<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of the present study was to investigate the texture in dissimilar medium carbon steels welded by rotary ...<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of the present study was to investigate the texture in dissimilar medium carbon steels welded by rotary friction technique. The Electron Backscatter Diffraction (EBSD) technique was the main technique used to investigate the effect of welding on grain size and grain crystallographic orientation in the welded joint. Moreover, the effect of isothermal heat treatment at 600<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°C on welded joint has been studied knowing that this annealing allows to decrease the residual stresses. EBSD results revealed different subzones in welded joint. The texture in the weld is essentially composed of three components: Goss {110} <001>, Rotated Cube {100} <110>, and Rotated Goss {110} <110> orientation. The heat treatments applied on welded material had a slight effect on texture and grain size.展开更多
The interaction of water waves and seabed is studied by using Yamamoto's model, which takes into account the deformation of soil skeletal frame, compressibility of pore fluid flow as well as the Coulumb friction. ...The interaction of water waves and seabed is studied by using Yamamoto's model, which takes into account the deformation of soil skeletal frame, compressibility of pore fluid flow as well as the Coulumb friction. When analyzing the propagation of three kinds of stress waves in seabed, a simplified dispersion relation and a specific damping formula are derived. The problem of seabed stability is further treated analytically based on the Mohr-Coulomb theory. The theory is finally applied to the coastal problems in the Lian-Yun Harbour and compared with observations and measurements in soil-wave tank with satisfactory results.展开更多
The aim of this paper is two-dimensional magnetohydrodynamic viscous fluid bounded by infinite sheets to examine the Dufour and Soret effects on the （MHD） steady flow of an electrically conducting An incompressible...The aim of this paper is two-dimensional magnetohydrodynamic viscous fluid bounded by infinite sheets to examine the Dufour and Soret effects on the （MHD） steady flow of an electrically conducting An incompressible viscous fluid fills the porous space. The mathematical analysis is performed in the presence of viscous dissipation, Joule heating, and a first-order chemical reaction. With suitable transformations, the governing partial differential equations through momentum, energy, and concentration laws are transformed into ordinary differential equations. The resulting equations are solved by the homotopy analysis method （HAM）. The convergence of the series solutions is ensured. The effects of the emerging parameters, the skin friction coefficient, the Nusselt number, and the Sherwood number are analyzed on the dimensionless velocities, temperature, and concentration fields.展开更多
The 3-D traction field in the pressure screw-pair of a 3 500 heavy and mediumplate mill press down system is successfully calculated by applying the 3-D frictional contactmultipole-BEM and the corresponding program th...The 3-D traction field in the pressure screw-pair of a 3 500 heavy and mediumplate mill press down system is successfully calculated by applying the 3-D frictional contactmultipole-BEM and the corresponding program that has been developed. The computing results show themedium diameter orientation is unreliable, especially under the interference of an outer forcecouple. Under such working conditions, the circumferential traction distribution on the screw teethis extremely uneven, which is the main reason for the destruction and short life time ofscrew-pairs. When utilizing the same precision (the relative tolerance is 10X10^(-5)), themultipole-BEM uses almost the same CPU time as used by the FEM, but the needed computer memory sizeis only one eightieth of that needed by the FEM (10 MB vs. 800 MB). The multipole-BEM is well suitedfor computing large-scale engineering problems.展开更多
The laminar fully developed free-convection flow in a channel bounded by two vertical plates, partially filled with porous matrix and partially with a clear fluid, has been discussed when both the plates are moving in...The laminar fully developed free-convection flow in a channel bounded by two vertical plates, partially filled with porous matrix and partially with a clear fluid, has been discussed when both the plates are moving in opposite direction. Two regions are coupled, by equating the velocity and shear stress at the interface. The momentum transfer in porous medium has been described by the Brinkman-extended Darcy model. The affect of Darcy number on flow velocity has been discussed in fluid region, interface region and porous medium with the help of graphs. Analytic method has been adopted to obtain the expressions of velocity and temperature. The skin-friction component has also been determined and presented with the help of tables.展开更多
The movement of lubricated fibres in a fibre assembly is investigated theoretically and aviscous sliding model of friction is proposed.Previous work and experimental results are discussedin relation to the model.Resul...The movement of lubricated fibres in a fibre assembly is investigated theoretically and aviscous sliding model of friction is proposed.Previous work and experimental results are discussedin relation to the model.Results of drawing experiments carried out on wool slivers are also pres-ented and discussed.展开更多
文摘<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of the present study was to investigate the texture in dissimilar medium carbon steels welded by rotary friction technique. The Electron Backscatter Diffraction (EBSD) technique was the main technique used to investigate the effect of welding on grain size and grain crystallographic orientation in the welded joint. Moreover, the effect of isothermal heat treatment at 600<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°C on welded joint has been studied knowing that this annealing allows to decrease the residual stresses. EBSD results revealed different subzones in welded joint. The texture in the weld is essentially composed of three components: Goss {110} <001>, Rotated Cube {100} <110>, and Rotated Goss {110} <110> orientation. The heat treatments applied on welded material had a slight effect on texture and grain size.
