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Phase-field study of the second phase particle effect on texture evolution of polycrystalline material 被引量:1
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作者 卢艳丽 张刘超 +1 位作者 周影影 陈铮 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第6期639-643,共5页
The second phase particle effect on texture evolution of polycrystalline material is studied through phase-field method. A unique field variable is introduced into the phase-field model to represent the second phase p... The second phase particle effect on texture evolution of polycrystalline material is studied through phase-field method. A unique field variable is introduced into the phase-field model to represent the second phase particles. Elastic interaction between particles and grains is also considered. Results indicate that in the presence of second phase particles the average particle diameter turns smaller than in the absence of these particles and retards texture formation by pinning effect. The second phase particles change the strain energy profile, which tremendously influences the pinning effect. 展开更多
关键词 texture evolution second phase particles elastic energy phase-field method
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Study of elastic wave propagation in two phase anisotropic media by numerical modeling of pseudospectral method 被引量:5
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作者 刘洋 李承楚 《Acta Seismologica Sinica(English Edition)》 CSCD 2000年第2期143-150,共8页
When there exists anisotropy in underground media elastic parameters of the observed coordinate possibly do not coincide with that of the natural coordinate. According to the theory that the density of potential energ... When there exists anisotropy in underground media elastic parameters of the observed coordinate possibly do not coincide with that of the natural coordinate. According to the theory that the density of potential energy, dissipating energy is independent of the coordinate, the relationship of elastic parameters between two coordinates is derived for two-phase anisotropic media. Then, pseudospectral method to solve wave equations of two-phase anisotropic media is derived. At last, we use this method to simulate wave propagation in two-phase anisotropic media four types of waves are observed in the snapshots, i.e., fast P wave and slow P wave, fast S wave and slow S wave. Shear wave splitting, SV wave cusps and elastic wave reflection and transmission are also observed. 展开更多
关键词 two-phase anisotropy natural coordinate observed coordinate elastic parameters nu merical modeling pseudospectral method
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Phase field modeling of ferroelastic variant switching in yttria-stabilized t'zirconia with strain gradient elasticity and interface tension
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作者 ZHOU QianQian WEI YueGuang +1 位作者 ZHOU YiChun YANG Li 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2024年第5期1443-1457,共15页
The 6–8 wt%yttria-stabilized zirconia with a tetragonal structure(t’-YSZ)is extensively employed in thermal barrier coatings.The exceptional fracture toughness of t’-YSZ can be attributed to its distinctive ferroel... The 6–8 wt%yttria-stabilized zirconia with a tetragonal structure(t’-YSZ)is extensively employed in thermal barrier coatings.The exceptional fracture toughness of t’-YSZ can be attributed to its distinctive ferroelastic toughening mechanism.Microstructure and interface tension play a critical role in ferroelastic variant switching at the micro-and nano-scale.This paper presents an