Backward spinning is analyzed by 3D rigid-plastic FEM.A 3D mechanical model for backward spinning is presented. The distributions are obtained of strain一rate and stress in the con- tact area of the roller a...Backward spinning is analyzed by 3D rigid-plastic FEM.A 3D mechanical model for backward spinning is presented. The distributions are obtained of strain一rate and stress in the con- tact area of the roller and its adjacent area.The results can well intemret the principle of defonnation of backward spinning. The relationship between the roller angle and three components ofspinning force is found out, and the optimum roller angle, when the general spinning foree gets to the minimum value, is calculated. The distributions of defonnation area obtained by FEM agree with the experimental result well.展开更多
Springback is one of important factors influencing the forming quality of numerical control （NC） bending of thin-walled tube. In this paper, a numerical-analytic method for springback angle prediction of the process...Springback is one of important factors influencing the forming quality of numerical control （NC） bending of thin-walled tube. In this paper, a numerical-analytic method for springback angle prediction of the process was put forward. The method is based on springback angle model derived using analytic method and simulation results from three-dimensional （3D） rigid-plastic finite element method （FEM）. The method is validated through comparison with experimental results. The features of the method are as follows： （1） The method is high in efficiency because it combines advantages of rigid-plastic FEM and analytic method. （2） The method is satisfactory in accuracy, since the field variables used in the model is resulting from 3D rigid-plastic FEM solution, and the effects both of axial force and strain neutral axis shift have been included. （3） Research on multi-factor effects can be carried out using the method due to its advantage inheriting from rigid-plastic FEM. The method described here is also of general significance to other bending processes.展开更多
文摘Backward spinning is analyzed by 3D rigid-plastic FEM.A 3D mechanical model for backward spinning is presented. The distributions are obtained of strain一rate and stress in the con- tact area of the roller and its adjacent area.The results can well intemret the principle of defonnation of backward spinning. The relationship between the roller angle and three components ofspinning force is found out, and the optimum roller angle, when the general spinning foree gets to the minimum value, is calculated. The distributions of defonnation area obtained by FEM agree with the experimental result well.
基金This work was supported by the National Natural Science Foundation of China for Distinguished Young Scholars （Grant No. 50225518）the Teaching and Research Award Program for 0utstanding Young Teachers in Higher Education Institution of M0E, PRCthe Aeronautical Science Foundation of China （Grant No. 04H53057）.
文摘Springback is one of important factors influencing the forming quality of numerical control （NC） bending of thin-walled tube. In this paper, a numerical-analytic method for springback angle prediction of the process was put forward. The method is based on springback angle model derived using analytic method and simulation results from three-dimensional （3D） rigid-plastic finite element method （FEM）. The method is validated through comparison with experimental results. The features of the method are as follows： （1） The method is high in efficiency because it combines advantages of rigid-plastic FEM and analytic method. （2） The method is satisfactory in accuracy, since the field variables used in the model is resulting from 3D rigid-plastic FEM solution, and the effects both of axial force and strain neutral axis shift have been included. （3） Research on multi-factor effects can be carried out using the method due to its advantage inheriting from rigid-plastic FEM. The method described here is also of general significance to other bending processes.
