Flexible spinning is a new type of spinning process where spin-forming isperformed without using a mandrel. Combining shearing and rolling processes, the calculationformulas of the spinning forces in flexible spinning...Flexible spinning is a new type of spinning process where spin-forming isperformed without using a mandrel. Combining shearing and rolling processes, the calculationformulas of the spinning forces in flexible spinning of cones is presented. The effects of the mainprocessing parameters, such as gripping force G applied to the blank by the inner roller, the feedrate of rollers f and the roundness radius of outer roller r_o, on the spinning forces are analyzedexperimentally and theoretically.展开更多
This article presents illustrations of an extended model of the electron to visualize how it spins and radiates in the external magnetic field. A time-varying magnetic field B produces a rotational induced electric fi...This article presents illustrations of an extended model of the electron to visualize how it spins and radiates in the external magnetic field. A time-varying magnetic field B produces a rotational induced electric field E which rotates (spins) the electron about its axis. In time-constant magnetic field: the electron radiates the cyclotron radiation. In time-varying magnetic field: synchrotron radiation is generated. The couplings between spin, acceleration and radiation will be discussed.展开更多
Ball spinning is applied to manufacturing thin-walled tube with high precision and high mechanical properties. On the basis of plastic mechanics, by simplifying ball spinning of thin-walled tube as plane strain proble...Ball spinning is applied to manufacturing thin-walled tube with high precision and high mechanical properties. On the basis of plastic mechanics, by simplifying ball spinning of thin-walled tube as plane strain problem, slab method is used for the purpose of calculating the contact deformation pressure. The spinning force components, the torsional moment, the deformation power and the deformation work are calculated further as well. The influence of the two important process parameters such as the feed ratio and the ball diameter on the spinning force components is analyzed in order to further control the spinning force components by regulating the two process variables during the ball spinning process. The stress and strain state in deformable zone as well as mechanics boundary conditions in ball spinning are obtained. The effect of the three spinning force components on the formability of the spun part is analyzed and validated through the ball spinning experiments. The theoretical and experimental results show that the radial spinning component plays a significant role in ball spinning of thin-walled tube, and the mechanics situation in backward ball spinning contributes to enhancing the plasticity of the metal material, but that in forward ball spinning contributes to advancing the axial flow of the metal material.展开更多
As a successive and local plastic deformation process, backward ball spinning was applied for the purpose of prodacing thin-walled tubular parts with longitudinal inner ribs. According to the local plastic deformation...As a successive and local plastic deformation process, backward ball spinning was applied for the purpose of prodacing thin-walled tubular parts with longitudinal inner ribs. According to the local plastic deformation theoo,, the application of yield criterion to the spinning process and the influence of the radial spinning force component on the formability of inner ribs were analyzed. Based on yield criterion and plastic mechanics, the stable flow rule of metal material and forming criteria of the inner ribs were obtained aad conformed to the experimental results so as to contribute greatly to improving the ball spinning process and optimizing the process variables, such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank, which have a significant influenee on the formability of the inner ribs. The knowledge of the influence of the process variables such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank on the spinning process is essential to preventing the quality defects of the spun parts and obtaining the desired spun parts.展开更多
In this article the electron is conceived as an extended particle, consisting of a negatively charged core (-q<sub>0</sub>) which is surrounded by a cloud of electric dipoles (-q, +q). The article presents...In this article the electron is conceived as an extended particle, consisting of a negatively charged core (-q<sub>0</sub>) which is surrounded by a cloud of electric dipoles (-q, +q). The article presents the illustrations that show how and why the electron spins and radiates in an external electric field. In the appendices, Bremsstrahlung & Cerenkov radiations, and the processes of Emission & Absorption of photons will be discussed.展开更多
The cyclic symmetry and local fine-mesh technology were adopted in the establishment of numerical simulation model for inner gear spin-forming. And the processing experiment was proceeded to verify the reliability of ...The cyclic symmetry and local fine-mesh technology were adopted in the establishment of numerical simulation model for inner gear spin-forming. And the processing experiment was proceeded to verify the reliability of the established model. The simulation result indicates that besides radial and axial flows, there also exists rather large tangential flow, which results in an increase of forming force in tangential direction. Furthermore, the un-uniform deformation of metal during spin-forming would cause forming defects, such as underfill in tooth fillet region and indentation on the outside spun part.展开更多
Based on the covariant Lagrangian function and Euler-Lagrange equation,a set of classical fluid equations for strong EM wave-spin plasma interaction is derived.Analysis shows that the relativistic effects may affect t...Based on the covariant Lagrangian function and Euler-Lagrange equation,a set of classical fluid equations for strong EM wave-spin plasma interaction is derived.Analysis shows that the relativistic effects may affect the interaction processes by three factors:the relativistic factor,the time component of four-spin,and the velocity-field coupling.This set of equations can be used to discuss the collective spin effects of relativistic electrons in classical regime,such as astrophysics,high-energy laser-plasma systems and so on.As an example,the spin induced ponderomotive force in the interaction of strong EM wave and magnetized plasma is investigated.Results show that the time component of four-spin,which approaches to zero in nonrelativistic situations,can increase the spin-ponderomotive force obviously in relativistic situation.展开更多
文摘Flexible spinning is a new type of spinning process where spin-forming isperformed without using a mandrel. Combining shearing and rolling processes, the calculationformulas of the spinning forces in flexible spinning of cones is presented. The effects of the mainprocessing parameters, such as gripping force G applied to the blank by the inner roller, the feedrate of rollers f and the roundness radius of outer roller r_o, on the spinning forces are analyzedexperimentally and theoretically.
