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Breeding design in wheat by combining the QTL information in a GWAS panel with a general genetic map and computer simulation
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作者 Xiaobo Wang Weiwei Mao +5 位作者 Yongfa Wang Hongyao Lou Panfeng Guan Yongming Chen Huiru Peng Jiankang Wang 《The Crop Journal》 SCIE CSCD 2023年第6期1816-1827,共12页
A large amount of genome-wide association study(GWAS)panels together with quantitative-trait locus(QTL)information associated with breeding-targeted traits have been described in wheat(Triticum aestivum L.).However,th... A large amount of genome-wide association study(GWAS)panels together with quantitative-trait locus(QTL)information associated with breeding-targeted traits have been described in wheat(Triticum aestivum L.).However,the application of mapping results from a GWAS panel to conventional wheat breeding remains a challenge.In this study,we first report a general genetic map which was constructed from 44 published linkage maps.It permits the estimation of genetic distances between any two genetic loci with physical map positions,thereby unifying the linkage relationships between QTL,genes,and genomic markers from multiple genetic populations.Second,we describe QTL mapping in a wheat GWAS panel of 688 accessions,identifying 77 QTL associated with 12 yield and grain-quality traits.Because these QTL have known physical map positions,they could be mapped onto the general map.Finally,we present a design approach to wheat breeding by using known QTL information and computer simulation.Potential crosses between parents in the GWAS panel may be evaluated by the relative frequency of the target genotype,trait correlations in simulated progeny populations,and genetic gain of selected progenies.It is possible to simultaneously improve yield and grain quality by suitable parental selection,progeny population size,and progeny selection scheme.Applying the design approach will allow identifying the most promising crosses and selection schemes in advance of the field experiment,increasing predictability and efficiency in wheat breeding. 展开更多
关键词 Wheat breeding Breeding design GWAS panel General genetic map computer simulation
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DEVELOPMENT OF COMPUTER SIMULATION SOFTWAREON PHASE TRANSFORMATION DURING QUENCHING 被引量:5
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作者 L. Chen, W. Xia and X. J. Chen Department of Materials Science and Engineering, Nanchang Institute of Aeronautical Technology, Nanchang 330034, China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第2期618-622,共5页
A computer software to simulate the phase transformation during quenching is designed based on Avrami equation and Scheil additivity principle of incubation period. The isothermal transformation diagrams of supercool... A computer software to simulate the phase transformation during quenching is designed based on Avrami equation and Scheil additivity principle of incubation period. The isothermal transformation diagrams of supercooled austenite are described by cubic spline functions. This software is possess of a good graphic interface of Windows style, can simulate the whole process in austenite decomposition during continuous cooling. If the cooling rate was given, the fraction of various microstructures transformed of austenite decomposition during continuous cooling at any temperature can be calculated. The simulation results are checked with the quenching experiment of 45 steel. The results indicate that the simulation results are comparatively close to the experimental results. 展开更多
关键词 QUENCHING phase transformation computer simulation SOFTWARE
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Comparison of Snellen and Early Treatment Diabetic Retinopathy Study charts using a computer simulation 被引量:5
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作者 Reuben R.Shamir Yael Friedman +2 位作者 Leo Joskowicz Michael Mimouni Eytan Z.Blumenthal 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第1期119-123,共5页
AIM:To compare accuracy,reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study(ETDRS)charts,two main tools used to measure visual acuity(VA).·M ETHODS:A compute... AIM:To compare accuracy,reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study(ETDRS)charts,two main tools used to measure visual acuity(VA).·M ETHODS:A computer simulation was programmed to run multiple virtual patients,each with a unique set of assigned parameters,including VA,false-positive and false-negative error values.For each virtual patient,assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 log MAR units(equivalent to 20/200 to 20/20).Each of 30 000virtual patients were run ten times on each of the two VA charts.