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Phase field simulation of grain refinement in silver-based filler metal
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作者 朱宇辰 龙伟民 +4 位作者 魏世忠 郭鹏 武汉琦 樊喜刚 魏永强 《China Welding》 CAS 2023年第4期49-54,共6页
Numerical simulation is one of the important auxiliary methods for studying materials-related problems. In this study, phase field simulation was employed to investigate the refinement behavior of BAg55CuZn-x B brazin... Numerical simulation is one of the important auxiliary methods for studying materials-related problems. In this study, phase field simulation was employed to investigate the refinement behavior of BAg55CuZn-x B brazing alloys. Simulation and experimental studies were conducted for B contents ranging from 0 wt.% to 0.2 wt.%. The results demonstrated that the addition of 0.05 wt.% B in the brazing alloy leads to a significant refinement effect. As the B content increases, the grain size further reduces, and a refinement stagnation phenomenon occurs after exceeding 0.15 wt.%. The solidification process of brazing alloys with different B content was predicted by simulation, and the simulation results showed that with the increase of B content, the initial number of nucleation increased, and the radius of the dendrite tip decreased. The simulation results are in good agreement with the experimental findings, providing further evidence of the refining effect of the B element and the reliable predictive capability of the phase field model. 展开更多
关键词 phase field simulation grain refinement silver-based filler metal microstructure
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Flow field simulation and establishment for mathematical models of flow area of spool valve with sloping U-shape notch machined by different methods 被引量:10
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作者 王兆强 顾临怡 +2 位作者 冀宏 陈家旺 李林 《Journal of Central South University》 SCIE EI CAS 2014年第1期140-150,共11页
Precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke was derived. The computational fluid dynamics was used to analyze the flow features of the sloping U-shape not... Precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke was derived. The computational fluid dynamics was used to analyze the flow features of the sloping U-shape notch on the spool, such as mass flow rates, flow coefficients, effiux angles and steady state flow forces under different operating conditions. At last, the reliability of the mathematical model of the flow area for the sloping U-shape notch orifice on the spool was demonstrated by the comparison between the orifice area curve derived and the corresponding experimental data provided by the test. It is presented that the bottom arc of sloping U-shape notch (ABU) should not be omitted when it is required to accurately calculate the orifice area of ABU. Although the theoretical flow area of plain bottom sloping U-shape notch (PBU) is larger than that of ABU at the same opening, the simulated mass flow and experimental flow area of ABU are both larger than these of PBU at the same opening, while the simulated flow force of PBU is larger than that of ABU at the same opening. Therefore, it should be prior to adapt the ABU when designing the spool with proportional character. 展开更多
关键词 spool valve flow field simulation flow area steady state flow force mathematical model sloping U-shape notch
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Coherency matrix-based proper orthogonal decomposition with application to wind field simulation 被引量:7
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作者 胡亮 李黎 +1 位作者 樊剑 方秦汉 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2006年第2期267-272,共6页
Proper Orthogonal Decomposition (POD) provides a powerful modal transformation tool for stochastic dynamics. In this paper, coherency matrix-based proper orthogonal decomposition (CPOD) is presented as an innovati... Proper Orthogonal Decomposition (POD) provides a powerful modal transformation tool for stochastic dynamics. In this paper, coherency matrix-based proper orthogonal decomposition (CPOD) is presented as an innovative form of the POD based on cross power spectral density matrices. By introducing a discretizing scheme, the CPOD-based spectral representation method is obtained for use in stochastic simulation. Moreover, some criteria are proposed that allow the truncation order of CPOD to be conveniently determined. A numerical example to illustrate the application of the proposed method for the simulation of a wind velocity field is provided. 展开更多
关键词 Proper Orthogonal Decomposition coherency matrices order determination criteria wind field simulation
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Structure optimization and flow field simulation of plate type high speed on-off valve 被引量:7
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作者 WANG Xiao-jing LI Wen-jie +1 位作者 LI Chun-hui PENG Yi-wen 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第5期1557-1571,共15页
