. J. White, V. N. Goncharov, D. I. Mihaylov, L. A. Collins, N. R. Shaffer, V. V. Karasiev
Summary: This article focuses on the importance of nonlocal electron transport and proposes improvements to current models in order to accurately predict electron conduction in inertial confinement fusion simulations. The authors utilized time-dependent density functional theory to calculate the electron stopping power in polystyrene plasmas and developed a global analytical model for electron stopping range. The model was implemented in simulations of laser-direct-drive ICF implosions.
Article
Chemistry, Physical
Ziwei Xu, Feng Ding
Summary: This study demonstrates that zigzag or near-zigzag SWCNTs are highly sensitive to the size of the docked catalyst particle, while armchair or near-armchair SWCNTs are less sensitive. A small change in catalyst particle size can lead to a variation in SWCNT chirality for zigzag tubes, but not for armchair tubes. This research provides quantitative guidance for SWCNT cloning and deepens understanding of SWCNT growth mechanisms.
Article
Materials Science, Multidisciplinary
Leysan Kh Galiakhmetova, Elena A. Korznikova, Aleksey A. Kudreyko, Sergey Dmitriev
Summary: Aligned carbon nanotube bundles exhibit negative lateral thermal expansion under lateral loading and heating conditions. The coefficient of thermal expansion is practically constant up to 1500 K and does not depend on biaxial lateral compression. This anomalous behavior is explained by the elliptization of the CNT cross section and bending of the CNT walls by thermal fluctuations.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Chemistry, Physical
Jianian Hu, Zhengyuan Liu, Yongyuan You, Haotian Zhang, Xiang Chen, Yi Sun, Jian Zhang, Guoqiang Luo
Summary: This study used ex-situ transmission electron microscopy observations and molecular dynamics simulation methods to investigate the process of forming carbon nanotube forests catalyzed by Fe nanoparticles. The results reveal the rooting path of C in Fe and its motion evolution mechanism. It is found that C reacts with Fe to form Fe3C, and C enters from Fe (110) crystal plane, which transforms Fe (110) crystal plane into Fe3C (013) crystal plane. C then precipitates and grows into carbon nanotubes from Fe3C, creating the parallel relationship between the growth direction of carbon nanotubes and Fe3C (013) crystal plane. Molecular dynamics simulation also confirms the correctness of the experimental results by showing consistent motion paths of C.
COLLOID AND INTERFACE SCIENCE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Farshid Darvishi, Omid Rahmani
Summary: This paper investigates the free vibration behavior of coiled carbon nanotubes (CCNTs) using continuum mechanics methods and molecular dynamics simulations. A new elasticity model, called the nonlocal generalized Washizu beam (NGWB), is proposed to consider the effects of curvature, cross-section thickness, and size-dependent effect on nanotubes. The governing equations are derived and solved using the numerical generalized differential quadrature method (GDQM). MD simulations are performed to validate and evaluate the obtained results. The study finds that the nonlocal parameter has a significant effect on the frequencies of CCNTs with smaller geometrical parameters, and the type of boundary conditions affects the calibrated values of the nonlocal parameter and arrangement of vibrating mode shapes of CCNTs.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Mechanics
Ehsan Taati, Vahid Borjalilou, Famida Fallah, Mohamad Taghi Ahmadian
Summary: This study investigates the simultaneous effects of shear and small scale on the nonlinear vibration behavior of functionally graded carbon nanotube-reinforced composite beams. A closed-form solution of the nonlinear natural frequency is developed using a hybrid method of Galerkin and perturbation technique. Numerical results show that the distribution of CNTs, boundary conditions, and nonlocal parameter have significant effects on the frequency ratio.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2022)
Article
Mechanics
Farshad Khosravi, Seyyed Amirhosein Hosseini
Summary: This article investigates the forced and free dynamic torsional vibrations of single-walled carbon nanotubes embedded in a viscoelastic medium under a harmonic external torque. It introduces Eringen's nonlocal elasticity to consider the small size effect of nanostructures. The governing equation is simplified to an ordinary differential equation using the Galerkin method in the time domain. The study explores the effects of various parameters on the angular displacement, including the nonlocal parameter, damping ratio, damping coefficient, stiffness of the viscoelastic medium, excitation frequency, geometry, and mass moment of inertia. The results are validated using a finite difference method and compared with a previous study.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2022)
Article
Engineering, Multidisciplinary
B. B. Yin, W. K. Sun, Yang Zhang, K. M. Liew
Summary: This study proposes a novel meshfree framework based on bond-based peridynamics (PD) using finite deformation theory to model the large deformation and progressive fracture of hyperelastic materials. The framework introduces an original bond strain and a numerical damping parameter to improve the solution accuracy and stability of explicit time integration. It outperforms grid-based methods in capturing complex crack features and has been successfully validated in various examples. The framework has wide compatibility with hyperelastic models and has potential applications in elastomer-hydrogel composites and soft tissues modeling.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Mechanical
