作者机构：
[Yu, M.] Cent South Univ Forestry & Technol, Hunan Prov Key Lab Engn Rheol, Changsha 410004, Hunan, Peoples R China.;[Peng, X. H.] Cent South Univ Forestry & Technol, Swan Coll, Changsha 410004, Hunan, Peoples R China.;[Wen, P. H.] Queen Mary Univ London, Sch Engn & Mat Sci, London E1 4NS, England.
通讯机构：
[Peng, X. H.] C;Cent South Univ Forestry & Technol, Swan Coll, Changsha 410004, Hunan, Peoples R China.
摘要：
The theoretical model of an edge dislocation near interface collinear crack tips in nanocrystalline bi-materials with cooperative grain boundary sliding and migration is formulated. As a typical example, we focus on analyzing the effect of two disclination dipoles produced by cooperative grain boundary sliding and migration on an edge dislocation emitting from a finite interfacial crack tip in nanocrystalline bi-materials. The dislocation force and the critical stress intensity factors for an edge dislocation emitting from an interface collinear crack tip under remote plane loadings are derived by using the complex potential method. And the influences of grain size, disclination strength, migration distance, sliding distance and interface crack length on the critical stress intensity factors are discussed in detail. It can be found that the effect of cooperative grain boundary sliding and migration deformation on the dislocation emission from interface collinear crack tip lies in the crack length, the dislocation emission angle, and the strength of the cooperative deformation itself.
期刊：
DEStech Transactions on Environment, Energy and Earth Sciences,2018年(ICPEEE):207-211 ISSN：2475-8833
作者机构：
[Min YU; Yu-xuan YANG; Xiang-hua PENG] Hunan Provincial Key Laboratory of Engineering Rheology,Central South University of Forestry and Technology;[Min YU; Yu-xuan YANG; Xiang-hua PENG] Swan College of Central South University of Forestry and Technology Hunan University
摘要：
The paper is aimed to investigate a theoretical model that a screw dipole inside an elastic elliptical inhomogeneity that containing a confocal line crack under longitudinal shear.The analytic solutio
摘要：
The work is devoted to investigate the interaction between the special rotational deformation and interface collinear cracks in nanocrystalline bi-materials. As an illustrative example, the effect of the disclination quadrupole produced by the special rotational deformation on the emission of lattice dislocation from a finite interfacial crack tip in nanocrystalline bi-material is explored theoretically using the complex variable method. The complex form expression of dislocation force and the critical stress intensity factors for the first edge dislocation emission under remote mode I loadings and mode II loadings are deduced. And the influences of material properties, grain size, disclination strength, disclination location and orientation, special rotational deformation orientations, and crack length on the critical stress intensity factors are discussed in detail. The results show that the special rotational deformation and the relative shear modulus of the upper the lower half plane have great effect on the lattice dislocation emission from the interface collinear crack tip.
摘要：
The interaction problem of a piezoelectric screw dislocation dipole with a confocal elliptic blunt crack in elliptical inhomogeneity subjected to remote anti-plane stress field and in-plane electric field is investigated by using the complex method of elasticity. The exact closed-form solutions of a series of quantities, such as singularity stress field, image force and image torque acting on the center of screw dislocation dipole, stress intensity factor and electric displacement intensity factor of crack tip, energy release rate, and generalized strain energy density are obtained. Then the influence laws of remote load, the dip angle of dislocation dipole, the size of blunt crack, and the material constants on the quantities are analyzed. The numerical results show that the image force, image torque, stress intensity factor, and electric displacement intensity factor make periodic variation as the dip angle of dislocation dipole; the energy release rate of crack tip is negative when subjected to pure electric field, however, it can be positive or negative when subjected to the combined action of mechanical field and electric field; the sharp crack is not easy to expand in some combined action of mechanical field and electric field.
摘要：
By using the complex variable method, the electro-elastic interaction between a piezoelectric screw dislocation in the infinite half-plane and a semi-elliptical interface crack under remote anti-plane shear stresses and in-plane electric loads in piezoelectric bi-material is investigated, and the general solutions to the problem are obtained. The complex potentials, the generalized stress fields, the generalized stress intensity factors and energy release rate of crack tip, and the image force acting on the dislocation are also calculated. The influences of the electro-elastic constants and the location of the screw dislocation upon the stress intensity factor and the image force are discussed, while the influence of remote loading upon the energy release rate is also analyzed. The results indicate that the crack and the lower half plane may attract or repel dislocation with parameters changes when dislocation lies on the upper half plane and the shape of the crack is fixed. The shielding effect is stronger when the piezoelectric coefficient of the upper half plane is larger than that of the lower half plane, and the influence of relative shear modulus upon the shielding effect is relatively smaller when the relative piezoelectric coefficients take fixed values. The energy release rate may be positive or negative under a combined electric load and mechanical load. Both increasing electric field and decreasing mechanical load can decrease the energy release rate thereby enhancing the restraint of the crack expansion.