There is a relatively complex flow state inside the high speed on-off valve,which often produces low pressure area and oil reflux in the high-speed opening and closing process of the spool,causing cavitation and vorte... There is a relatively complex flow state inside the high speed on-off valve,which often produces low pressure area and oil reflux in the high-speed opening and closing process of the spool,causing cavitation and vortex and other phenomena.These phenomena will affect the stability of the internal flow field of the plate valve and the flow characteristics of the high speed on-off valve.Aiming at the problems of small flow rate and instability of internal flow field,a new spool structure was designed.The flow field models of two-hole and three-hole plate spools with different openings were established,and software ANSYS Workbench was chosen to mesh the model.The standard k−εturbulence model was selected for numerical simulation using FLUENT software.The pressure distribution and velocity distribution under the same pressure and different opening degree were obtained.The structure and parameters of the optimization model were also obtained.The stability analysis of flow field under different pressure was carried out.The results demonstrate that the three-hole spool has a similar flow field change with the two-hole spool,but it does not create a low pressure zone,and the three-hole spool can work stably at 2 MPa or less.This method improves the appearance of low pressure area and oil backflow in the process of high speed opening and closing of spool.The stability of flow field and the flow rate of high speed switch valve are improved.Finally,the products designed in this paper are compared with existing hydraulic valve products.The results show that the three-hole plate type high speed on-off valve designed in this paper maintains the stability of the internal flow field under the condition of 200 Hz and large opening degree,and realizes the increase of flow rate. 展开更多
关键词 high speed on-off valve flow field simulation pressure and flow characteristics
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Unconventional phase field simulations of transforming materials with evolving microstructures 被引量:4
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作者 Jiang-Yu Li Chi-Hou Lei +2 位作者 Liang-Jun Li Yi-Chung Shu Yun-Ya Liu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第4期915-927,共13页
Transforming materials with evolving microstructures is one of the most important classes of smart materials that have many potential technological applications, and an unconventional phase field approach based on the... Transforming materials with evolving microstructures is one of the most important classes of smart materials that have many potential technological applications, and an unconventional phase field approach based on the characteristic functions of transforming variants has been developed to simulate the formation and evolution of their microstructures. This approach is advantageous in its explicit material symmetry and energy well structure, minimal number of ma- terial coefficients, and easiness in coupling multiple physical processes and order parameters, and has been applied successfully to study the microstructures and macroscopic prop- erties of shape memory alloys, ferroelectrics, ferromagnetic shape memory alloys, and multiferroic magnetoelectric crys- tals and films with increased complexity. In this topical re- view, the formulation of this unconventional phase field approach will be introduced in details, and its applications to various transforming materials will be discussed. Some ex- amples of specific microstructures will also be presented. 展开更多
关键词 Unconventional phase field simulation Trans- forming materials MICROSTRUCTURES
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Phase field simulation of the 180°domain-switching process in PbTiO_3 single crystal under an antiparallel electric field 被引量:1
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作者 Ping-Li Liu Wu-Yang Chu Li-Jie Qiao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第4期494-499,共6页
The process of 180°domain switching in PbTiO_3 single crystal under an antiparallel electric field was investigated by the three-dimensional phase field simulation,especially the effect of electric field on the t... The process of 180°domain switching in PbTiO_3 single crystal under an antiparallel electric field was investigated by the three-dimensional phase field simulation,especially the effect of electric field on the type and duration of domain switching.It is found that the polarization reversal of domains takes place under an antiparallel electric field in PbTiO_3 single crystal.The results of the phase field simulation indicate that there is only 90°domain switching under a weak electric field.With the rise of the electric field,180°domain switching appears.If the electric field is strengthened further,90°domain switching disappears and the duration of domain switching is shortened. 展开更多
关键词 phase field simulation ferroelectric materials electric field domain switching
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Non-Gaussian Lagrangian Stochastic Model for Wind Field Simulation in the Surface Layer 被引量:1
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作者 Chao LIU Li FU +2 位作者 Dan YANG David R.MILLER Junming WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第1期90-104,共15页