·RESULTS:Average test duration(expressed as the total number of characters presented during the test±SD)was12.6±11.1 and 31.2±14.7 characters,for the Snellen and ETDRS,respectively.Accuracy,defined as the absolute difference(±SD)between the assigned VA and the measured VA,expressed in log MAR units,was superior in the ETDRS charts:0.12±0.14 and 0.08±0.08,for the Snellen and ETDRS charts,respectively.Reproducibility,expressed as test-retest variability,was superior in the ETDRS charts:0.23±0.17 and 0.11±0.09 log MAR units,for the Snellen and ETDRS charts,respectively.·CONCLUSION:A comparison of true(assigned)VA to measured VA,demonstrated,on average,better accuracy and reproducibility of the ETDRS chart,but at the penalty of significantly longer test duration.These differences were most pronounced in the low VA range.The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies. 展开更多
关键词 Early Treatment Diabetic RetinopathyStudy Snellen computer simulation visual acuity testing virtual patients
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MATHEMATICAL MODELS OF NITROGEN CONCENTRATION PROFILE OF ION NITRIDED LAYERS AND COMPUTER SIMULATION 被引量:5
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作者 XIA Lifang YAN Mufu Harbin Institute of Technology,Harbin,China Laboratory of Metal Materials and Heat treatment,Harbin Institute of Technology,Harbin,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1989年第7期18-26,共9页
The mathematical models of the kinetics of the layer growth at different ion nitriding condi- tions of armco iron.steels 45,40Cr,42CrMo and 38CrMoAl have been established.Based on these models the expression of nitrog... The mathematical models of the kinetics of the layer growth at different ion nitriding condi- tions of armco iron.steels 45,40Cr,42CrMo and 38CrMoAl have been established.Based on these models the expression of nitrogen concentration profile of ion nitrided layers have been deduced with profile simulating method.They are C_=C_(min)^+(P_4)/(ξ_1-x)+(P_5)/(ξ_(10)~2)(ξ_1-x)~2 C_(γ′)=C_(min)^(γ′)+(P_1)/(ξ_(21))(ξ_2-x)+(P_2)/(ξ_(21)~2)(ξ_2-x)~2 C_α=C_(min)~α+(C_(33))/(C_(33))/(ξ_(32))(ξ_3-x)~3 Using these models,the kinetics of layer growth and the nitrogen concentration profile of ion nitrided layers were sinulated on Apple-Ⅱ computer.Results show that the simulated curves coincide quite well with the experimental data. 展开更多
关键词 computer simulation ion nitriding nitrogen concentration profile
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THEORETICAL PREDICTION OF TOOL-CHIP CONTACT LENGTH IN ORTHOGONAL METAL MACHINING BY COMPUTER SIMULATION 被引量:3
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作者 Gu Lizhi Long Zeming Cao LiwenCollege of Mechanical Engineering, Jiamusi University, Jiamusi 154007, ChinaYuan Zhejun Harbin Institute of Technology 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2002年第3期233-237,共5页
A method for determination of tool-chip contact length is theoreticallypresented in orthogonal metal machining. By using computer simulation and based on the analyses ofthe elastro-plastic deformation with lagrangian ... A method for determination of tool-chip contact length is theoreticallypresented in orthogonal metal machining. By using computer simulation and based on the analyses ofthe elastro-plastic deformation with lagrangian finite element method in the deformation zone, theaccumulated representative length of the low layer, the tool-chip contact length of the chipcontacting the tool rake are calculated, experimental studies are also carried out with 0.2 percentcarbon steel. It is shown that the tool-chip contact lengths obtained from computer simulation havea good agreement with those of measured values. 展开更多
关键词 Tool-chip contact length computer simulation Finite element method Elastro-plastic deformation Representative length of an element
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COMPUTER SIMULATION OF CONTINUOUS ELECTROMAGNETIC STIRRING FOR MAKING RHEOLOGIC SEMI-SOLID SLURRY OF ZL112Y ALUMINUM ALLOY 被引量:2
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作者 LIU Changming YANG Ling ZUO Hongzhi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第6期108-114,共7页
To realize the technology of fabricating the rheologic semi-solid slurry of ZL112Y aluminum alloy via continues electromagnetic stirring process, ANSYS software was used to simulate electromagnetic force field and flu... To realize the technology of fabricating the rheologic semi-solid slurry of ZL112Y aluminum alloy via continues electromagnetic stirring process, ANSYS software was used to simulate electromagnetic force field and fluid velocity field in the alloy melt in a crucible tube in three coils. In the first section of the paper, eletromagnetic force field and fluid velocity field caused by single coil were simulated. The result of this simulation gives an average velocity of 3.2 cm/s and it is called critical velocity because a