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Effect of Process Parameters on the Agglomeration Behavior and Tensile Response of Graphene Reinforced Magnesium Matrix Composites Based on Molecular Dynamics Model
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作者 Chentong Zhao Jiming Zhou +2 位作者 Xujiang Chao Su Wang Lehua Qi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第12期2453-2469,共17页
The mechanical properties of graphene reinforced composites are often hampered by challenges related to the dispersion and aggregation of graphene within the matrix.This paper explores the mechanism of cooling rate,pr... The mechanical properties of graphene reinforced composites are often hampered by challenges related to the dispersion and aggregation of graphene within the matrix.This paper explores the mechanism of cooling rate,process temperature,and process pressure’s influence on the agglomeration behavior of graphene and the tensile response of composites from a computer simulation technology,namely molecular dynamics.Our findings reveal that the cooling rate exerts minimal influence on the tensile response of composites.Conversely,processing temperature significantly affects the degree of graphene aggregation,with higher temperatures leading to the formation of larger-sized graphene clusters.In contrast,processing pressure exhibits negligible impact on the degree of graphene aggregation,and increasing pressure effectively mitigates the formation of large-sized graphene clusters.Moreover,we elucidate the intrinsic factors governing the mechanical response to variations in processing parameters.Notably,we observe that the stretching process facilitates the decomposition of large-sized graphene clusters into smaller ones.This research contributes to the advancement of lightweight metal matrix composites by offering insights into optimizing processing parameters.Additionally,it provides crucial theoretical underpinnings for developing high-performance graphene-reinforced composites. 展开更多
关键词 Agglomeration behavior GNPs/Mg composite tensile response molecular dynamics
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Nonlinear Dynamics Behaviors of a Rotor Roller Bearing System with Radial Clearances and Waviness Considered 被引量:15
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作者 王黎钦 崔立 +1 位作者 郑德志 古乐 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第1期86-96,共11页
A rotor system supported by roller beatings displays very complicated nonlinear behaviors due to nonlinear Hertzian contact forces, radial clearances and bearing waviness. This paper presents nonlinear bearing forces ... A rotor system supported by roller beatings displays very complicated nonlinear behaviors due to nonlinear Hertzian contact forces, radial clearances and bearing waviness. This paper presents nonlinear bearing forces of a roller bearing under four-dimensional loads and establishes 4-DOF dynamics equations of a rotor roller bearing system. The methods of Newmark-β and of Newton-Laphson are used to solve the nonlinear equations. The dynamics behaviors of a rigid rotor system are studied through the bifurcation, the Poincar è maps, the spectrum diagrams and the axis orbit of responses of the system. The results show that the system is liable to undergo instability caused by the quasi-periodic bifurcation, the periodic-doubling bifurcation and chaos routes as the rotational speed increases. Clearances, outer race waviness, inner race waviness, roller waviness, damping, radial forces and unbalanced forces-all these bring a significant influence to bear on the system stability. As the clearance increases, the dynamics behaviors become complicated with the number and the scale of instable regions becoming larger. The vibration frequencies induced by the roller bearing waviness and the orders of the waviness might cause severe vibrations. The system is able to eliminate non-periodic vibration by reasonable choice and optimization of the parameters. 展开更多
关键词 roller bearing rotor system nonlinear bearing force dynamics behaviors BIFURCATION CHAOS
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A semi-analytical pressure and rate transient analysis model for inner boundary and propped fractures exhibiting dynamic behavior under long-term production conditions
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作者 Lin-Song Cheng Chong Cao +4 位作者 Quan-Yu Pan Pin Jia Ren-Yi Cao Zhi-Kai Wang Jun-Jie Shi 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2520-2535,共16页
