Article
Materials Science, Multidisciplinary
Yeran Shi, Wenting Ye, Dongpeng Hua, Qing Zhou, Zhuobin Huang, Yuxin Liu, Shuo Li, Ting Guo, Yongnan Chen, Stefan J. Eder, Haifeng Wang
Summary: This article reports a groundbreaking study on CoCrFeMnNi/Gr nanocomposites, highlighting their exceptional mechanical properties. The authors use molecular dynamics simulations to reveal the profound impact of graphene on the nucleation and propagation of dislocations in HEAs. They demonstrate that the high stresses at the interface between HEA and graphene lead to out-of-plane deformation of graphene, accommodating the plasticity of HEA. The authors also establish a relationship between the mechanical properties of the nanocomposites and the tensile direction and thickness of HEA. These findings are crucial for the design of advanced materials with unprecedented strength and ductility.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Amitava Moitra
Summary: Molecular dynamics simulations were used to investigate the thermal stability of Al-Ni core-shell nanoparticles with different core sizes and shell thicknesses. The study revealed a distinct two-stage melting phenomenon during the continuous heating of these bimetallic nanoparticles. Unlike previous studies, where melting starts from the outer surface and gradually encompasses the core, the results indicated an interface-dominated melting phenomena. The interface-dominated phenomena remained unchanged even with decreased shell thickness, suggesting that interfacial misfit and bond energy orders are the sources of this premelting phenomena.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Ashutosh Rajput, Surajit Kumar Paul
Summary: This study investigates the uniaxial tensile deformation and damage mechanism in single-crystal Aluminum in the presence of soft and hard inclusions. Alterations in mechanical properties were noticed, with softening observed in the presence of Magnesium and hardening in the presence of Titanium. The study provides an understanding of the governing fracture mechanism influenced by the inclusion.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Mechanical
Xiaotao Li, Shenyou Peng, Xu Zhang, Xiaoyu Jiang, Qingyuan Wang
Summary: This study investigates the interaction mechanism between dislocation emission and a crack or a void at both the atomic and continuum scales, revealing that dislocation emission can change the crack growth mode from brittle to ductile and reduce stress concentration near defects.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Materials Science, Multidisciplinary
Nipal Deka, Alexander Stukowski, Ryan B. Sills
Summary: We present a method called Interfacial Line Defect Analysis (ILDA) for identifying and extracting interfacial dislocations and disconnections without requiring detailed input on the nature of the interface. ILDA can provide exact Burgers vectors by only providing the orientations and coherency strains of the crystals at a coherent reference state of the interface. Alternatively, these orientations and strains can be estimated using local atomic deformation gradients, making ILDA fully automated and providing estimated Burgers vectors. ILDA also determines the step height associated with each defect line segment, in case the associated defect is a disconnection. The method relies on the identification of atoms residing at coincidence sites between the two crystals and the construction of a surface mesh connecting these sites to compose Burgers circuits and insert defect line segments. The performance of ILDA is demonstrated in two test cases: a twist grain boundary and a phase boundary.
Article
Chemistry, Physical
Lei Zhang, Gabor Csanyi, Erik van der Giessen, Francesco Maresca
Summary: Predicting atomistic fracture mechanisms in bcc iron is crucial for understanding its semi-brittle nature. By using a Gaussian approximation potential, we developed a model that accurately predicts critical stress intensity factors for different crack systems. Simulations revealed the mechanism of fracture along the original crack plane for {100} and {110} crack planes.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Valery Borovikov, Mikhail I. Mendelev
Summary: The study utilized MD simulation to investigate the effect of edge dislocations on the volume of a preexisting void near grain boundaries in fcc Fe. It was demonstrated that under certain conditions, the void can undergo virtually unlimited growth via this mechanism. This study is the first atomistic simulation to show the feasibility of void growth through this mechanism.