fluid velocity over it will cause a fine and spherical structure of solid primary a in a semi-solid melt. And, from this result, a reasonable temperature of semi-solid of the alloy and an electrical current intensity were established. The electrical current intensity of the result of this simulation corresponded to the current intensity used in a practice experiment, in which the primary α was obviously refined and sphericized. Based on this simulation of single coil electromagnetic stirring, in the second section of the paper, eletromagnetic force field and fluid velocity field caused by three coils were simulated. The result of the simulation shows that, 1) there is a semi-solid zone of 32 mm from bottom of the crucible tube to the upper; 2) the electrical current intensities of three coils of 400 A, 600 A, and 400 A, which were set to top range, middle range and bottom range of the tube, respectively, were the optimum parameters of electromagnetic current intensity under the condition of this investigation; and 3) under effect of these electromagnetic current intensity, the fluid velocities of the melt in the tube were 6.3 cm/s in top range, 3.75 cm/s in middle range, and 3.9 cm/s in bottom range of it, respectively. 展开更多
关键词 Electromagnetic stirring Electromagnetic force field Fluid velocity field Rheologic semi-solid slurry computer simulation
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Study on Effect of Gd (III) Speciation on Ca (II) Speciationin Human Blood Plasma by Computer Simulation 被引量:2
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作者 Yue WANG Xing LU +4 位作者 Shu Yun WANG Jing Fen HAN Kui Yue YANG Chun Ji NIU Jia Zuan NI 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第2期161-162,共2页
Ca (II) speciation and effect of Gd (III) speciation on Ca (II) speciation in human blood plasma were studied by computer simulation. [CaHCO3](-) is a predominant compound species of Ca (II). Gd (III) can compete with... Ca (II) speciation and effect of Gd (III) speciation on Ca (II) speciation in human blood plasma were studied by computer simulation. [CaHCO3](-) is a predominant compound species of Ca (II). Gd (III) can compete with Ca (II) for biological molecules. The presence of Gd (III) results in a increase of concentration of free Ca (II) and a decrease of concentration of Ca (II) compounds. 展开更多
关键词 SPECIATION blood plasma computer simulation calcium (II) gadolinium (III)
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Computer Simulation of Ferrite Transformation during Hot Working of Low Carbon Steel 被引量:2
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作者 Yunbo XU, Yongmei YU, Xianghua LIU and Guodong WANGState Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110004, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第5期497-500,共4页
On the basis of transformation kinetics and thermodynamics, the austenite-ferrite transformation start temperature during deformation was predicted for several grades of low-carbon steels under different processing co... On the basis of transformation kinetics and thermodynamics, the austenite-ferrite transformation start temperature during deformation was predicted for several grades of low-carbon steels under different processing conditions. Results indicate that Ar3d temperature mostly depended on alloying composition and processing parameters. Ar3d increased as strain rate or strain increased for the same steel grade. In view of enhancement of deformation on transformation, the basic kinetics model was established to simulate deformation induced transformation behavior, using which the influence of the deformation stored energy and effective deformation ledge on the nucleation and growth can be considered. The simulated results are in good agreement with experiment results. 展开更多
关键词 computer simulation Transformation kinetics Ultrafine ferrite Deformation induced transformation
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EXPERIMENTAL INVESTIGATION AND COMPUTER SIMULATION ON DYNAMIC BUCKLING BEHAVIOR OF LIQUID-FILLED CYLINDRICAL SHELLS UNDER AXIAL IMPACT 被引量:2
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作者 Zhang, SY Lei, JP +2 位作者 Zhao, LM Cheng, GQ Lu, GY 《Acta Mechanica Solida Sinica》 SCIE EI 2000年第2期166-172,共7页
This article reports an experimental investigation on the axial impact buckling of thin metallic cylindrical shells fully filled with water. Low velocity impact tests are carried out by DHR-9401 drop hammer rig. The w... This article reports an experimental investigation on the axial impact buckling of thin metallic cylindrical shells fully filled with water. Low velocity impact tests are carried out by DHR-9401 drop hammer rig. The whole process of dynamic buckling is simulated using LS-DYNA computer code. The consistency between experimental observation and numerical simulation is quite satisfactory. The investigation indicates that quite high internal hydrodynamic pressure occurs inside the shell during the impact process. Under the combined action of the high internal pressure and axial compression plastic buckling occurs easily in the thin-walled shells and buckling modes take on regular and axisymmetric wrinkles. 展开更多