The loss of hydrocarbon production caused by the dynamic behavior of the inner boundary and propped fractures under long-term production conditions has been widely reported in recent studies.However,the quantitative r... The loss of hydrocarbon production caused by the dynamic behavior of the inner boundary and propped fractures under long-term production conditions has been widely reported in recent studies.However,the quantitative relationships for the variations of the inner boundary and propped fractures have not been determined and incorporated in the semi-analytical models for the pressure and rate transient analysis.This work focuses on describing the variations of the inner boundary and propped fractures and capturing the typical characteristics from the pressure transient curves.A generalized semi-analytical model was developed to characterize the dynamic behavior of the inner boundary and propped fractures under long-term production conditions.The pressure-dependent length shrinkage coefficients,which quantify the length changes of the inner zone and propped fractures,are modified and incorporated into this multi-zone semi-analytical model.With simultaneous numerical iterations and numerical inversions in Laplace and real-time space,the transient solutions to pressure and rate behavior are determined in just a few seconds.The dynamic behavior of the inner boundary and propped fractures on transient pressure curves is divided into five periods:fracture bilinear flow(FR1),dynamic PFs flow(FR2),inner-area linear flow(FR3),dynamic inner boundary flow(FR4),and outer-area dominated linear flow(FR5).The early hump during FR2 period and a positive upward shift during FR4period are captured on the log-log pressure transient curves,reflecting the dynamic behavior of the inner boundary and propped fractures during the long-term production period.The transient pressure behavior will exhibit greater positive upward trend and the flow rate will be lower with the shrinkage of the inner boundary.The pressure derivative curve will be upward earlier as the inner boundary shrinks more rapidly.The lower permeability caused by the closure of un-propped fractures in the inner zone results in greater upward in pressure derivative curves.If the permeability loss for the dynamic behavior of the inner boundary caused by the closure of un-propped fractures is neglected,the flow rate will be overestimated in the later production period. 展开更多
关键词 Semi-analytical model Length shrinkage dynamic behavior Boundary changes Transient behavior
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Effect of diagenetic variation on the static and dynamic mechanical behavior of coral reef limestone
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作者 Linjian Ma Jiajun Deng +3 位作者 Mingyang Wang Jianping Wang Bin Fang Jiawen Wu 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第7期893-908,共16页
Coral reef limestone at different depositional depths and facies differ remarkably on the textural and mineralogical characteristics,owing to the complex sedimentary diagenesis.To explore the effects of pore structure... Coral reef limestone at different depositional depths and facies differ remarkably on the textural and mineralogical characteristics,owing to the complex sedimentary diagenesis.To explore the effects of pore structure and mineral composition associated with diagenetic variation on the mechanical behavior of reef limestone,a series of quasi-static and dynamic compression tests along with microscopic examinations were performed on the reef limestone at shallow and deep burial depths.It is revealed that the shallow reef limestone(SRL)is classified as a porous aragonite-type carbonate rock with high porosity(55.3±3.2)%and pore connectivity.In comparison,the deep reef limestone(DRL)is mainly composed of dense calcite-type calcium carbonate with low porosity(4.9±1.6)%and pore connectivity.The DRL strengthened and stiffened by the tight grain framework consistently displays much higher values of the dynamic compressive strength,elastic modulus,brittleness index,and specific energy absorption than those of the SRL.The gap between two types of limestone further increases with an increase in strain rate.It appears that the failure pattern of SRL is dominated by the inherent defects like weak bonding interfaces and growth lines,revealed by the intricate fracturing network and mixed failure.Likewise,although the preexisting megapores in DRL may affect the crack propagation on pore tips to a certain distance,it hardly alters the axial splitting failure of DRL under impacts.The stress wave propagation and attenuation in SRL is primarily controlled by the reflection and diffusion caused by plenty mesopores,as well as an energy dissipation in layer-wise pore collapse and adjacent grain crushing,while the stress wave in DRL is highly hinged on the insulation and diffraction induced by the isolated megapores.This process is accompanied by the energy dissipation behavior of inelastic deformation resulted from the pore-emanated microcracking. 展开更多
关键词 Reef limestone dynamic behavior Mineral composition Pore structure Wave propagation Energy dissipation
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Experimental and numerical study on dynamic mechanical behaviors of shale under true triaxial compression at high strain rate