作者机构：
中南林业科技大学土木工程与力学学院,湖南长沙410004;湖南大学机械与运载工程学院,湖南长沙410082;湖南大学机械与运载工程学院,湖南长沙,410082;[余敏] College of Civil Engineering and Mechanics, Central South University of Forestry and Technology, Changsha, Hunan 410004, China<&wdkj&>College of Mechanical and Vehicle Engineering, Hunan University, Changsha, Hunan 410082, China;[方棋洪; 刘又文] College of Mechanical and Vehicle Engineering, Hunan University, Changsha, Hunan 410082, China
通讯机构：
College of Civil Engineering and Mechanics, Central South University of Forestry and Technology, China
摘要：
The paper established a model to investigate the interaction between the special rotational deformation and a semielliptical blunt crack in deformed nanocrystalline materials. By using the complex variable method, the effect of a disclination quadrupole produced by the special rotational deformation on the emission of lattice dislocation from a semielliptical blunt crack tip was explored theoretically. The complex form expression of the dislocation force was derived, and the critical stress intensity factors (SIFs) for the first edge dislocation emission were calculated. Then, the influence of the disclination strength, the disclination location and orientation, the special rotational deformation orientation, the grain size, and the curvature radius of blunt crack tip on the critical SIFs were discussed in detail, and a comparison with the sharp crack behavior was presented. The results show that the special rotational deformation and the curvature radius of blunt crack have great effects on the lattice dislocation emission form blunt crack tip. Some influence laws are also different with those of the edge dislocation emission from a sharp crack tip.
摘要：
The control of subgrade settlement has been the main influencing factor on highroad pavement quality, so estimating settlement amount after construction based on designed embankment height and planning the construction filling height beforehand through the settlement prediction is a very important work. Because of the complex coupling properties and high nonlinear characteristics of the factors influencing foundation settlement, a soft-roadbed settlement prediction model based on RBFNN (Radial Basis Function Neural Network) is proposed, combining the global fitting properties of RBFNN. The analysis shows that the model owns good fitting property and high prediction precise, and certain practical value.
摘要：
The inelastic response constitutive description of metal material under different stress and wide temperature range is very important in many practical engineering. It can accurately reflect the level of material rate sensitivity and set up a simple and practical strengthening evolution rate. Take No.35 steel as an example; because of the action of load, temperature, time and other factors in its forming process, the creep relation is very important and complex. In view of this situation, the BC-BPNN (Based on Back propagation Neural Network), owing high precision nonlinear fitting ability has and good generalization ability, is applied to the research on creep constitutive relationship of 35 steel. At first, the creep relationship is numerically fitted using testing data of 35 steel; then, the fitting results is compared with the creep testing data. The results show that the applying of BC-BPNN to research on metal creep relationship has a strong practical value.
作者机构：
[Min Yu; Qihong Fang; Hui Fen; Youwen Liu] State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University;[Min Yu; Qihong Fang; Hui Fen; Youwen Liu] College of Civil Engineering and Mechanics,Central South University of Forestry and Technology,Changsha 410004,China
会议名称：
13th International Conference on Fracture（ICF13）
会议时间：
2013-06-16
会议地点：
中国北京
摘要：
<正>The paper established a grain size dependent theoretical model to investigate the combined effects of special rotational deformation and emission of edge dislocations from semi-elliptical blunt cra
期刊：
Applied Mechanics and Materials,2012年182-183:1549-1553 ISSN：1660-9336
通讯作者：
Liu, Y.(liuyouw8294@sina.com)
作者机构：
[Min Yu] Department of Civil Engineering and Mechanics, Central South University of Forestry and Technology, Changsha 410004, China;[Min Yu; You Wen Liu] State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China
通讯机构：
[Liu, Y.] S;State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, , Changsha 410082, China
会议名称：
2012 International Applied Mechanics, Mechatronics Automation Symposium, IAMMAS 2012
会议时间：
7 September 2012 through 9 September 2012
会议地点：
沈阳
会议论文集名称：
2012 International Applied Mechanics,Mechatronics Automation Symposium(2012应用力学,机电一体化自动化国际研讨会)(IAMMAS2012)论文集
作者机构：
[余敏] Institute of Rheological Mechanics and Material Engineering, Central South University of Forestry and Technology, Changsha, 410004, China;[余敏; 刘又文] College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
通讯机构：
[Liu, Y.] C;College of Mechanical and Vehicle Engineering, , Changsha, 410082, China