关键词 liquid-filled cylindrical shell impact buckling experimental investigation computer simulation
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Computer simulation of the air flow distribution in goaf regarding the use of inert gases and chemical agents 被引量:2
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作者 Waclaw Dziurzyfiski Stanislaw Nawrat 《西安科技大学学报》 CAS 北大核心 2011年第6期755-759,共5页
This paper presents the use of a computer method of the ventilation process simulation for the analysis of the flow distribution of air and gases in the area of wall mining work and the adjacent goaf.In workings and g... This paper presents the use of a computer method of the ventilation process simulation for the analysis of the flow distribution of air and gases in the area of wall mining work and the adjacent goaf.In workings and goaf,the complex issue of the formation of a gaseous atmosphere under variable ventilation conditions and an existing fire hazard level,with the possibility of feeding goaf with an additional carbon dioxide flux as the inertizing agent is considered.Some examples of the simulation of feeding goaf with carbon dioxide illustrating the different patterns of the distribution of the goaf atmosphere gases concentration,said distribution patterns being gas supply place dependent,have been presented.In addition,the impact of the additional sealing of goaf on the distribution level of the concentration of gases,the said sealing made from the wall side with chemical agents has also been considered.The capabilities of the VentGoaf computer simulation program,being the basis for our calculations,enable consideration of the use of the inert gases supplied to the goaf depending on: the location of the gas feeding the pipe outlet,tightness of the fire field,fire centre location,and spatial situation of the mined wall.It has been found that fire prevention elements,such as chemical sealing agents,are of great impact on the effectiveness of fire prevention. 展开更多
关键词 mine ventilation computer simulation inflow of methane and inert gases
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COMPUTER SIMULATION OF EFFECT OF ORIENTATION DIFFERENCE ON MECHANICAL PROPERTIES OF BICRYSTALLINE SPECIMENS 被引量:1
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作者 WEI Chao QIAN Rengen LIN Shi XIAO Jimei University of Science and Technology Beijing,Beijing,China Dept.of Mathematics and Mechanics,University of Science and Technology Beijing,Bijing 100083,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1991年第1期13-16,共4页
Based on the experimental results of the work-hardening processes of single crystals,the ac- commodation processes of polycrvstal deformation and the assumption of idealized polycrystal,the stress-strain relation of e... Based on the experimental results of the work-hardening processes of single crystals,the ac- commodation processes of polycrvstal deformation and the assumption of idealized polycrystal,the stress-strain relation of elasto-plastic deformation crystal was derived.The effect of orientation difference on the mechanical properties of the bicrvstalline specimens of aluminum was simulated by means of the finite element method(FEM)of elasto-plastic crystal.The results are in good agreement with the experimental results made by Clark and Chalmers in 1954. 展开更多
关键词 BICRYSTAL orientation difference grain boundary computer simulation finite element method
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Computer Simulation of Gd(III) Speciation in Human Interstitial Fluid 被引量:1
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作者 Jin Ping +4 位作者 WANG Hai Yuan ZHANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第2期217-218,共2页
The speciation and distribution of Gd(III) in human interstitial fluid was studied by computer simulation. Meantime artificial neural network was applied to the estimation of log ?values of complexes. The results sh... The speciation and distribution of Gd(III) in human interstitial fluid was studied by computer simulation. Meantime artificial neural network was applied to the estimation of log ?values of complexes. The results show that the precipitate species, GdPO4 and Gd2(CO3)3, are the predominant species. Among soluble species, the free Gd(III), [Gd(HSA)] , [Gd(Ox)] and then the ternary complexes of Gd(III) with citrate are main species and [Gd3(OH)4] becomes the predominant species at the Gd(III) total concentration of 2.2?0-2mol/L. 展开更多
关键词 computer simulation gadolinium(III) SPECIATION human interstitial fluid.