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作者 Xiaoping Zhou Linyuan Han +1 位作者 Jing Bi Yundong Shou 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第2期149-165,共17页
High-energy gas fracturing of shale is a novel,high efficacy and eco-friendly mining technique,which is a typical dynamic perturbing behavior.To effectively extract shale gas,it is important to understand the dynamic ... High-energy gas fracturing of shale is a novel,high efficacy and eco-friendly mining technique,which is a typical dynamic perturbing behavior.To effectively extract shale gas,it is important to understand the dynamic mechanical properties of shale.Dynamic experiments on shale subjected to true triaxial compression at different strain rates are first conducted in this research.The dynamic stress-strain curves,peak strain,peak stress and failure modes of shale are investigated.The results of the study indicate that the intermediate principal stress and the minor principal stress have the significant influence on the dynamic mechanical behaviors,although this effect decreases as the strain rate increases.The characteristics of compression-shear failure primarily occur in shale subjected to triaxial compression at high strain rates,which distinguishes it from the fragmentation characteristics observed in shale under dynamic uniaxial compression.Additionally,a numerical three-dimensional Split Hopkinson Pressure Bar(3D-SHPB),which is established by coupling PFC3D and FLAC3D methods,is validated to replicate the laboratory characteristics of shale.The dynamic mechanical characteristics of shale subjected to different confining stresses are systematically investigated by the coupling PFC3D and FLAC3D method.The numerical results are in good agreement with the experimental data. 展开更多
关键词 dynamic behaviors True triaxial compression High strain rates dynamic failure mechanism PFC3D-FLAC3D coupled method
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A molecular dynamics study on mechanical performance and deformation mechanisms in nanotwinned NiCo-based alloys with nano-precipitates under high temperatures
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作者 Zihao Yu Hongyu Wang +2 位作者 Ligang Sun Zhihui Li Linli Zhu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期349-355,共7页
Molecular dynamics simulations are performed to investigate the mechanical behavior of nanotwinned NiCo-based alloys containing coherent L12 nano-precipitates at different temperatures,as well as the interactions betw... Molecular dynamics simulations are performed to investigate the mechanical behavior of nanotwinned NiCo-based alloys containing coherent L12 nano-precipitates at different temperatures,as well as the interactions between the dislocations and nano-precipitates within the nanotwins.The simulation results demonstrate that both the yield stress and flow stress in the nanotwinned NiCo-based alloys with nano-precipitates decrease as the temperature rises,because the higher temperatures lead to the generation of more defects during yielding and lower dislocation density during plastic deformation.Moreover,the coherent L12 phase exhibits excellent thermal stability,which enables the hinderance of dislocation motion at elevated temperatures via the wrapping and cutting mechanisms of dislocations.The synergistic effect of nanotwins and nano-precipitates results in more significant strengthening behavior in the nanotwinned NiCo-based alloys under high temperatures.In addition,the high-temperature mechanical behavior of nanotwinned NiCo-based alloys with nano-precipitates is sensitive to the size and volume fraction of the microstructures.These findings could be helpful for the design of nanotwins and nano-precipitates to improve the high-temperature mechanical properties of NiCo-based alloys. 展开更多
关键词 NiCo-based alloys high temperature nano-precipitate NANOTWINS molecular dynamics simulation mechanical behavior deformation mechanism dislocations
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Molecular dynamics analysis on bending mechanical behavior of alumina nanowires at different loading rates 被引量:3
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作者 Yuxiao James HE Bin MA 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第11期3687-3698,共12页