Jinlong Liu, Bin Bao, Jiatong Chen, Yufei Wu, Quan Wang
Summary: This paper proposes a passively adaptive piezoelectric wind energy harvester with a double-airfoil bluff body to enhance performance subjected to time-varying wind velocity. The associated aero-electromechanical model is developed to investigate the influence of attack angle on energy harvesting performance. Numerical results show three working modes that appear under different attack angles: vortex-induced vibration, galloping, and vibration suppression. Experimental validation shows that the proposed harvester outperforms conventional harvesters.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Ecology
Yalong Wang, Chaoying Li, Haidong Liu, Jin Lin, Shouxiang Lu, Kim Meow Liew
Summary: The electric fault arc, especially the series arc, causes numerous electrical fires. Previous studies have limitations in focusing on gaseous atmospheres instead of solid materials, which is not in line with the actual demand, and in restricting the studied external heat sources to cone heaters and flames, neglecting the electric arc. To overcome these limitations, an experimental platform was developed to investigate flame behavior during the ignition of cable insulation material by the fault arc. A flame-extracting and noise-reduction algorithm was proposed to process the high-speed camera's large number of photos. The main findings include the significant role of the appropriate size of the structuring element in filtering the flame region, the increase in mean flame area with system load growth, and the more prominent flame size and frequency in specific locations with increased system load. The in-depth understanding of flame behavior provided by this work will contribute to optimizing electric system design and disaster prevention.
Article
Mechanics
B. B. Yin, Arslan Akbar, Yang Zhang, K. M. Liew
Summary: This study presents a coupled phase-field cohesive modeling framework that can accurately capture the progressive failure and damage behaviors of multiphasic microstructures and multifiber systems. The framework includes novel aspects such as a newly developed scalar indicator, periodic boundary conditions, and characterization of various failure modes. Parametric studies show consistent results with experiments and reveal the effects of fiber distributions, fiber volume fractions, and boundary conditions on the mechanical behaviors of fiber-reinforced composites. The results demonstrate the potential of the framework in evaluating the mechanical performances of composite materials in engineering applications.
COMPOSITE STRUCTURES
(2023)
Article
Mechanics
D. A. Abdoh, Yang Zhang, A. S. Ademiloye, V. K. R. Kodur, K. M. Liew
Summary: In order to predict the heating and cooling behaviors of laminated glass facades exposed to fire, a precise and efficient computer model is developed. An efficient three-dimensional finite difference method (3DFDM) is proposed to reduce the computational requirements associated with simulating heat transfer in layered structures with a down-flowing water film. A unique computational algorithm for particle labeling is developed to capture the moving particles of the water film, which significantly reduces the computational effort.
COMPOSITE STRUCTURES
(2023)
Article
Construction & Building Technology
Gen Li, Arslan Akbar, Lu-Wen Zhang, Federico Rosei, K. M. Liew
Summary: This article focuses on an original molecular pathway to predict the durability and analyze the environmental impact of fluoroalkyl-silane (FS) based additive modified cementitious composites in marine environment. By revealing the calcium leaching behaviors of cement composites through molecular simulation, the study evaluates the porosity and chloride diffusion coefficient to determine their lifespan. The results show that FS surface modification can eliminate decalcification, decrease porosity, and slow down chloride accumulation. The optimal mixing content of 0.762 wt % FS significantly reduces repair frequencies and diminishes CO2 emissions and non-renewable energy consumption by 52.33% and 31.07% respectively. This research provides atomic understanding for improving the durability of cement composites and proposes strategies to predict their service life and environmental impact.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Chemistry, Analytical
Yalong Wang, Ning Kang, Jin Lin, Shouxiang Lu, Kim Meow Liew
Summary: Flame retardant cables are widely used, but the thermal degradation behavior of PVC cable insulation materials with different flame-retardant levels has not been extensively studied. Four flame-retardant and one non-flame-retardant PVC cable insulation materials were analyzed using thermogravimetric analysis. The results show differences in the first peaks of the thermal degradation behavior, but similarities in the second peaks. Evaluating the flame-retardant performance solely based on activation energy is not sufficient. The findings provide a basis for evaluating the thermal degradation behavior of PVC cable insulation materials and can be useful for numerical simulations of electrical fires.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2023)