Wind field simulation in the surface layer is often used to manage natural resources in terms of air quality,gene flow(through pollen drift),and plant disease transmission(spore dispersion).Although Lagrangian stochas... Wind field simulation in the surface layer is often used to manage natural resources in terms of air quality,gene flow(through pollen drift),and plant disease transmission(spore dispersion).Although Lagrangian stochastic(LS)models describe stochastic wind behaviors,such models assume that wind velocities follow Gaussian distributions.However,measured surface-layer wind velocities show a strong skewness and kurtosis.This paper presents an improved model,a non-Gaussian LS model,which incorporates controllable non-Gaussian random variables to simulate the targeted non-Gaussian velocity distribution with more accurate skewness and kurtosis.Wind velocity statistics generated by the non-Gaussian model are evaluated by using the field data from the Cooperative Atmospheric Surface Exchange Study,October 1999 experimental dataset and comparing the data with statistics from the original Gaussian model.Results show that the non-Gaussian model improves the wind trajectory simulation by stably producing precise skewness and kurtosis in simulated wind velocities without sacrificing other features of the traditional Gaussian LS model,such as the accuracy in the mean and variance of simulated velocities.This improvement also leads to better accuracy in friction velocity(i.e.,a coupling of three-dimensional velocities).The model can also accommodate various non-Gaussian wind fields and a wide range of skewness–kurtosis combinations.Moreover,improved skewness and kurtosis in the simulated velocity will result in a significantly different dispersion for wind/particle simulations.Thus,the non-Gaussian model is worth applying to wind field simulation in the surface layer. 展开更多
关键词 Lagrangian stochastic model wind field simulation non-Gaussian wind velocity surface layer
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Dynamic self-adaptive ANP algorithm and its application to electric field simulation of aluminum reduction cell 被引量:1
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作者 王雅琳 陈冬冬 +2 位作者 陈晓方 蔡国民 阳春华 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4731-4739,共9页
Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index ... Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index of RP method for the three-dimensional finite element model(FEM) has been given.By taking the electric field of aluminum reduction cell(ARC) as the research object,the performance of two classical RP methods,which are Al-NASRA and NGUYEN partition(ANP) algorithm and the multi-level partition(MLP) method,has been analyzed and compared.The comparison results indicate a sound performance of ANP algorithm,but to large-scale models,the computing time of ANP algorithm increases notably.This is because the ANP algorithm determines only one node based on the minimum weight and just adds the elements connected to the node into the sub-region during each iteration.To obtain the satisfied speed and the precision,an improved dynamic self-adaptive ANP(DSA-ANP) algorithm has been proposed.With consideration of model scale,complexity and sub-RP stage,the improved algorithm adaptively determines the number of nodes and selects those nodes with small enough weight,and then dynamically adds these connected elements.The proposed algorithm has been applied to the finite element analysis(FEA) of the electric field simulation of ARC.Compared with the traditional ANP algorithm,the computational efficiency of the proposed algorithm has been shortened approximately from 260 s to 13 s.This proves the superiority of the improved algorithm on computing time performance. 展开更多
关键词 finite element parallel computing(FEPC) region partition(RP) dynamic self-adaptive ANP(DSA-ANP) algorithm electric field simulation aluminum reduction cell(ARC)
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Analysis of flowout gas field simulations and ignition methods for sulphuric gas wells
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作者 黄平 钱新明 孙文磊 《Journal of Beijing Institute of Technology》 EI CAS 2011年第4期438-444,共7页
To avoid potential human casualties and environmental pollution,flowout gas from sulphuric gas wells showing high concentrations of volatile gas must be neutralized by controlled ignition.Simulation model is built by ... To avoid potential human casualties and environmental pollution,flowout gas from sulphuric gas wells showing high concentrations of volatile gas must be neutralized by controlled ignition.Simulation model is built by using CFD software for flowout gas,and ignition methods are analyzed.The simulation results indicate that the optimal ignition zone is located between 150mm and 570mm above the gas flowout device.Two ignition methods,electronical and chemical,are developed.12 and 6 experimental tests are performed respectively for these two methods.Results from the above tests verify that both approaches are successful in igniting the gas promptly and safely.In addition,our experience proves that the former way is more suitable for the fixed position ignition case,while the latter is more suitable for the long-distance or emergent ignition case.These two approaches can potentially be applied to a wide range of situations other than the fixed position ignition case and long distance ignition case. 展开更多
关键词 sulphuric gas well flowout gas diffusing field simulation electronic ignition chemical ignition
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Research on buffer structure and flow field simulation of swash plate plunger type hydraulic transformer
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作者 WANG Xiaojing HUO Shuhang LI Wenjie 《High Technology Letters》 EI CAS 2022年第4期425-433,共9页
