欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
提出了一种针对超细晶和纳米晶金属（主要是fcc金属）晶间断裂的微结构计算模型，即采用基于机制的应变梯度塑性（CMSG）理论描述晶粒内部材料塑性变形过程中的变形、强化和尺度效应；采用黏聚力界面模型来模拟晶界的滑移和分离现象，以及晶间裂纹的萌生和演化，直至晶间断裂导致的材料失效．利用该计算模型模拟了纳米晶Ni的拉伸实验过程，对纳米晶Ni宏观力学行为和晶间微裂纹萌生与扩展之间的关系进行了研究，验证了针对超细晶和纳米晶力学性能的计算模型的有效性；同时，模拟结果表明，非均匀塑性变形导致高应变梯度效应，晶粒塑性变形强化显著，使晶界主导的变形机制对纳米晶金属的整体力学性能产生重要影响．
英文摘要：
The intergranular fracture characteristics in nanocrystalline and ultra-fine polycrys- talline metallic materials present intensive size effect and microstructure geometry effect. The conventional elastic-plastic constitutive theory is unable to describe these effects because it doesn＇t contain any length parameters to characterize the scale changing. Regarding this, a micro-structured model was proposed for the study on intergranular fracture of nanocrystalline and microcrystalline metals （mainly for the fcc metals）. The hardening and size effects of material plastic deformation are described by the computational model based on the conventional theory of mechanism-based strain gradient plasticity （CMSG）. A cohesive interface model was used to simulate the processes of grain-boundary sliding and separation, the initiation and propagation of intergranular cracks until the material fracture. The tensile experiment and stress-strain curves of nanocrystalline Ni were simulated by using the present model. Then the relation between macroscopic mechanical behaviors and intergranular crack＇s initiation and propagation in nanocrystalline Ni was investigated. Through the simulation to the experimental result in literature, the validity of the proposed model calculated nanocrystalline and ultra-fine polycrystalline mechanical properties was confirmed. At the same time, the simulation results show that the high strain gradient effects and severely plastic hardening of grain are induced by inhomogeneous plastic deformation, and the grain boundary induced deformation has a significant influence on the overall mechanical properties of nanocrystalline metals.
同期刊论文项目
同项目期刊论文
Molecular dynamics study of mechanical behaviour of screw dislocation during cutting with diamond ti
Eigenfrequency Computation of Beam/Plate Carrying Concentrated Mass/Spring and Its Application to Re
Orientation-dependent adhesion strength of a rigid cylinder in non-slipping contact with a transvers
Response to "Comment on 'Deformation mechanisms of face-centeredcubic metal nanowires with twin boun
A simple method to simulate shrinkage-induced cracking in cement-based composites by lattice-type mo
Role of vertical component of surface tension of the droplet on the elastic deformation of PDMS memb
Shape effects on the yield stress and deformation of silicon nanowires: A molecular dynamics simulat
Adsorption of formaldehyde molecule on the intrinsic and Al-doped graphene: A first principle study.
Universal Biot number determining the stress duration and the susceptibility of ceramic cylinders to
An Elasto-plastic Damage Constitutive Theory Based on Pair Functional Potentials and Slip Mechanism,
Trans-scale mechanics – looking for the missing links between continuum and micro/nanoscopic reality
Universal Biot number determining stress duration and susceptibility of ceramic cylinders to quenchi
Determination of plastic properties by instrumented spherical indentation:Expanding cavity model and
A comparative study of Young’s modulus of single-walled carbon nanotube by CPMD, MD, and first princ
Analytical method of predicating the instabilities of a micro arch-shaped beam under electrostatic l
Failure process analysis of cement under explosive loading with a generalized driven nonlinear thres
Evaluation of effectiveness of representative methods for determining Young’s modulus and hardness f
Carbon nanotube reinforced hydroxyapatite composite coatings produced through laser surface alloying
Size, geometry and nonuniformity effects of surface-nanocrystalline aluminum in nanoindentation test
Response to Comment on Deformation mechanisms of face-centeredcubic metal nanowires with twin bounda
Determination of interface properties between micron-thick metal film and ceramic substrate using pe
Grain boundary effects on plastic deformation and fracture mechanisms in Cu nanowires: Molecular dyn
Formation of fivefold deformation twins in nanocrystalline face-centered-cubic copper based on molec
Trans-scale mechanics: looking for the missing links between continuum and micro/nanoscopic reality.
Atomistic investigation of the effects of temperature and surface roughness on diffusion bonding bet
Revelation of a functional dependence of the sum of two uniaxial strengths/hardness on elastic work/
Experimental verification and theoretical analysis of the relationships between hardness, elastic mo
The Influence of Annealing on Mechanical Properties of Hydrogenated Nanocrystalline Silicon Thin Fil
Nonlocality effect in atomic force microscopy measurement and its reduction by an approaching method
Inverse analysis to determine interfacial properties between metal film and ceramic substrate with a
Toughness of Ni/Al2O3 interfaces as dependent on micron-scale plasticity and atomistic-scale separat
Molecular/Cluster Statistical Thermodynamics (MST/CST) Simulation and Its Application to Nano-Indent
Peeling experiments of ductile thin films along ceramic substrates - - -Critical assessment of analy
期刊信息
位置：