The molecular dynamics(MD)model ofα-Al_(2)O_(3) nanowires in bending is established by using LAMMPS to calculate the atomic stress and strain at different loading rates in order to study the effect of loading rate on... The molecular dynamics(MD)model ofα-Al_(2)O_(3) nanowires in bending is established by using LAMMPS to calculate the atomic stress and strain at different loading rates in order to study the effect of loading rate on the bending mechanical behaviors of theα-Al_(2)O_(3) nanowires.Research results show that the maximum surface stress−rotation angle curves ofα-Al_(2)O_(3) nanowires at different loading rates are all divided into three stages of elastic deformation,plastic deformation and failure,where the elastic limit point can be determined by the curve symmetry during loading and unloading cycle.The loading rate has great influence on the plastic deformation but little on the elastic modulus ofα-Al_(2)O_(3) nanowires.When the loading rate is increased,the plastic deformation stage is shortened and the material is easier to fail in brittle fracture.Therefore,the elastic limit and the strength limit(determined by the direct and indirect MD simulation methods)are closer to each other.The MD simulation result ofα-Al_(2)O_(3) nanowires is verified to be valid by the good agreement with the improved loop test results.The direct MD method becomes an effective way to determine the elastic limit and the strength limit of nanoscale whiskers failed in brittle or ductile fracture at arbitrary loading rate. 展开更多
关键词 alumina nanowires bending behavior loading rate elastic limit strength limit molecular dynamics
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THE ASYMPTOTIC BEHAVIOR AND OSCILLATION FOR A CLASS OF THIRD-ORDER NONLINEAR DELAY DYNAMIC EQUATIONS
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作者 黄先勇 邓勋环 王其如 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期925-946,共22页
In this paper,we consider a class of third-order nonlinear delay dynamic equations.First,we establish a Kiguradze-type lemma and some useful estimates.Second,we give a sufficient and necessary condition for the existe... In this paper,we consider a class of third-order nonlinear delay dynamic equations.First,we establish a Kiguradze-type lemma and some useful estimates.Second,we give a sufficient and necessary condition for the existence of eventually positive solutions having upper bounds and tending to zero.Third,we obtain new oscillation criteria by employing the Potzsche chain rule.Then,using the generalized Riccati transformation technique and averaging method,we establish the Philos-type oscillation criteria.Surprisingly,the integral value of the Philos-type oscillation criteria,which guarantees that all unbounded solutions oscillate,is greater than θ_(4)(t_(1),T).The results of Theorem 3.5 and Remark 3.6 are novel.Finally,we offer four examples to illustrate our results. 展开更多
关键词 nonlinear delay dynamic equations NONOSCILLATION asymptotic behavior Philostype oscillation criteria generalized Riccati transformation
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MECHANICAL BEHAVIOR OF FCC CRYSTAL SIMULATED BY 3-D DISCRETE DISLOCATION DYNAMICS 被引量:1
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作者 Y.Yu X.X. Pan Y.H. Rong 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2008年第2期94-102,共9页
To simulate the mechanical behavior of the FCC crystal with the lower Peierls stress, the stiff property and physical meaning of the differential equation group consisting of dislocation evolution and mechanical state... To simulate the mechanical behavior of the FCC crystal with the lower Peierls stress, the stiff property and physical meaning of the differential equation group consisting of dislocation evolution and mechanical state was investigated based on the 3-D discrete dislocation dynamics; the results indicate that the differential equation group is serious stiff, namely the external stress changes more quickly than dislocation evolution. Using the established numerical algorithm, the mechanical behavior of FCC crystal was simulated with the dislocations located in the parallel slip planes, and the effect of strain rate on the dislocation configuration and mechanical behavior, and the sat- uration process of mobile dislocation were discussed. The simulation results indicate that the numerical algorithm can efficiently simulate the dislocation dipole and the low strain rate loading. 展开更多
关键词 FCC crystal Mechanical behavior Dislocation dynamics Nu-merical simulation
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Experimental study and numerical simulation of the impact of under-sleeper pads on the dynamic and static mechanical behavior of heavy-haul railway ballast track
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作者 Yihao Chi Hong Xiao +2 位作者 Yang Wang Zhihai Zhang Mahantesh M.Nadakatti 《Railway Engineering Science》 EI 2024年第3期384-400,共17页
Laying the under-sleeper pad(USP)is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload.To explore the impact of application of the USP on the dynamic and static me... Laying the under-sleeper pad(USP)is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload.To explore the impact of application of the USP on the dynamic and static mechanical behavior of the ballast track in the heavy-haul railway system,numerical simulation models of the ballast bed with USP and without USP are presented in this paper by using the discrete element method(DEM)-multi-flexible body dynamic(MFBD)coupling analysis method.The ballast bed support stiffness test and dynamic displacement tests were carried out on the actual operation of a heavy-haul railway line to