Article
Materials Science, Multidisciplinary
Kiyohiro Yabuuchi, Tomoaki Suzudo
Summary: Irradiation defects in reactor materials lead to degradation of mechanical properties. This study focuses on the relationship between dislocations and defects, specifically investigating the interaction between an edge dislocation and different faceted void geometrical combinations in pure iron. The results reveal the differences in obstacle strength and cutting process between spherical voids and faceted voids, with the highest critical shear stress observed at different regions depending on the faceted void configuration type. The cutting process is influenced by the faceted plane, with the {1101 plane of the faceted void requiring the highest amount of energy to cut the atomic binding.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Chemistry, Physical
Yan-Kun Dou, Han Cao, Xin-Fu He, Jin Gao, Jin-li Cao, Wen Yang
Summary: The interactions between a 1/2 <110> {111} edge dislocation and a void in Fe10Ni20Cr and Fe33Ni33Cr concentrated solid-solution alloys were studied using molecular dynamics simulation. It was found that the dislocation motion becomes more difficult in Fe33Ni33Cr alloy due to larger fluctuations in stacking fault energy compared to Fe10Ni20Cr alloy. However, Fe33Ni33Cr alloy exhibits better irradiation hardening resistance than Fe10Ni20Cr alloy, especially at high temperatures.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Mechanical
Guisen Liu, Kaitao Wu, Ping Yu, Xianhao Cheng, Jiaqing Shi, Changqing Ye, Yong Mao, Yao Shen
Summary: In this study, a void-dislocation interaction model was developed within the framework of dislocation dynamics and implemented in open-source DD software ParaDiS. The model was used to investigate the hardening effects of randomly-distributed voids with different sizes and number densities. The results showed that the average resistance by voids with various sizes is proportional to the 2/3 power of total number density. A modified Friedel-Kroupa-Hirsch (MFKH) model was proposed to quantify the hardening effects of nanometric voids, and it was verified by comparing with experimental data on neutron-irradiated tungsten samples.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Mechanical
Xin-Yao Li, Ya-Fang Guo, Yong Mao, Xiao-Zhi Tang
Summary: The nucleation and growth of {1011} twin in Mg single crystal are investigated through molecular dynamics simulations. The twin embryo is found to be naturally nucleated at the free surface via dislocation slip, and its growth involves the formation of basal stacking faults.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Chemistry, Multidisciplinary
Cecile A. C. Chazot, Behzad Damirchi, Byeongdu Lee, Adri C. T. van Duin, A. John Hart
Summary: Molecularly organized nanocomposites of polymers and carbon nanotubes show great promise as high-performance materials. However, achieving controllable interaction between the polymer and carbon nanotubes remains a challenge. In this study, the researchers successfully coated carbon nanotubes with a conformal coating of meta-aramid, providing insights for future investigation of the mechanical properties of these composites and the application of in situ polymerization to other substrates.
Article
Construction & Building Technology
Zepeng Fan, Fei Pan, Lu Sun, Dawei Wang, Pengfei Liu
Summary: Adhesive failure between bitumen and aggregates is a major issue in pavement cracking and moisture damage. The influence of mineralogy on adhesion properties is studied through molecular dynamics simulations and finite element method. Results show that quartz with bitumen has the best cracking resistance at the molecular scale, and greywacke aggregate exhibits the best cracking resistance at the microscale level. The distribution microstructure of minerals affects the cracking path of the bitumen-aggregate interface.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Chemistry, Physical
Xinghui Wu, Zuozhou Tang, Shuhang Lyu, Qiang Song, Yuanyuan Duan, Zhen Yang
Summary: The effects of particle properties on the nucleation process in a sulfuric acid-water vapor mixture were investigated using molecular dynamics simulation. The study found that an increase in particle-vapor interaction promotes heterogeneous nucleation, and for non-spherical particles, vapor molecules are more prone to heterogeneous nucleation on flat surfaces.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Ping Yu, Guisen Liu, Kaitao Wu, Yanguang Cui, Guannan Zhao, Yao Shen
Summary: Understanding the interaction mechanisms between dislocations and irradiation-induced nanosized voids is critical for predicting the performance of nuclear components. Previous research mostly focused on the first interaction, assuming that already sheared voids have the same hardening effects. Using atomistic simulations, this work studies the interaction mechanisms and corresponding hardening effects between a periodic array of voids and successively incoming dislocations.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Mechanics
Yi Cui, Zengtao Chen, Shaojie Gu, Wenzhi Yang, Yang Ju
Summary: The size dependence of central nanovoid embedded in high-entropy-alloy films under biaxial tension is investigated. It is found that lattice distortion facilitates dislocation emission from the void surface, leading to a decrease in critical stress. Additionally, the grain size variation affects the peak stress in polycrystalline samples, and the failure mechanism differs between monocrystalline and polycrystalline samples.