In order to solve the problem of excessive noise and vibration during the operation of the hydraulic transformer,an optimization method of valve plate damping hole structure is proposed to alleviate the phenomenon of ... In order to solve the problem of excessive noise and vibration during the operation of the hydraulic transformer,an optimization method of valve plate damping hole structure is proposed to alleviate the phenomenon of pressure shock.Firstly,the mathematical model of oil pressure gradient in the plunger cavity is established,and the incremental equation of pressure change is derived.Secondly,a kind of buffering structure is proposed,the corresponding relationship between the pressure change and the envelopment angle of the buffering hole and the aperture size is determined by analyzing the oil pressure change curve in the plunger cavity.Finally,the flow field models with buffering holes are established,and the transient simulation of the pressure change process under the optimal solution is carried out with ANSYS software and the flow field pressure distribution contours are obtained.Through the analysis of simulation results,it is concluded that the optimal envelope angle of the three buffer holes ofA-T-B-Ais 5°,and the optimal aperture is 1.8 mm,1.6 mm,and 1.7 mm,respectively.The buffer hole can achieve a better-buffering effect in the range of variable pressure angle[0°,101°].The buffer hole structure can effectively alleviate the pressure shock and reduce the noise level,which lays a foundation for the design and theoretical research of hydraulic transformers. 展开更多
关键词 hydraulic transformer pressure shock buffer structure flow field simulation dynamic grid
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Three-Dimensional Phase Field Simulations of Hysteresis and Butterfly Loops by the Finite Volume Method
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作者 席丽莹 陈焕铭 +3 位作者 郑富 高华 童洋 马治 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期128-131,共4页
Three-dimensional simulations of ferroelectric hysteresis and butterfly loops are carried out based on solving the time dependent Ginzburg-Landau equations using a finite volume method. The influence of externally mec... Three-dimensional simulations of ferroelectric hysteresis and butterfly loops are carried out based on solving the time dependent Ginzburg-Landau equations using a finite volume method. The influence of externally mechanical loadings with a tensile strain and a compressive strain on the hysteresis and butterfly loops is studied numerically. Different from the traditional finite element and finite difference methods, the finite volume method is applicable to simulate the ferroelectric phase transitions and properties of ferroelectric materials even for more realistic and physical problems. 展开更多
关键词 Three-Dimensional Phase field simulations of Hysteresis and Butterfly Loops by the Finite Volume Method
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GPU-accelerated phase field simulation of directional solidification 被引量:1
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作者 GAO Ang HU YanSu +3 位作者 WANG ZhiJun MU DeJun LI JunJie WANG JinCheng 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第6期1191-1197,共7页
The phase field simulation has been actively studied as a powerful method to investigate the microstructural evolution during the solidification.However,it is a great challenge to perform the phase field simulation in... The phase field simulation has been actively studied as a powerful method to investigate the microstructural evolution during the solidification.However,it is a great challenge to perform the phase field simulation in large length and time scale.The developed graphics processing unit(GPU)calculation is used in the phase filed simulation,greatly accelerating the calculation efficiency.The results show that the computation with GPU is about 36 times faster than that with a single Central Processing Unit(CPU)core.It provides the feasibility of the GPU-accelerated phase field simulation on a desktop computer.The GPU-accelerated strategy will bring a new opportunity to the application of phase field simulation. 展开更多
关键词 phase field simulation directional solidification graphics processing unit(GPU) acceleration computer unified device architecture(CUDA) speed-up ratio
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Solvent Property Induced Morphological Changes of ABA Amphiphilic Triblock Copolymer Micelles in Dilute Solution: A Self-consistent Field Simulation Study 被引量:1
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作者 Juan-juan Fan Yuan-yuan Han 崔杰 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2014年第12期1704-1713,共10页
The morphological changes of ABA amphiphilic triblock copolymer micelles in dilute solution were systematically studied by tuning the solvent property using self-consistent field simulation. The solvent property was t... The morphological changes of ABA amphiphilic triblock copolymer micelles in dilute solution were systematically studied by tuning the solvent property using self-consistent field simulation. The solvent property was tuned by changing the Flory-Huggins interaction parameters between each type of blocks and solvent, respectively. The simulation results show that by changing the solvent properties, a series of micelle morphologies such as vesicle, cage-like, ring-shaped, rod-like and spherical micelle morphologies can be obtained. Variations of the free energy of the solution system and the surface area of micelles with the Flory-Huggins interaction parameters were calculated to better understand the effect of solvent property on micelle morphologies. In addition, a phase diagram showing the morphological changes of micelles with the Flory-Huggins interaction parameters is provided. 展开更多
关键词 Solvent property Triblock copolymer Self-consistent field simulation.