verify the validity of the models.The results show that using the USP results in a 43.01%reduction in the ballast bed support stiffness and achieves a more uniform distribution of track loads on the sleepers.It effectively reduces the load borne by the sleeper directly under the wheel load,with a 7.89%reduction in the pressure on the sleeper.Furthermore,the laying of the USP changes the lateral resistance sharing ratio of the ballast bed,significantly reducing the stress level of the ballast bed under train loads,with an average stress reduction of 42.19 kPa.It also reduces the plastic displacement of ballast particles and lowers the peak value of rotational angular velocity by about 50%to 70%,which is conducive to slowing down ballast bed settlement deformation and reducing maintenance costs.In summary,laying the USP has a potential value in enhancing the stability and extending the lifespan of the ballast bed in heavy-haul railway systems. 展开更多
关键词 Heavy-haul railway Under-sleeper pad Discrete element method Multi-flexible body dynamic coupling analysis Mechanical behavior Quality state
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Molecular Dynamics Studies on Thermal Behavior of a FAU-type Zeolite
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作者 Ting Jun HOU Ming Juan JI +4 位作者 Hui Liu Xiao Wei Huang Xue Qi Ye Xing Yun Liu Xiao Jie XU (Chemistry Department. Beida-Jiuyuan Molecular Design Laboratory. Peking University. Beijing 100871)(Graduate School of Chinese Academy of Sciences. Beiing 100039) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第6期515-518,共4页
Molecular Dynamics (MD) simulations of siliceous FAU-type zeolite were carried out at various temperatures. to investigate its thermal behaviors. From the study. we found that pure silicon fanjasite showed different t... Molecular Dynamics (MD) simulations of siliceous FAU-type zeolite were carried out at various temperatures. to investigate its thermal behaviors. From the study. we found that pure silicon fanjasite showed different thermal behaviors below 1500K and above 1500K. its cell volume gradually shrinks with the rising of the temperature below 1500K. the cell volume of the zeolite changes little above 1500K. 展开更多
关键词 ZEOLITE molecular dynamics(MD) thermal behavior
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Global Existence,Asymptotic Behavior and Uniform Attractors for a Third Order in Time Dynamics
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作者 曹洁 《Chinese Quarterly Journal of Mathematics》 2016年第3期221-236,共16页
In this paper, a third order(in time) partial differential equation in R^n is con-sidered. By using semigroup method and constructing Lyapunov function, we establish the global existence, asymptotic behavior and uni... In this paper, a third order(in time) partial differential equation in R^n is con-sidered. By using semigroup method and constructing Lyapunov function, we establish the global existence, asymptotic behavior and uniform attractors in nonhomogeneous case. In addition, we also obtain the results of well-uosedness in semilinear case. 展开更多
关键词 third order in time dynamics WELL-POSEDNESS asymptotic behavior uniform attractors
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Understanding the interfacial behaviors of benzene alkylation with butene using chloroaluminate ionic liquid catalyst: A molecular dynamics simulation
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作者 Jialei Sha Chenyi Liu +3 位作者 Zhihong Ma Weizhong Zheng Weizhen Sun Ling Zhao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第2期44-52,共9页
To better understand the benzene alkylation with chloroaluminate ionic liquids(ILs) as catalyst, the interfacial properties between the benzene/butene binary reactants and chloroaluminate ILs with varying cation alkyl... To better understand the benzene alkylation with chloroaluminate ionic liquids(ILs) as catalyst, the interfacial properties between the benzene/butene binary reactants and chloroaluminate ILs with varying cation alkyl chain length and different anions were investigated using molecular dynamics(MD) simulations. The results indicate that ILs can obviously improve the interfacial width, solubility and diffusion of reactants compared to H_(2)SO_(4). The longer alkyl chains of cations present a density enrichment at the interface and protrude into the binary reactants phase. Furthermore, the ILs consisting of 1-octyl-3-methylimidazolium cations([Omim]^(+)) and the stronger acidity heptachlorodialuminate anions([Al_(2)Cl_(7)]^(-)) are more beneficial to promote the interfacial width and facilitate the dissolution and diffusion of benzene in both the IL bulk and the interfacial region in comparison to the ones with shorter alkyl chains cations and weaker acidity anions. The information gives us a better guideline for the design of ILs for benzene alkylation. 展开更多
关键词 Benzene alkylation Interfacial behaviors Ionic liquids Molecular dynamics simulation