ARCHIVE OF APPLIED MECHANICS
(2023)
Article
Engineering, Mechanical
Xiao-Yi Wang, Hu-Tian Feng, Chang-Guang Zhou, Zeng-Tao Chen, Jing-Lun Xie
Summary: This paper presents a new degradation model for predicting the preload variation of LMBG, taking into account machining errors. Experimental results show that the model considering machining errors has higher prediction accuracy compared to the model without considering machining errors. Furthermore, the effects of waviness errors, external load, and feed speed on preload degradation were discussed.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Mechanics
Amin Pourasghar, Wenzhi Yang, John Brigham, Zengtao Chen
Summary: This novel study presents a framework to investigate the effects of transient heat conduction on the nonlinear deflection and vibration of single-walled carbon nanotubes (SWCNTs) based on Eringen's nonlocal elasticity and nonlocal heat conduction theories. The differential quadrature method (DQM) is used to solve the transversely induced nonlocal heat conduction. The study explores the effects of thermal waves, boundary conditions, length and radius, etc., on the frequency response of SWCNTs.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Materials Science, Multidisciplinary
Keqiang Hu, Weilin Yang, Jiawei Fu, Zengtao Chen, Cun-Fa Gao
Summary: This paper investigates the behavior of a mode-I crack in a one-dimensional orthorhombic quasicrystal strip under in-plane phonon and phason stress loading. By applying Fourier transforms and solving a system of simultaneous singular integral equations, asymptotic expressions of the stress and displacement fields near the crack tips are obtained. The crack tip singularities and stress intensity factors are analyzed, and the effects of geometric size and crack kinking phenomenon are studied. The influence of the thickness ratio of the cracked strip on stress intensity factors and energy release rates is also investigated.
MATHEMATICS AND MECHANICS OF SOLIDS
(2023)
Article
Mechanics
Weilin Yang, Zengtao Chen
Summary: Recent researches have shown that biomaterials can inspire new microstructural designs for ideal mechanical properties. A brick-and-mortar graded (BM-GRAD) hierarchical arrangement, originating from nacre, is proposed. The cracking mechanism is investigated through theoretical analysis of multiphysical fields, including thermal, stress, and coupled thermal-stress fields. Experimental and numerical results validate the multiphysical model and general solutions of stress and displacement fields. The BM-GRAD microstructure significantly increases the strength under pure stress field, but temperature has a high impact and sudden cooling can cause opening-mode failure. Compared with functional unbrick single gradient (GRAD) design, the BM-GRAD arrangement has the advantage of easier termination of crack propagation.
COMPOSITE STRUCTURES
(2023)
Article
Nanoscience & Nanotechnology
Xiongfeng Hu, Huashen Guan, Zengtao Chen, Xiaofei He, Maoqiu Wang, Shengguan Qu
Summary: Discrete laser surface hardening (DLSH) can create high hardness zones with excellent wear resistance on the surface of ferroalloys. However, the soft subsurface self-tempering zone is unavoidable and harmful to the workpiece. In this study, the microstructure and tensile properties of a martensitic Cr-Ni-Mo alloyed steel were investigated after DLSH and ultrasonic-assisted surface plastic deformation (USPD) treatment. Results showed that the combination of USPD treatment changed the phase, dislocation density, amount of twins, and texture component in the treated surface layer, resulting in improved strength and reduced crack initiation. The DLSH and USPD treatment significantly increased the yield and tensile strength of the material.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Mechanics
Mahsa Nourazar, Weilin Yang, Zengtao Chen
Summary: The study focuses on the mixed-mode problem of a cracked piezoelectric plane under a general in-plane thermal load. The crack is modeled using distributed thermo-mechanical dislocations with unknown density, determined through the Fourier transform method. Solutions for stress, electric displacement, and heat flux in the intact plane under thermal load are obtained. These solutions are then used to formulate singular integral equations for a piezoelectric plane with an arc-shaped crack under thermo-mechanical loading. The integral equations are numerically solved to determine the dislocation density functions along the crack surface, which are used to calculate field intensity factors for the crack. The effect of crack length, crack radius, and distance from the temperature disturbance is investigated under various loading conditions.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Thermodynamics
Wenzhi Yang, Amin Pourasghar, Yi Cui, Liqun Wang, Zengtao Chen
Summary: With the adoption of the non-Fourier dual phase-lag heat conduction theory, this article analyzes the transient thermal process of a cracked strip subjected to ultrafast laser heating. The complex boundary-value problems are reduced to the Cauchy-type singular integral equation using Fourier transform and Laplace transform, and then numerically solved by the Lobatto-Chebyshev technique. The transient temperature characteristics of the cracked strip are graphically displayed to illustrate the effects of the two non-Fourier thermal lags, laser incident position, and Gaussian type heating source.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Mechanics
S. F. Nikrad, Z. T. Chen, A. H. Akbarzadeh
Summary: This research investigates the nonlinear thermal stability responses of functionally graded graphene-reinforced composite (FG-GRC) laminated plates with embedded circular and elliptical delamination as well as edge delamination. The study reveals that the types of graphene distribution pattern and geometry of delamination zones have a substantial effect on the thermal equilibrium paths and buckling temperature of the GRC delaminated plates.