original thermodynamically consistent phase field(PF)theory for analyzing ferroelastic variant switching at the micro-and nano-scale of t’-YSZ.The theory incorporates strain gradient elasticity using higher-order elastic energy and interface tension tensor via geometric nonlinearity to represent biaxial tension resulting from interface energy.Subsequently,a mixed-type formulation is employed to implement the higher-order theory through the finite element method.For an interface in equilibrium,the effects of strain gradient elasticity result in a more uniform distribution of stresses,whereas the presence of interface tension tensor significantly amplifies the stress magnitude at the interface.The introduction of an interface tension tensor increases the maximum value of stress at the interface by a factor of 4 to 10.The nucleation and evolution of variants at a pre-existing crack tip in a mono-phase t’-YSZ have also been studied.The strain gradient elasticity is capable of capturing the size effect of ferroelastic variant switching associated with microstructures in experiments.Specifically,when the grain size approaches that of the specimen,the critical load required for variant switching at the crack tip increases,resulting in greater dissipation of elastic energy during ferroelastic variant switching.Moreover,the interface tension accelerates the evolution of variants.The presented framework exhibits significant potential in modeling ferroelastic variant switching at the micro-and nano-scale. 展开更多
关键词 THERMODYNAMICS strain gradient elasticity interface tension phase field method ferroelastic variant switching
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Simulation of bacterial flagellar phase transition by non-convex and non-local continuum modeling
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作者 Xiaoling Wang,1,a) Yongjun He,2,b) and Qingping Sun 3,c) 1) School of Mechanical Engineering,University of Science and Technology Beijing,Beijing 100083,China 2) UME-MS,ENSTA-ParisTech,Chemin de la Huni`ere,91761 Palaiseau Cedex,France 3) Department of Mechanical Engineering,The Hong Kong University of Science and Technology,Clear Water Bay,Kowloon,Hong Kong,China 《Theoretical & Applied Mechanics Letters》 CAS 2011年第4期74-79,共6页
Bacterial flagellar filament can undergo a stress-induced polymorphic phase transition in both vitro and vivo environments.The filament has 12 different helical forms(phases) characterized by different pitch lengths a... Bacterial flagellar filament can undergo a stress-induced polymorphic phase transition in both vitro and vivo environments.The filament has 12 different helical forms(phases) characterized by different pitch lengths and helix radii.When subjected to the frictional force of flowing fluid,the filament changes between a left-handed normal phase and a right-handed semi-coiled phase via phase nucleation and growth.This paper develops non-local finite element method(FEM) to simulate the phase transition under a displacement-controlled loading condition(controlled helix-twist).The FEM formulation is based on the Ginzburg-Landau theory using a one-dimensional non-convex and non-local continuum model.To describe the processes of the phase nucleation and growth,viscosity-type kinetics is also used.The non-local FEM simulation captures the main features of the phase transition:two-phase coexistence with an interface of finite thickness,phase nucleation and phase growth with interface propagation.The non-local FEM model provides a tool to study the effects of the interfacial energy/thickness and loading conditions on the phase transition. 展开更多