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Dynamic Behavior of Lambda-Type Three-Level Atoms and Two-Mode Cavity Field
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作者 HUANG Ting LIN Xiu-Min +1 位作者 CAO Zhuo-Liang GUO Guang-Can 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第4期712-720,共9页
A system comprising of Lambda-type three-level atoms and the two-mode cavity field is considered in this paper. Under the acliabatical approximation and the large detuning condition, the effective Hamiltonian of the s... A system comprising of Lambda-type three-level atoms and the two-mode cavity field is considered in this paper. Under the acliabatical approximation and the large detuning condition, the effective Hamiltonian of the system in the interaction picture can be given out. If the two identical three-level atoms pass through the cavity in turn, the entangled state atoms can be generated. When the interaction time is taken to an appropriate value, the maximally entangled states are created. At the same time, the dynamic behaviors of the system are studied in detail. 展开更多
关键词 entangled atoms dynamic behavior
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Molecular dynamics study on mechanical behaviors of Ti/Ni nanolaminate with a pre-existing void
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作者 Mengjia Su Qiong Deng +3 位作者 Lanting Liu Lianyang Chen He He Yinggang Miao 《Nano Materials Science》 EI CAS CSCD 2022年第2期113-125,共13页
Metallic nanolaminated materials possess excellent mechanical properties due to their unique modulation structures and interfacial properties.However,how microdefects affect their mechanical properties is still uncert... Metallic nanolaminated materials possess excellent mechanical properties due to their unique modulation structures and interfacial properties.However,how microdefects affect their mechanical properties is still uncertain.To evaluate the influences of void location(in the crystalline layer and the Ti/Ni interface),void diameter(d)and thickness of the intermediate layer(h)on overall tensile behaviors,various types of defective Ti/Ni nanolaminates with pre-existing void are established by the molecular dynamics method in this work.The results indicate that the strength and plastic deformation mechanisms are strongly dependent on those determinants.Yield stresses of Ti/Ni nanolaminates decrease distinctly with increasing void diameter,while peak stresses with a void in the crystalline layer decrease with increasing d/h.Different void locations lead eventually to disparate initial plastic deformation carriers around the void,and various evolutions in the microstructure of the defective Ti/Ni nanolaminates.The Ti/Ni interface plays a significant role in the tensile process.The semi-coherent interface impedes new grains and lattice dislocations from passing across the interface,while the incoherent interface facilitates dislocations generating and sliding along the interface,and absorbs the dislocations moving to the interface.The results also indicate that the strain rate significantly affects the evolution of the microstructure and the tensile properties of defective Ti/Ni nanolaminates. 展开更多
关键词 Defective Ti/Ni nanolaminate Pre-existing void INTERFACE Tensile behaviors Molecular dynamics
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Indenter Size Effect on Stress Relaxation Behaviors of Surface-modified Silicon:A Molecular Dynamics Study
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作者 CHEN Juan FANG Liang +2 位作者 CHEN Huiqin SUN Kun HAN Jing 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2022年第3期370-377,共8页
Long-lasting constant loading commonly exists in silicon-based microelectronic contact and can lead to the appearance of plastic deformation.Stress relaxation behaviors of monocrystalline silicon coated with amorphous... Long-lasting constant loading commonly exists in silicon-based microelectronic contact and can lead to the appearance of plastic deformation.Stress relaxation behaviors of monocrystalline silicon coated with amorphous SiO_(2)film during nanoindentation are probed using molecular dynamics simulation by varying the indenter’s size.The results show that the indentation force(stress)declines sharply at the initial and decreases almost linearly toward the end of holding for tested samples.The amount of stress relaxation of SiO_(2)/Si samples indented with different indenters during holding increases with growing indenter size,and the corresponding plastic deformation characteristics are carefully analyzed.The deformation mechanism for confined amorphous SiO_(2)film is depicted based on the amorphous plasticity theories,revealing that the more activated shear transformation zones(STZs)and free volume within indented SiO_(2)film promote stress relaxation.The phase transformation takes place to monocrystalline silicon,the generated atoms of Si-II and bct-5 phases within monocrystalline silicon substrate during holding are much higher than those for smaller indenter. 展开更多