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STUDY ON SINGULAR CONFIGURATIONS AND COMPUTER SIMULATION OF 6R ROBOT 被引量:1
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作者 Zhang Kai Hu Dejin Liu Chengliang School of Mechanical Engineering,Shanghai Jiaotong University,Shanghai 200030, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第2期177-180,共4页
When robot is at singular configuration, the limited hand velocity wouldrequire some joints with infeasible speeds so as to lead unsafely of the system. A method of solvingthe approximate velocity of joint near singul... When robot is at singular configuration, the limited hand velocity wouldrequire some joints with infeasible speeds so as to lead unsafely of the system. A method of solvingthe approximate velocity of joint near singular configuration point by adding damped vector isproposed and a modified algorithm is provided. With the analysis of J^(-1) the singularconfigurations of 6R robot are divided into structure boundary singularity , boundary singularity ,inner singularity and wrist singularity. The conditions of singularities of the robot have beenascertained. The computer simulations of the singularities of the robot are developed, which havemany advantages over previous description methods of the singular configurations of robot. With thehelp of boundary singularity analysis, a application in welding trajectory planning checking of therobot has been carried out and the simulation result proved visualized and useful. 展开更多
关键词 ROBOT Singular configuration computer simulation
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Studies on Insoluble Species of Gd(Ⅲ)in Human Blood Plasma by Computer Simulation 被引量:1
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作者 WANG Yue LU Xing +2 位作者 ZHANG Hai-yuan YANG Kui-yueNIU Chun-ji NI Jia-zuan 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2001年第4期352-355,共4页
The insoluble species of Gd ( Ⅲ ) in human blood plasma were investigated by computer simulation. The distribution of the Gd(Ⅲ ) species was obtained. It was found that most of the Gd( Ⅲ ) ions were bound to p... The insoluble species of Gd ( Ⅲ ) in human blood plasma were investigated by computer simulation. The distribution of the Gd(Ⅲ ) species was obtained. It was found that most of the Gd( Ⅲ ) ions were bound to phosphate to form precipitate GdPO4 at the concentration of 1. 000 10-7 mol/L and when the concentration of the Gd (Ⅲ ) increased to 3. 750 X 10-4 mol/L, in excess of the concentration of phosphate, the Gd ( Ⅲ ) ions were bound to carbonate to form another kind of precipitate, Gd2(CO3)3. 展开更多
关键词 SPECIATION Gadolinium ( ) computer simulation
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Computer simulation on the controlled cooling of 82B high-speed rod 被引量:1
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作者 Jinqiao Xu Yazheng Liu Shumei Zhou 《Journal of University of Science and Technology Beijing》 CSCD 2008年第3期330-334,共5页
A modified temperature-phase transformation field coupled nonlinear mathematical model was made and used in computer simulation on the controlled cooling of 82B high-speed rods. The surface temperature history and vol... A modified temperature-phase transformation field coupled nonlinear mathematical model was made and used in computer simulation on the controlled cooling of 82B high-speed rods. The surface temperature history and volume fraction of pearlite as well as the phase transformation history were simulated by using the finite element software Marc/Mentat. The simulated results were compared with the actual measurement and the agreement is good which can validate the presented computational models. 展开更多
关键词 high-speed steel controlled cooling phase transformation computer simulation
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We Are Living in a Computer Simulation 被引量:1
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作者 Ding-Yu Chung 《Journal of Modern Physics》 2016年第10期1210-1227,共18页