关键词 polymorphic phase transition bacterial flagellar filament GINZBURG-LANDAU non-local elasticity finite element method non-convex viscoelasticity
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Phase-field Modeling of the Influence of Elastic Field on the Nucleation and Microstructure Evolution in Precipitation
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作者 ZHANG Yu-xiang WANG Jin-cheng YANG Yu-juan YANG Gen-cang ZHOU Yao-he 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2007年第2期107-110,共4页
A phase-field method was employed to study the influence of elastic field on the nucleation and microstructure evolution. Two kinds of nucleation process were considered: one using fixed nucleation probability and th... A phase-field method was employed to study the influence of elastic field on the nucleation and microstructure evolution. Two kinds of nucleation process were considered: one using fixed nucleation probability and the other calculated from the classical nucleation theory. In the latter case, the simulated results show that the anisotropic elastic strain field yields significant effects on the behavior of nucleation. With a large lattice misfit between the matrixes and the precipitates, the nucleation process does not appear fully random but displays some spatial correlation and has a preference for the elastic soft direction. However, with a small lattice misfit, this bias does not look quite clear. On the contrary, in the case of fixed nucleation probability, the elastic field has no influence on the nucleation process. The lattice mismatch also exerts influences on the microstructure morphology: with lattice mismatch becoming larger, the microstructure proves to align along the elastic soft direction. 展开更多
关键词 elastic field NUCLEATION phase-field method PRECIPITATION
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First principles study of structural, electronic and mechanical properties of transition metal hydrides(TMH, TM=Mo,Tc, Ru) 被引量:3
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作者 G. SUDHA PRIYANGA A.T.ASVINI MEENAATCI +1 位作者 R. RAJESWARA PALANICHAMY K.IYAKUTTI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第9期2700-2707,共8页
The structural, electronic and mechanical properties of transition metal hydrides (TMH, TM=Mo, Tc, Ru) are investigated by means of first principles calculation based on density fimctional theory with generalized gr... The structural, electronic and mechanical properties of transition metal hydrides (TMH, TM=Mo, Tc, Ru) are investigated by means of first principles calculation based on density fimctional theory with generalized gradient approximation. Among the five crystallographic structures that have been investigated, the cubic phase is found to be more stable than the hexagonal ones. A structural phase transition from ZB to WC in Moll, NaC1 to NiAs in TcH and NaCI to ZB to NiAs in RuH is also predicted under high pressure. The calculated elastic constants indicate that all the three hydrides are mechanically stable at ambient pressure. 展开更多
关键词 ab-initio method structural phase transition electronic properties elastic property
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Calculation of scattering parameters for ultracold ~6 Li-~7 Li elastic collisions
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作者 张计才 孙金锋 刘玉芳 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第2期216-219,共4页