关键词 SiO_(2)/Si bilayer composite stress relaxation behaviors plastic deformation molecular dynamics simulation phase transformation
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Editorial: Special subject on the mechanical behavior of fire dynamics in high-rise buildings
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作者 Jinhua Sun Longhua Hu 《Theoretical & Applied Mechanics Letters》 CAS 2014年第3期61-62,共2页
With rapid economic and social development in China, high-rise buildings have continuously sprung up since 2006. However, several big fire accidents in high-rise buildings such as the Beijing Television Cultural Cente... With rapid economic and social development in China, high-rise buildings have continuously sprung up since 2006. However, several big fire accidents in high-rise buildings such as the Beijing Television Cultural Center fire in 2009 and the Shanghai Jing'an District fire in 2010 etc. have claimed people's lives and caused huge amounts of economic and property losses, 展开更多
关键词 HIGH EDITORIAL Special subject on the mechanical behavior of fire dynamics in high-rise buildings
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Detecting Nonlinear Dynamics Using BDS Test and Surrogate Data in Financial Time Series
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作者 Alex Neri Gutierrez Alexis Rodriguez Carranza Ana Gamarra Carrasco 《Journal of Mathematics and System Science》 2019年第2期46-53,共8页
Physicists experimentalists use many observations of a phenomenon, which are the unknown equations that describe it, in order to understand the dynamics and obtain information on their future behavior. In this article... Physicists experimentalists use many observations of a phenomenon, which are the unknown equations that describe it, in order to understand the dynamics and obtain information on their future behavior. In this article we study the possibility of reproducing the dynamics of the phenomenon using only a measurement scale. The Whitney immersion theorem ideas are presented and generalization of Sauer for fractal sets to rebuild the asymptotic behavior of the phenomena and to investigate evidence of nonlinear dynamics in the reproduced dynamics using the Brock, Dechert, Scheinkman test (BDS). The applications are made in the financial market which are only known stock prices. 展开更多
关键词 NONLINEAR dynamics surrogate DATA bdS TEST and SERIAL TIMES
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The Aysmptotic Behavior of Solution to a Class of Inhomogeneons Systems of Gas Dynamics
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作者 Xie Guiliang (Central South University of Technology Press,Changsha, 410083) 《数学理论与应用》 1999年第2期8-13,共6页
Consider an initial-boundary problem vt - ux=0,u, + ()x + f(u) = ()x,θt+ux=()ux=()x+ (E) v(x,0) = v0(x),u(x,0) = u0(x),θ(0,x) = θ0(x), (I) u(t,0) = u(t,1) = θx(t,0) = θx(t,1) (J... Consider an initial-boundary problem vt - ux=0,u, + ()x + f(u) = ()x,θt+ux=()ux=()x+ (E) v(x,0) = v0(x),u(x,0) = u0(x),θ(0,x) = θ0(x), (I) u(t,0) = u(t,1) = θx(t,0) = θx(t,1) (J) Sufficient and necessary conditions for (E), (I) and (J) to have asymptotic stability of the gobal smooth solution are given by means of the elemental L2 energy method. 展开更多
关键词 exp The Aysmptotic behavior of Solution to a Class of Inhomogeneons Systems of Gas dynamics
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Quasi-static and dynamic tensile behaviors in electron beam welded Ti-6Al-4V alloy
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作者 张静 谭成文 +2 位作者 任宇 王富耻 才鸿年 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第1期39-44,共6页
The quasi-static and dynamic tensile behaviors in electron beam welded(EBW) Ti-6Al-4V alloy were investigated at strain rates of 10-3 and 103 s-1,respectively,by materials test system(MTS) and reconstructive Hopki... The quasi-static and dynamic tensile behaviors in electron beam welded(EBW) Ti-6Al-4V alloy were investigated at strain rates of 10-3 and 103 s-1,respectively,by materials test system(MTS) and reconstructive Hopkinson bars apparatus.The microstructures of the base metal(BM) and the welded metal(WM) were observed with optical microscope.The fracture characteristics of the BM and WM were characterized with scanning electronic microscope.In Ti-6Al-4V alloy joint,the flow stress of WM is higher than that of BM,while the fracture strain of WM is less than that of BM at strain rates of 103 and 10-3 s-1,respectively.The fracture strain of WM has apparent improvement when the strain rate rises from 10-3 to 103 s-1,while the fracture strain of BM almost has no change.At the same time,the fracture mode of WM alters from brittle to ductile fracture,which causes improvement of the fracture strain of WM. 展开更多
关键词 Ti-6Al-4V alloy electron beam welding quasi-static tensile behavior dynamic behavior fracture mode
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