Article
Engineering, Multidisciplinary
Runchao Zhao, Yeyin Xu, Zhitong Li, Zengtao Chen, Zhaobo Chen, Yinghou Jiao
Summary: In this study, a contact model considering the elastoplastic deformation of asperity is established, and the macroscopic contact model of the bolted structure is improved by modifying the skewed distribution function. A dynamic model of the rod fastened rotor-bearing system that incorporates the nonlinear oil film force is established. The influence of preload on the vibration characteristics is analyzed, and the results provide practical guidance for the dynamic design and preload adjustment of gas turbine rod-fastened rotor.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Engineering, Multidisciplinary
Wenzhi Yang, Amin Pourasghar, Zengtao Chen, Xueyang Zhang
Summary: By utilizing the dual-phase-lag theory, this study establishes a theoretical thermoelastic model of a cracked layer in functionally graded materials to unveil the interaction effects of two collinear Griffith cracks under harsh conditions. Numerical calculations evaluate the transient temperature and stress intensity factors, while exploring the influences of crack spacing, nonhomogeneous parameters, and thermal lags on thermal and stress concentrations. The results show significantly higher thermal stress intensity factors at the outer crack tips compared to the inner crack tips, with differences up to 71% and 128% for mode I and II, respectively. These findings suggest a higher risk of fracture with closer adjacent cracks.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Engineering, Mechanical
Runchao Zhao, Zhiqian Zhao, Yeyin Xu, Zhitong Li, Zhaobo Chen, Zengtao Chen, Yinghou Jiao
Summary: A dynamic scaling design strategy for discontinuous bolted rotor systems is proposed, which includes an improved continuous modeling method and parameter mapping relationships between the continuous and the discontinuous structure. The scaling factors of each element of the rotor system are derived by the similarity theory. Experimental and simulation results demonstrate the accuracy of the proposed strategy in predicting the complex dynamic characteristics of the prototype rotor system.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Runchao Zhao, Yeyin Xu, Zhiqian Zhao, Zhitong Li, Zengtao Chen, Zhaobo Chen, Yinghou Jiao
Summary: A multi-scale contact mechanics model considering the whole deformation process of the material was deduced to reflect the contact effect between rotor disks more accurately, and it was verified through experiments. The study found that adjusting the preloads can change the bifurcation state of the rotor system, and increasing the preloads leads to the period-doubling bifurcation phenomenon moving toward low speed, as well as the early appearance of certain combined frequency components. This research provides a theoretical reference for the modeling, dynamic behavior prediction, and fault diagnosis of rod-fastened gas turbine rotor systems.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Civil
S. F. Nikrad, Z. T. Chen, A. H. Akbarzadeh
Summary: The article investigates the nonlinear thermal stability responses of functionally graded graphene-reinforced composite (FG-GRC) laminated plates with delaminations. The three-dimensional crack tip element (3D-CTE) method is used to evaluate the possibility of delamination growth. The influence of delamination configurations and graphene reinforcement distribution patterns on the free vibration of the plates is also evaluated.
THIN-WALLED STRUCTURES
(2023)
Article
Thermodynamics
Xin Lu, Ning Chen, Hui Li, Shiyu Guo, Zengtao Chen
Summary: Porous electrodes have fractal characteristics that are important in the fractional-order system. Heat transfer modes occur simultaneously on the porous electrodes during charging and discharging. A fractional-order heat transfer model is proposed to analyze the time-delay effect in lithium-ion battery modules. The model shows higher simulation accuracy compared to the classical integer-order model.