文摘This article presents illustrations of an extended model of the electron to visualize how it spins and radiates in the external magnetic field. A time-varying magnetic field B produces a rotational induced electric field E which rotates (spins) the electron about its axis. In time-constant magnetic field: the electron radiates the cyclotron radiation. In time-varying magnetic field: synchrotron radiation is generated. The couplings between spin, acceleration and radiation will be discussed.
基金supported by Overseas Returnee Foundation of Heilongjiang Province, China (lc01c13).
文摘Ball spinning is applied to manufacturing thin-walled tube with high precision and high mechanical properties. On the basis of plastic mechanics, by simplifying ball spinning of thin-walled tube as plane strain problem, slab method is used for the purpose of calculating the contact deformation pressure. The spinning force components, the torsional moment, the deformation power and the deformation work are calculated further as well. The influence of the two important process parameters such as the feed ratio and the ball diameter on the spinning force components is analyzed in order to further control the spinning force components by regulating the two process variables during the ball spinning process. The stress and strain state in deformable zone as well as mechanics boundary conditions in ball spinning are obtained. The effect of the three spinning force components on the formability of the spun part is analyzed and validated through the ball spinning experiments. The theoretical and experimental results show that the radial spinning component plays a significant role in ball spinning of thin-walled tube, and the mechanics situation in backward ball spinning contributes to enhancing the plasticity of the metal material, but that in forward ball spinning contributes to advancing the axial flow of the metal material.
基金Funded by the Overseas Returnee Foundation of HeilongjiangProvince (lc01c13)
文摘As a successive and local plastic deformation process, backward ball spinning was applied for the purpose of prodacing thin-walled tubular parts with longitudinal inner ribs. According to the local plastic deformation theoo,, the application of yield criterion to the spinning process and the influence of the radial spinning force component on the formability of inner ribs were analyzed. Based on yield criterion and plastic mechanics, the stable flow rule of metal material and forming criteria of the inner ribs were obtained aad conformed to the experimental results so as to contribute greatly to improving the ball spinning process and optimizing the process variables, such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank, which have a significant influenee on the formability of the inner ribs. The knowledge of the influence of the process variables such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank on the spinning process is essential to preventing the quality defects of the spun parts and obtaining the desired spun parts.
文摘In this article the electron is conceived as an extended particle, consisting of a negatively charged core (-q<sub>0</sub>) which is surrounded by a cloud of electric dipoles (-q, +q). The article presents the illustrations that show how and why the electron spins and radiates in an external electric field. In the appendices, Bremsstrahlung & Cerenkov radiations, and the processes of Emission & Absorption of photons will be discussed.
基金Support by National Natural Science Foundation of China (50475097)Provincial Natural Science Foundation of Guangdong (04105943)Industrial Science and Technology Development Program Foundation of Guangdong (600611901001)
文摘The cyclic symmetry and local fine-mesh technology were adopted in the establishment of numerical simulation model for inner gear spin-forming. And the processing experiment was proceeded to verify the reliability of the established model. The simulation result indicates that besides radial and axial flows, there also exists rather large tangential flow, which results in an increase of forming force in tangential direction. Furthermore, the un-uniform deformation of metal during spin-forming would cause forming defects, such as underfill in tooth fillet region and indentation on the outside spun part.
基金supported by National Natural Science Foundation of China(No.12065011)Science and Technology Research Project of Jiangxi Provincial Department of Education(No.GJJ170642)。
文摘Based on the covariant Lagrangian function and Euler-Lagrange equation,a set of classical fluid equations for strong EM wave-spin plasma interaction is derived.Analysis shows that the relativistic effects may affect the interaction processes by three factors:the relativistic factor,the time component of four-spin,and the velocity-field coupling.This set of equations can be used to discuss the collective spin effects of relativistic electrons in classical regime,such as astrophysics,high-energy laser-plasma systems and so on.As an example,the spin induced ponderomotive force in the interaction of strong EM wave and magnetized plasma is investigated.Results show that the time component of four-spin,which approaches to zero in nonrelativistic situations,can increase the spin-ponderomotive force obviously in relativistic situation.