基金The project supported by the National Natural Science Foundation of China
文摘The interaction of water waves and seabed is studied by using Yamamoto's model, which takes into account the deformation of soil skeletal frame, compressibility of pore fluid flow as well as the Coulumb friction. When analyzing the propagation of three kinds of stress waves in seabed, a simplified dispersion relation and a specific damping formula are derived. The problem of seabed stability is further treated analytically based on the Mohr-Coulomb theory. The theory is finally applied to the coastal problems in the Lian-Yun Harbour and compared with observations and measurements in soil-wave tank with satisfactory results.
基金Project supported by the Deanship of Scientific Research (DSR) of King Abdulaziz University of Saudi Arabia (No. HiCi/40-3/1432H)
文摘The aim of this paper is two-dimensional magnetohydrodynamic viscous fluid bounded by infinite sheets to examine the Dufour and Soret effects on the （MHD） steady flow of an electrically conducting An incompressible viscous fluid fills the porous space. The mathematical analysis is performed in the presence of viscous dissipation, Joule heating, and a first-order chemical reaction. With suitable transformations, the governing partial differential equations through momentum, energy, and concentration laws are transformed into ordinary differential equations. The resulting equations are solved by the homotopy analysis method （HAM）. The convergence of the series solutions is ensured. The effects of the emerging parameters, the skin friction coefficient, the Nusselt number, and the Sherwood number are analyzed on the dimensionless velocities, temperature, and concentration fields.
基金This project is supported by National Natural Science Foundation of China(No.50075075) National "Ten-Five" Science and Technology Project of China(No.ZZ 01-13A-02-02-03). J
文摘The 3-D traction field in the pressure screw-pair of a 3 500 heavy and mediumplate mill press down system is successfully calculated by applying the 3-D frictional contactmultipole-BEM and the corresponding program that has been developed. The computing results show themedium diameter orientation is unreliable, especially under the interference of an outer forcecouple. Under such working conditions, the circumferential traction distribution on the screw teethis extremely uneven, which is the main reason for the destruction and short life time ofscrew-pairs. When utilizing the same precision (the relative tolerance is 10X10^(-5)), themultipole-BEM uses almost the same CPU time as used by the FEM, but the needed computer memory sizeis only one eightieth of that needed by the FEM (10 MB vs. 800 MB). The multipole-BEM is well suitedfor computing large-scale engineering problems.
文摘The laminar fully developed free-convection flow in a channel bounded by two vertical plates, partially filled with porous matrix and partially with a clear fluid, has been discussed when both the plates are moving in opposite direction. Two regions are coupled, by equating the velocity and shear stress at the interface. The momentum transfer in porous medium has been described by the Brinkman-extended Darcy model. The affect of Darcy number on flow velocity has been discussed in fluid region, interface region and porous medium with the help of graphs. Analytic method has been adopted to obtain the expressions of velocity and temperature. The skin-friction component has also been determined and presented with the help of tables.
文摘The movement of lubricated fibres in a fibre assembly is investigated theoretically and aviscous sliding model of friction is proposed.Previous work and experimental results are discussedin relation to the model.Results of drawing experiments carried out on wool slivers are also pres-ented and discussed.