This paper posits that we are living in a computer simulation to simulate physical reality which has the same computer simulation process as virtual reality (computer-simulated reality). The computer simulation proces... This paper posits that we are living in a computer simulation to simulate physical reality which has the same computer simulation process as virtual reality (computer-simulated reality). The computer simulation process involves the digital representation of data, the mathematical computation of the digitized data in geometric formation and transformation in space-time, and the selective retention of events in a narrative. Conventional physics cannot explain physical reality clearly, while computer-simulated physics can explain physical reality clearly by using the computer simulation process consisting of the digital representation component, the mathematical computation component, and the selective retention component. For the digital representation component, the three intrinsic data (properties) are rest mass-kinetic energy, electric charge, and spin which are represented by the digital space structure, the digital spin, and the digital electric charge, respectively. The digital representations of rest mass and kinetic energy are 1 as attachment space for the space of matter and 0 as detachment space for the zero-space of matter, respectively, to explain the Higgs field, the reverse Higgs field, quantum mechanics, special relativity, force fields, dark matter, and baryonic matter. The digital representations of the exclusive and the inclusive occupations of positions are 1/2 spin fermion and integer spin boson, respectively, to explain spatial translation by supersymmetry transformation and dark energy. The digital representations of the allowance and the disallowance of irreversible kinetic energy are integral electric charges and fractional electric charges, respectively, to explain the confinements of quarks and quasiparticles. For the mathematical computation component, the mathematical computation involves the reversible multiverse and oscillating M-theory as oscillating membrane-string-particle whose space-time dimension (D) number oscillates between 11D and 10D and between 10D and 4D to explain cosmology. For the selective retention component, gravity, the strong force, electromagnetism, and the weak force are the retained events during the reversible four-stage evolution of our universe, and are unified by the common narrative of the evolution. 展开更多
关键词 computer simulation Physical Reality Virtual Reality Digital computer computer-Simulated Physics Digital Representation Selective Retention M-THEORY Space Structure Higgs Field Reverse Higgs Field Fractional Electric Charge SPIN MULTIVERSE COSMOLOGY Force Fields Cyclic Universe
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Computer Simulation for Effect of Tb^(3+) on Ca^(2+)Speciation in Human Plasma
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作者 卢兴 王悦 +3 位作者 张海元 王进平 牛春吉 倪嘉缵 《Journal of Rare Earths》 SCIE EI CAS CSCD 2002年第3期238-240,共3页
Effect of Tb 3+ on Ca 2+ speciation in human plasma was studied by means of the computer program of MINTEQA2. When Tb 3+ ions are not added into the system, Ca 2+ ions mostly distribute in free Ca ... Effect of Tb 3+ on Ca 2+ speciation in human plasma was studied by means of the computer program of MINTEQA2. When Tb 3+ ions are not added into the system, Ca 2+ ions mostly distribute in free Ca 2+ (74.7%) and the surplus distributes in Ca 2+ complexes, such as [CaHCO 3] +(7.9%), [Ca(Lac)] +(6.4%), CaHPO 4 (1 3%), [CaHistidinateThreoninateH 3] 3+ (2.4%), [CaCitrateHistidinateH 2] (2.3%) and CaCO 3(1.1%). Tb 3+ can compete with Ca 2+ for inorganic as well as biological ligands. An increase of concentration of Tb 3+ in the system results in an increase of content of free Ca 2+ and a decrease of contents of Ca 2+ complexes. 展开更多
关键词 rare earths computer simulation SPECIATION human plasma CALCIUM TERBIUM
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Computer Simulation of the Indentation Creep Tests on Particle-Reinforced Composites
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作者 Zhufeng YUE1,2)1)Department of Engineering Mechanics, Northwestern Polytechnical University, Xi’an 710072, China2)Institute of Materials, Ruhr University, 44780 Bochum, Germany 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2002年第4期335-340,共6页
A systematical simulation has been carried out on the indentation creep test on particle-reinforced composites. The deformation, failure mechanisms and life are analyzed by three reasonable models. The following five ... A systematical simulation has been carried out on the indentation creep test on particle-reinforced composites. The deformation, failure mechanisms and life are analyzed by three reasonable models. The following five factors have been considered simultaneously: creep property of the particle, creep property of the matrix, the shape of the particle, the volume fraction of the particle and the size (relative size to the particle) of the indentation indenter. For all the cases, the