Article
Materials Science, Multidisciplinary
Wei-Kang Sun, B. B. Yin, Lu-Wen Zhang, K. M. Liew
Summary: To develop better diagnosis and treatment techniques for cardiovascular diseases, such as aneurysms, it is urgent to have a deeper understanding of the biomechanical mechanisms and failure behaviors of blood vessels. This study proposes a novel virtual bar model for surrounding tissues and correlates the residual stress and loads from the surrounding tissues with the perivascular pressures of the blood vessels. Additionally, a meshfree framework is developed to model the deformation and rupture of blood vessels using the Fung-type hyperelasticity and the Casson's non-Newtonian fluid model. The study successfully captures the blood pressure-induced spontaneous ruptures of blood vessels.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Multidisciplinary Sciences
Yi Zhou, Lunan Yang, Zhen Liu, Yang Sun, Junfei Huang, Bingcheng Liu, Quan Wang, Leyu Wang, Yong Miao, Malcolm Xing, Zhiqi Hu
Summary: We developed a switchable hydrogel film adhesive with pattern-tunable wrinkles to control adhesion, addressing the challenges of on-demand adherence and detachment from tissue surfaces. The generated compressive stress from the bilayer system leads to self-similar wrinkling patterns at different wavelengths, regulating interfacial adhesion. We demonstrated the application of our adhesive in a random skin flap model, showing its potential for tissue sealing, neovascularization promotion, and gradual detachment through dynamic wrinkling pattern transition.
Article
Chemistry, Physical
Xiongfei Gao, Lu-Wen Zhang, K. M. Liew
Summary: This study reveals the electric double layer (EDL) structure at the interface between gallium-based liquid metal (GBLM) electrode and aqueous electrolyte for the first time, using density functional theory (DFT) calculation and ab initio molecular dynamics (AIMD) simulation. The EDL structure originates from the specific adsorption of gallates on GBLM, forming an inner Helmholtz layer (IHL) and attracting a diffusion layer with opposite charges. The excess negative charge on GBLM surface interferes with the adsorbed gallates and amplifies the interface potential change across EDL. The proposed EDL structure contributes to a deeper understanding of the electrochemical processes occurring at the electrode-electrolyte interface in GBLM aqueous batteries.
APPLIED SURFACE SCIENCE
(2023)
Article
Mechanics
A. O. Sojobi, K. M. Liew
Summary: High performance column composites are multifunctional composites designed to improve resilience of structures and infrastructures. They have been found attractive in earthquake-prone regions for their superior mechanical performance.
COMPOSITE STRUCTURES
(2023)
Article
Mechanics
Z. X. Lei, Junwei Ma, W. K. Sun, B. B. Yin, K. M. Liew
Summary: Composite structures can experience significant residual strength reduction due to invisible damage caused by impacts, which can result in severe harm without warning. Incorporating fibers, such as carbon and glass fibers, into composite laminates can enhance their impact resistance and compressive strength. This study investigated the dynamic response and residual strength of laminates reinforced with twill woven carbon fiber, glass fiber, and carbon/glass fiber hybrid under low-velocity impact and compression-after-impact testing. The results showed that adding glass fibers altered the impact damage mode and improved the laminates' impact resistance and compressive strength. The study also characterized the damage morphologies and failure mechanisms of the laminates, providing valuable insights for their structural design and performance improvement.
COMPOSITE STRUCTURES
(2023)
Article
Green & Sustainable Science & Technology
Weiwei Zhang, Hao Yu, Binbin Yin, Arslan Akbar, K. M. Liew
Summary: This review explores the recycling of end-of-life wind turbine blades (EoL-WTBs) and their potential applications in civil engineering. Mechanical, thermal, and chemical recycling methods are examined, highlighting the hierarchical valorization of EoL-WTBs recyclates in construction. However, challenges such as technical complexity, cost, market demand, and regulatory frameworks hinder widespread adoption. Standardization, efficient transportation systems, well-structured recycling supply chains, and economic feasibility analysis are recommended to address these issues.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Green & Sustainable Science & Technology
B. B. Yin, Gen Li, Yang Zhang, K. M. Liew
Summary: In this study, a molecular model was developed to describe the optimized properties of LC3 blend, revealing the relationship between its structure and mechanical properties, tensile deformation behaviors, and failure mechanisms. The findings provide insights into the development of sustainable cementitious composites for the construction industry with lower environmental impacts.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Multidisciplinary
W. K. Sun, B. B. Yin, Arslan Akbar, V. K. R. Kodur, K. M. Liew
Summary: This paper proposes a variable timestep-strategy to accelerate the peridynamic modeling of thermomechanical cracking, and demonstrates its advantages in various aspects.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