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Phase field simulation of solidification under supergravity
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作者 Zhenhua Zhang Xu Hou +2 位作者 Yong Zhang Hua Wei Jie Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2022年第8期102-111,共10页
In order to understand the influence of supergravity on the microstructure of materials,crystal nucleation,dendritic growth,and polycrystal solidification under supergravity are investigated by using the modified nucl... In order to understand the influence of supergravity on the microstructure of materials,crystal nucleation,dendritic growth,and polycrystal solidification under supergravity are investigated by using the modified nucleation theory and phase field models.Firstly,supergravity is considered in the nucleation theory by using pressure-dependent Gibbs free energy.It is found that the critical radius decreases and the nucleation rate increases when supergravity rises.Secondly,anisotropic heat transport is proposed in the phase field model to investigate the influence of supergravity on dendritic growth.Phase field simulations show that supergravity promotes the secondary dendritic growth in the direction parallel to supergravity.Finally,a multiply phase field model with pressure-dependent interfacial energy is employed to simulate the polycrystalline solidification under supergravity.Due to the depth-dependent pressure by supergravity,crystal grains are significantly refined by high pressure.In addition,gradient distribution of grain size is obtained in the solidification morphology of polycrystalline,which is consistent with previous experimental observations.Results of this work suggest that supergravity can be used to tune the microstructures and properties of materials. 展开更多
关键词 Phase field simulation NUCLEATION SOLIDIFICATION SUPERGRAVITY POLYCRYSTAL
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Simulation and analysis of point-source surface wave fields
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作者 Chengyu Sun Xingyao Yin Yunfei Xiao 《Earthquake Science》 CSCD 2011年第5期419-426,共8页
The complexity of near surface intensifies the diversity of seismic wave fields, which makes study on near surface wavefields important in many aspects. The strong absorption of low velocity layer can affect the resol... The complexity of near surface intensifies the diversity of seismic wave fields, which makes study on near surface wavefields important in many aspects. The strong absorption of low velocity layer can affect the resolution of seismic data, and free boundary can cause surface wave. Considering the above problems, we focus on the Rayleigh wavefields simulation using finite-difference wave equation of higher-order staggered grids and PML boundary conditions. Free boundary, buried source and overlying low velocity layer are taken into consideration and point explosion source is adopted. Through some numerical simulation with different parameters, we quantitatively analyze relationship between wave intensity and source depth, as well as the energy variation with propagation and obtain some practical knowledge and conclusions. 展开更多
关键词 near surface point source free boundary Rayleigh wave wave field simulation
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Flow field fusion simulation method based on model features and its application in CRDM
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作者 Si-Tong Ling Wen-Qiang Li +1 位作者 Chuan-Xiao Li Hai Xiang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第3期89-102,共14页
The control rod drive mechanism(CRDM)is an essential part of the control and safety protection system of pressurized water reactors.Current CRDM simulations are mostly performed collectively using a single method,igno... The control rod drive mechanism(CRDM)is an essential part of the control and safety protection system of pressurized water reactors.Current CRDM simulations are mostly performed collectively using a single method,ignoring the influence of multiple motion units and the differences in various features among them,which strongly affect the efficiency and accuracy of the simulations.In this study,we constructed a flow field fusion simulation method based on model features by combining key motion unit analysis and various simulation methods and then applied the method to the CRDM simulation process.CRDM performs motion unit decomposition through the structural hierarchy of function-movement-action method,and the key meta-actions are identified as the nodes in the flow field simulation.We established a fused feature-based multimethod simulation process and processed the simulation methods and data according to the features of the fluid domain space and the structural complexity to obtain the fusion simulation results.Compared to traditional simulation methods and real measurements,the simulation method provides advantages in terms of simulation efficiency and accuracy. 展开更多
关键词 CRDM Flow field simulation Motion unit analysis simulation method fusion
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Simulation of phased array S-scan acoustic field in FSW joint of aluminum alloy extrudate with complex shape
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作者 王常玺 刚铁 《China Welding》 EI CAS 2015年第1期31-36,共6页