This paper theoretically studies the elastic scattering properties in a mixture of 6Li and 7Li atoms at cold and ultracold temperatures. Based on the constructed accurate interatomic potential of the triplet state for... This paper theoretically studies the elastic scattering properties in a mixture of 6Li and 7Li atoms at cold and ultracold temperatures. Based on the constructed accurate interatomic potential of the triplet state for 6Li7Li mixture by the mass scaling method, it calculates the interspecies s-wave scattering lengths and the p-wave scattering lengths by the variable phase method and the semiclassical method, respectively. The scattering length is in good agreement with the experiment. The partial-wave and total cross sections are also calculated and a rich resonance structure is found. 展开更多
关键词 scattering length elastic cross section variable phase method
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Calculation of the elastic collision properties of Na and Li atoms at ultracold temperature
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作者 张计才 张莹 +1 位作者 杜丙阁 孙金锋 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1486-1490,共5页
This paper firstly reports a theoretical study of elastic scattering properties in a mixture of 23Na and 7Li atoms at cold and ultracold temperatures in detail. Based on the new constructed accurate singlet X1∑g+ an... This paper firstly reports a theoretical study of elastic scattering properties in a mixture of 23Na and 7Li atoms at cold and ultracold temperatures in detail. Based on the new constructed accurate singlet X1∑g+ and the triplet a3∑u+ states interatomic potentials for 23Na7Li mixture, it calculates the scattering lengths and the effective ranges by three computational methods, and obtains good agreements. Using the mass scaling method, it also calculates 23Na6Li scattering lengths and s-wave and total elastic cross sections, whose rich resonance structures were found and interpreted in terms of quasibound diatomic levels trapped behind a centrifugal barrier. 展开更多
关键词 scattering length elastic cross section variable phase method
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P-and S-wavefield simulations using both the firstand second-order separated wave equations through a high-order staggered grid finite-difference method
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作者 Chao-ying Bai Xin Wang Cai-xia Wang 《Earthquake Science》 2013年第2期83-98,共16页
In seismic exploration, it is common practice to separate the P-wavefield from the S-wavefield by the elastic wavefield decomposition technique, for imaging purposes. However, it is sometimes difficult to achieve this... In seismic exploration, it is common practice to separate the P-wavefield from the S-wavefield by the elastic wavefield decomposition technique, for imaging purposes. However, it is sometimes difficult to achieve this, especially when the velocity field is complex. A useful approach in multi-component analysis and modeling is to directly solve the elastic wave equations for the pure P- or S-wavefields, referred as the separate elastic wave equa- tions. In this study, we compare two kinds of such wave equations: the first-order (velocity-stress) and the second- order (displacement-stress) separate elastic wave equa- tions, with the first-order (velocity-stress) and the second- order (displacement-stress) full (or mixed) elastic wave equations using a high-order staggered grid finite-differ- ence method. Comparisons are given of wavefield snap- shots, common-source gather seismic sections, and individual synthetic seismogram. The simulation tests show that equivalent results can be obtained, regardless of whether the first-order or second-order separate elastic wave equations are used for obtaining the