power law respecting to the applied stress can be used to model the steady indentation creep depth rate of the indenter, and the detail expressions have been presented. The computer simulation precision is analyzed by the two-phase model and the three-phase model. Two places of the stress concentration are found in the composites. One is ahead of the indentation indenter, where the high stress state is deduced by the edge of the indenter and will decrease rapidly near to a steady value with the creep time. The other one is at the interface, where the high stress state is deduced by the misfit of material properties between the particles and matrix. It has been found that the creep dissipation energy density other than a stress parameter can be used to be the criterion to model the debonding of the interfaces. With the criterion of the critical creep dissipation energy density, a power law to the applied stress with negative exponent can be used to model the failure life deduced by the debonding of interfaces. The influences of the shape of the particles and the matching of creep properties of particle and matrix can be discussed for the failure. With a crack model, the further growth of interface crack is analyzed, and some important experimental phenomena can be predicted. The failure mechanism which the particle will be punched into matrix has been also discussed. The critical differences between the creep properties of the particles and matrix have been calculated, after a parameter has been defined. In the view of competition of failure mechanisms, the best matching of the creep properties of the two phases and the best shape of the particles are discussed for the composite design. 展开更多
关键词 Indentation creep test Particle-reinforced composites computer simulation DEFORMATION FAILURE
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COMPUTER SIMULATION OF CREEP DAMAGE AT CRACK TIP IN SHORT FIBRE COMPOSITES
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作者 张双寅 蔡良武 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1994年第3期282-288,共7页
Creep damage at crack tip in short fibre composites has been sim- ulated by using the finite element method(FEM).The well-known Schapery non- linear viscoelastic constitutive relationship was used to characterize time... Creep damage at crack tip in short fibre composites has been sim- ulated by using the finite element method(FEM).The well-known Schapery non- linear viscoelastic constitutive relationship was used to characterize time-dependent behaviour of the material.A modified recurrence equation was adopted to accelerate the iteration.Kachanov-Rabotnov's damage evolution law was employed.The growth of the damage zone with time around the crack tip was calculated and the results were shown with the so-called 'digit photo',which was produced by the printer. 展开更多
关键词 creep damage VISCO-ELASTICITY finite element method short fibre composite computer simulation
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Computer simulation of interface evolution for an Al-Li alloy during early aging stage
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作者 TANGLiying WANGYongxin +2 位作者 CHENZheng LUYanli ZHANGJianjun 《Rare Metals》 SCIE EI CAS CSCD 2004年第3期279-285,共7页
The nucleation of ordered phase was simulated based on microscopic diffusionequation and the assumptions of the classical nucleation theory were examined. The quantitativecalculations of interface thickness evolution ... The nucleation of ordered phase was simulated based on microscopic diffusionequation and the assumptions of the classical nucleation theory were examined. The quantitativecalculations of interface thickness evolution were accomplished for the first time. It was foundthat the interfaces between ordered phase and disordered matrix were diffuse. The interfacethickness decreased with time, from the initial 1.2 nm to an equilibrium value 0.6 nm. The ratios ofthe radius of ordered particles and the interface thickness monotonously increased, but they wereof the same order of magnitude all the time. The sharp interface assumption should not be adopted inthis stage. For the Al-10% Li (atom fraction) alloy aged at 192℃, the assumptions of the classicalnucleation theory disagreed with the facts. The phase transformation followed the non-classicalnucleation mechanism and the applicable scope of the classical nucleation should be confined. 展开更多
关键词 metal material INTERFACE computer simulation non-classical nucleationtheory
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