The shape of aluminum alloy extrudate used in high-speed train is complex, structural noises from the surfaces of the extrudate will be received when using ultrasonic phased array to detect the flaws in FSW. To solve ... The shape of aluminum alloy extrudate used in high-speed train is complex, structural noises from the surfaces of the extrudate will be received when using ultrasonic phased array to detect the flaws in FSW. To solve this problem, ultrasonic phased array acoustic field model and propagation simulation of acoustic waves were introduced to simulate the acoustic pressure distribution and the propagation of the acoustic waves. With the methods above, the detection parameters can be optimized and as a result, the experimental process can be simplified and the detection efficiency can be improved. Meanwhile, the echoes in the S-scan images can be predicted, which can help analyze the detection results and judge the defects. 展开更多
关键词 aluminum extrudate phased array acoustic field simulation FSW
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NUMERICAL SIMULATION OF TEMPERATURE FIELDS FOR WELD METAL SOLIDIFICATION CRACKING IN STAINLESS STEELS 被引量:5
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作者 R. P. Liu Z. J. Dong and Y. H. Wei( 1)Harbin Research Institute of Welding, Harbin 150080, China 2)National Key Laboratory of Advanced Welding Production Technology, HIT, Harbin 150001, China) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第1期139-144,共6页
This paper has analyzed the influences of the heat input of welding arc, the latent heat of solidifica- tion,fluid flow of liquid metal on the heat conductivity pertaining to welding solidification crack of stainles... This paper has analyzed the influences of the heat input of welding arc, the latent heat of solidifica- tion,fluid flow of liquid metal on the heat conductivity pertaining to welding solidification crack of stainless steels. As a result,two - dimensional heat conduction models with prescribed heat flux mov- ing along the the have been developed that can simulate welding arc, convection and radiation heat loss from top and bottom surfaces of the workpiece. Finally, the finite element model was used to ana- lyze and calculate the temperature field. 展开更多
关键词 stainless steel solidification cracking temperature field mathematical simulation
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Simulation of electromagnetic-flow fields in Mg melt under pulsed magnetic field 被引量:14
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作者 汪彬 杨院生 +1 位作者 马晓平 童文辉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第2期283-288,共6页
The effects of a pulsed magnetic field on the solidified microstructure of pure Mg were investigated.The results show that microstructure of pure Mg is considerably refined via columnar-to-equiaxed growth under the pu... The effects of a pulsed magnetic field on the solidified microstructure of pure Mg were investigated.The results show that microstructure of pure Mg is considerably refined via columnar-to-equiaxed growth under the pulsed magnetic field and the average grain size is refined to 260?? under the optimal processing conditions.A mathematical model was built to describe the interaction of the electromagnetic-flow fields during solidification with ANSYS software.The pulsed electric circuit was first solved and then it is substituted into the magnetic field model.The fluid flow model was solved with the acquired electromagnetic force.The effects of pulse voltage frequency on the current wave and on the distribution of magnetic and flow fields were numerically studied.The pulsed magnetic field increases melt convection,which stirs and fractures the dendritic arms into pieces.These broken pieces are transported into the bulk liquid by the liquid flow and act as nuclei to enhance grain refinement.The Joule heat effect produced by the electric current also participates in the microstructural refinement. 展开更多
关键词 pulsed magnetic field numerical simulation pure Mg microstructure refinement
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Petrel2ANSYS: Accessible software for simulation of crustal stress fields using constraints provided by multiple 3D models employing different types of grids 被引量:6
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作者 LIU Yu-yang PAN Mao LIU Shi-qi 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第9期2447-2463,共17页
Crustal stresses play an important role in both exploration and development in the oil and gas industry.However,it is difficult to simulate crustal stress distributions accurately,because of the incompatibilities that... Crustal stresses play an important role in both exploration and development in the oil and gas industry.However,it is difficult to simulate crustal stress distributions accurately,because of the incompatibilities that exist among different software.Here,a series of algorithms is developed and integrated in the Petrel2ANSYS to carry out two-way conversions between the 3D attribute models that employ corner-point grids used in Petrel and the 3D finite-element grids used in ANSYS.Furthermore,a modified method of simulating stress characteristics and analyzing stress fields using the finite-element method and multiple finely resolved 3D models is proposed.Compared to the traditional finite-element simulation-based approach,which involves describing the heterogeneous within a rock body or sedimentary facies in detail and simulating the stress distribution,the single grid cell-based approach focuses on a greater degree on combining the rock mechanics described by 3D corner-point grid models with the finely resolved material characteristics of 3D finite-element models.Different models that use structured and unstructured grids are verified in Petrel2ANSYS to assess the feasibility.In addition,with minor modifications,platforms based on the present algorithms can be extended to other models to convert corner-point grids to the finite-element grids constructed by other software. 展开更多
关键词 numerical simulation of stress fields corner-point grids finite-element grids PETREL ANSYS
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