pure P- or S-wavefield. The stacked pure P- and S-wavefields are equal to the mixed wave fields calculated using the corre- sponding first-order or second-order full elastic wave equations. These mixed equations are computationallyslightly less expensive than solving the separate equations. The attraction of the separate equations is that they achieve separated P- and S-wavefields which can be used to test the efficacy of wave decomposition procedures in multi-com- ponent processing. The second-order separate elastic wave equations are a good choice because they offer information on the pure P-wave or S-wave displacements. 展开更多
关键词 Finite-difference method Staggeredgrid First-order separate elastic wave equation second-order separate elastic wave equation Multiple arrival tracking
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Theoretical Study of the Nuclear Charge Distributions of Tin Isotopes
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作者 刘健 褚衍运 任中洲 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第7期614-618,共5页
Nuclear binding energies, charge radii and the charge distributions of even-even tin (Sn) isotopes are calculated using relativistic mean field theory, and the theoretical results are found to be in accordance with ... Nuclear binding energies, charge radii and the charge distributions of even-even tin (Sn) isotopes are calculated using relativistic mean field theory, and the theoretical results are found to be in accordance with the experimental data. The nuclear charge form factors for Sn isotopes are calculated using the phase-shift analysis method. It is shown that the minima of the charge form factors shift upward and inward with an increase in the neutron number of the Sn isotopes. 展开更多
关键词 elastic electron-nucleus scattering relativistic mean-field theory phase-shift analysis method nuclear charge form factor
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气井定产量和变产量弹性二相法的通式及应用
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作者 陈元千 刘洋 王鑫 《油气地质与采收率》 CAS CSCD 北大核心 2024年第1期72-77,共6页
对于受封闭边界控制的气体流动,当气井完成试气和关井取得原始地层压力之后,若以某稳定产量开井生产,测试的井底流压的压降曲线,根据压力动态的变化特征,可划分为非稳态阶段、过渡阶段和拟稳态阶段。其中的拟稳态阶段,称为弹性二相法阶... 对于受封闭边界控制的气体流动,当气井完成试气和关井取得原始地层压力之后,若以某稳定产量开井生产,测试的井底流压的压降曲线,根据压力动态的变化特征,可划分为非稳态阶段、过渡阶段和拟稳态阶段。其中的拟稳态阶段,称为弹性二相法阶段。在弹性二相法阶段的井控范围内,井底流压呈等速下降。本文基于陈元千提出的压力一次方、压力平方和拟压力表示的定产量弹性二相法,以及基于Blasingame提出的压力一次方表示的变产量弹性二相法,分别建立了气井定产量和变产量弹性二相法的通式。通过实例的应用表明,两个通式是实用有效的。 展开更多
关键词 气井 定产量 变产量 拟压力 压力一次方 压力平方 弹性二相法
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气井拟压力弹性二相法的推导、简化及应用
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作者 陈元千 刘洋 《油气藏评价与开发》 CSCD 北大核心 2024年第3期317-323,共7页
弹性二相法是评价气井控制原始地质储量的动态法,又称为拟稳态法(pseudo-steady-state method)或气藏范围测试法(reservoir limit testing method)。该法主要用于气井初期测试,评价岩性、断块和裂缝类型气藏井控的原始地质储量。由压力... 弹性二相法是评价气井控制原始地质储量的动态法,又称为拟稳态法(pseudo-steady-state method)或气藏范围测试法(reservoir limit testing method)。该法主要用于气井初期测试,评价岩性、断块和裂缝类型气藏井控的原始地质储量。由压力平方表示的弹性二相法,在中国从1994年起,连续4次被列入国家油气行业标准(SY/T 6098—1994,SY/T 6098—2000,SY/T 6098—2010,SY/T 6098—2022)。与拟压力表示的弹性二相法相比,由压力平方表示的弹性二相法是一种较好的近似评价方法。利用AL-HUSSAINY(1966)指出的拟压力关系式,经理论推导,得到了拟压力的弹性二相法,并应用WATTENBARGER(1968)对µgZ随p的变化关系研究,对拟压力弹性二相法进行了简化,分别得到了由压力一次方和压力平方表示的弹性二相法。目前,在国内外的文献中,尚看不到有关拟压力弹性二相法推导的报道。通过实例应用表明,压力一次方表示的弹性二相法评价的井控原始地质储量明显偏低,而由压力平方表示的弹性二相法评价的结果明显偏高。 展开更多
关键词 气井 拟压力 压力一次方 压力平方 弹性二相法 推导 简化 应用
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气井拟压力弹性一相法的推导、简化及应用
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作者 陈元千 《油气地质与采收率》 CAS CSCD 北大核心 2024年第6期89-95,共7页
对于一口处在封闭边界之内的新气井,以某稳定产量开井生产,进行了压降曲线测试。从理论上讲,又可将压降曲线按其压力动态划分为非稳态阶段、过渡阶段(又称为非稳态阶段的后期)和拟稳态阶段。所谓非稳态阶段,是指气井压降漏斗的外缘半径... 对于一口处在封闭边界之内的新气井,以某稳定产量开井生产,进行了压降曲线测试。从理论上讲,又可将压降曲线按其压力动态划分为非稳态阶段、过渡阶段(又称为非稳态阶段的后期)和拟稳态阶段。所谓非稳态阶段,是指气井压降漏斗的外缘半径,尚未达到边界之前的范围。而所谓过渡阶段,是指由非稳态阶段过渡到拟稳态阶段的范围。对于拟稳态阶段,我国称为弹性二相法,可用于确定气井控制的原始地质储量。该法被连续四次列于国家油气的行业标准。对于非稳态阶段,本文基于达西定律的平面径向流微分式,利用AI-Hussainy提出的拟压力函数,经推导得到了拟压力的弹性一相法。利用该法可以评价气藏的有效渗透率和井的总表皮系数。同时,利用Wattenbarger对拟压力函数性质的研究结果,通过简化得到了由压力一次方和压力平方表示的弹性一相法。通过实例应用结果表示,三种方法评价的结果是一致的。 展开更多
关键词 气井 弹性一相法 拟压力 压力一次方 压力平方 有效渗透率 总表皮系数
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Hf含量对湿化学法制备超细W-Y_(2)O_(3)复合材料显微组织与性能的影响 被引量:1
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作者 刘祯 颜硕 +2 位作者 罗来马 昝祥 吴玉程 《中国有色金属学报》 EI CAS CSCD 北大核心 2024年第1期125-138,共14页
本文在现有W-Y_(2)O_(3)材料基础上,引入微量Hf4+掺杂入Y_(2)O_(3),调节Y_(2)O_(3)与W晶粒之间的界面关系,从而改善W基材料的综合性能。通过改变Y与Hf元素的掺杂比例,获得纳米级W基复合粉体,在氢气气氛下常规烧结制备W-Y_(2)(Hf)O_(3)... 本文在现有W-Y_(2)O_(3)材料基础上,引入微量Hf4+掺杂入Y_(2)O_(3),调节Y_(2)O_(3)与W晶粒之间的界面关系,从而改善W基材料的综合性能。通过改变Y与Hf元素的掺杂比例,获得纳米级W基复合粉体,在氢气气氛下常规烧结制备W-Y_(2)(Hf)O_(3)复合材料。采用SEM、TEM等表征手段对W-Y_(2)(Hf)O_(3)复合材料的性能进行表征分析,研究Y与Hf元素在材料中的作用规律。结果表明:掺杂Hf元素有利于后续氢气还原,在第二相掺杂量不变条件下,当Hf含量增加时,所获得的粉体粒径减小,W-3Y-7Hf的粒径约为100 nm,明显小于传统制备的W-Y_(2)O_(3)粉体。烧结后的块体晶粒尺寸细化,显微硬度和相对密度随之增大,成分为W-3Y-7Hf烧结块体显微硬度最高,为513.7HV_(0.2),致密度为97.6%。在钨基材料中同时添加Y与Hf元素会在钨晶粒的晶界与晶内处形成复合第二相氧化物Y_(2)Hf_(2)O_(7)颗粒,尺寸更小,弥散强化作用更强;其中,W-3Y-7Hf中第二相氧化物颗粒尺寸仅为200 nm左右,与钨晶界产生良好的界面结合关系,形成半共格界面。 展开更多
关键词 纳米级钨基复合粉体 湿化学法 弥散强化 复合第二相氧化物
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实时周跳探测与修复的MGF周跳解算方法的改进
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作者 申运炎 李克昭 +4 位作者 杨梦瑶 焦迎香 田晨冬 王凯 岳哲 《测绘工程》 2024年第3期14-25,共12页
周跳的探测和修复是基于载波相位高精度定位的关键技术之一。基于改进的几何无关相位组合MGF方法具有直接分离不同频率上的周跳,对高频数据中较小的周跳实现有效探测,探测速度远快于TurboEdit法等优点。但MGF法无法探测4周以上的周跳,... 周跳的探测和修复是基于载波相位高精度定位的关键技术之一。基于改进的几何无关相位组合MGF方法具有直接分离不同频率上的周跳,对高频数据中较小的周跳实现有效探测,探测速度远快于TurboEdit法等优点。但MGF法无法探测4周以上的周跳,并对低采样率和低卫星高度角下的数据进行周跳探测时,会选取错误的周跳备选值作为周跳检验量从而造成周跳的误判。针对MGF法所存在的问题,通过联合相位减伪距法PRP法,构建新的周跳备选值判断方程,并对MGF法的周跳检验量进行二次历元间差分STMGF,组成PRP-STMGF周跳探测组合。PRP-STMGF周跳探测组合能够探测任意周的周跳,与TurboEdit法相比,修复时无需分离周跳,直接对PRP-STMGF法的周跳检验量进行四舍五入即可确定出正确的周跳值,且适用于低采样率和低卫星高度角下的实时周跳探测与修复。最后通过北斗双频实测数据进行实验验证,结果表明,PRP-STMGF周跳探测组合,避免了MGF法选取错误周跳备选值的问题,相较于TurboEdit法不仅低延时,准确率高,且适用于不同采样率和低卫星高度角下周跳探测与修复。 展开更多
关键词 周跳 改进的几何无关相位组合 相位减伪距法 二次历元间差分
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Tungsten nanoparticle-strengthened copper composite prepared by a sol–gel method and in-situ reaction 被引量:2
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作者 Tian-xing Lu Cun-guang Chen +2 位作者 Zhi-meng Guo Pei Li Ming-xing Guo 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第11期1477-1483,共7页
Tungsten nanoparticle-strengthened Cu composites were prepared from nanopowder synthesized by a sol–gel method and in-situ hydrogen reduction.The tungsten particles in the Cu matrix were well-dispersed with an averag... Tungsten nanoparticle-strengthened Cu composites were prepared from nanopowder synthesized by a sol–gel method and in-situ hydrogen reduction.The tungsten particles in the Cu matrix were well-dispersed with an average size of approximately 100–200 nm.The addition of nanosized W particles remarkably improves the mechanical properties,while the electrical conductivity did not substantially decrease.The Cu–W composite with 6 wt%W has the most comprehensive properties with an ultimate strength of 310 MPa,yield strength of 238 MPa,hardness of HV 108 and electrical conductivity of 90%IACS.The enhanced mechanical property and only a small loss of electrical conductivity demonstrate the potential of this new strategy to prepare W nanoparticle-strengthened Cu composites. 展开更多
关键词 COPPER composites second phase strengthening TUNGSTEN sol–gel method
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气井变产量弹性二相法的应用 被引量:2
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作者 陈元千 王鑫 《油气地质与采收率》 CAS CSCD 北大核心 2023年第5期63-66,共4页
对于一口新气井,在气井产量保持稳定的条件下进行井底流压的压降曲线测试是一项重要的工作。气井的压降曲线分为非稳定阶段、过渡阶段和拟稳定阶段。其中非稳定阶段又称为弹性一相,拟稳定阶段称为弹性二相。前者的测试资料可用于确定气... 对于一口新气井,在气井产量保持稳定的条件下进行井底流压的压降曲线测试是一项重要的工作。气井的压降曲线分为非稳定阶段、过渡阶段和拟稳定阶段。其中非稳定阶段又称为弹性一相,拟稳定阶段称为弹性二相。前者的测试资料可用于确定气层的有效渗透率和气井的表皮系数,后者的测试资料主要用于评估气井控制的原始地质储量。然而,对于致密低渗透气层,气井压裂后的产量不能保持稳定,而是处于递减状态。本文提出了由压力一次方和压力二次方分别表示的变产量压降曲线拟稳定阶段的弹性二相法关系式,可用于评估定容气藏的原始地质储量。实例应用表明2种方法实用有效且评估结果基本相同。 展开更多
关键词 气井 变产量 拟稳定阶段 弹性二相法 应用 评估
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An explicit finite element method for dynamic analysis in three-medium coupling system and its application
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作者 赵成刚 李伟华 +1 位作者 王进廷 李亮 《Acta Seismologica Sinica(English Edition)》 CSCD 2003年第3期272-282,共11页
In this paper, an explicit finite element method to analyze the dynamic responses of three-medium coupled systems with any terrain is developed on the basis of the numerical simulation of the continuous conditions on ... In this paper, an explicit finite element method to analyze the dynamic responses of three-medium coupled systems with any terrain is developed on the basis of the numerical simulation of the continuous conditions on the bounda-ries among fluid saturated porous medium, elastic single-phase medium and ideal fluid medium. This method is a very effective one with the characteristic of high calculating speed and small memory needed because the formulae for this explicit finite element method have the characteristic of decoupling, and which does not need to solve sys-tem of linear equations. The method is applied to analyze the dynamic response of a reservoir with considering the dynamic interactions among water, dam, sediment and basement rock. The vertical displacement at the top point of the dam is calculated and some conclusions are given. 展开更多
关键词 fluid saturated porous medium-elastic single-phase medium-ideal fluid medium coupled system dynamic response analysis explicit finite element method
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弹性二相法新式的推导及应用 被引量:3
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作者 陈元千 石晓敏 《油气藏评价与开发》 CSCD 2023年第2期135-140,共6页
对于定容封闭气藏,当气井以稳定产量开井生产后,根据井底流动压力与时间的变化动态,可划分为非稳定阶段、过渡阶段和拟稳定阶段。其中的非稳定阶段称为弹性一相阶段,拟稳定阶段称为弹性二相阶段。后者是评价气井控制原始地质储量(OGIP)... 对于定容封闭气藏,当气井以稳定产量开井生产后,根据井底流动压力与时间的变化动态,可划分为非稳定阶段、过渡阶段和拟稳定阶段。其中的非稳定阶段称为弹性一相阶段,拟稳定阶段称为弹性二相阶段。后者是评价气井控制原始地质储量(OGIP)的重要方法。陈元千于1991年提出的拟稳定阶段的弹性二相法,在中国得到了广泛的重视和应用,被连续多次列于中华人民共和国石油天然气行业标准。基于在有限封闭边界气藏内,一口以稳定产量生产的气井,考虑天然气、岩石和束缚水的弱弹性膨胀作用的扩散方程,经推导得到了由井底流动压力与累积产量表示的拟稳定阶段弹性二相法的新式。该式可用于评价气井控制的原始地质储量(OGIP),它优越于由井底流动压力与时间关系表示的原式,克服了因产量波动对评价结果造成的影响。通过实测应用表明,弹性二相法的新式是实用有效的。 展开更多
关键词 定容封闭气藏 拟稳定阶段 弹性二相法 原始地质储量 新式 推导 应用
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相场法研究Al_(x)CuMnNiFe高熵合金富Cu相析出机理
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作者 王凯乐 杨文奎 +2 位作者 史新成 侯华 赵宇宏 《物理学报》 SCIE EI CAS CSCD 北大核心 2023年第7期313-327,共15页
BCC(体心立方)和FCC(面心立方)结构共存的高熵合金通常具有优异的综合力学性能,Al元素可以促进含Cu高熵合金由FCC向BCC结构转变.本文基于Chan-Hilliard方程和Allen-Cahn方程,建立Al_(x)CuMnNiFe高熵合金三维相场模型,模拟了Al_(x)CuMnN... BCC(体心立方)和FCC(面心立方)结构共存的高熵合金通常具有优异的综合力学性能,Al元素可以促进含Cu高熵合金由FCC向BCC结构转变.本文基于Chan-Hilliard方程和Allen-Cahn方程,建立Al_(x)CuMnNiFe高熵合金三维相场模型,模拟了Al_(x)CuMnNiFe高熵合金(x=0.4,0.5,0.6,0.7)在823 K等温时效时纳米富Cu相的微观演化过程.结果表明,Al_(x)CuMnNiFe高熵合金时效时会产生两种复杂核壳结构:富Cu核/B2_(s)壳以及B2_(c)核/FeMn壳,通过讨论分析发现形成的B2_(c)对纳米富Cu相的形成起到抑制作用,这种抑制作用随着Al元素的增加而变大;结合经验公式做出Al_(x)CuMnNiFe高熵合金富Cu相的屈服强度随时效时间的变化曲线,得到峰值屈服强度的时效时间和合金体系,可以为时效工艺提供参考. 展开更多
关键词 相场法 高熵合金 富Cu相 弹性能
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