The continuous extrusion forming process for producing large section copper concave bus bar under different extrusion wheel angular velocities was studied by three-dimensional finite element technology based on softwa...The continuous extrusion forming process for producing large section copper concave bus bar under different extrusion wheel angular velocities was studied by three-dimensional finite element technology based on software DEFORM-3D. The rigid-viscoplastic constitutive equation was employed in the model. The numerical simulation results show that the deformation body flow velocity in the die orifice increases gradually with the increase of the extrusion wheel angular velocity. But slippage between the rod and extrusion wheel occurs when the extrusion wheel angular velocity is high. The effective stress near the die orifice enhances gradually with increasing extrusion wheel angular velocity. High stress is concentrated in adjacent regions of the flash gap. The effective strain gradient is greater near the abutment than that near the die orifice. The effective strain of the product increases gradually with increasing extrusion wheel angular velocity. In the deformation process, the deformation body temperature increases remarkably due to friction and deformation. So the cooling is necessary in the region of the die and tools.展开更多
To investigate the metal flow during the railway wheel forming process, experiments and finite element method （FEM） simulation were carried out. An axisymmetric modeling for the wheel rolling process was proposed to...To investigate the metal flow during the railway wheel forming process, experiments and finite element method （FEM） simulation were carried out. An axisymmetric modeling for the wheel rolling process was proposed to predict the metal flow in radial direction, by which the whole multi-stage forming process could be simulated in axisymmetric and integral way. The result shows that the axisymmetric simulation method was an effective method to explore the metal flow in radial direction and to analyze the relationships of tools motion during the wheel rolling. The detail information about metal flow in railway wheel forming process was obtained. The metal in the wheel web was from the area near the half radius of the original billet; the chill zone of the billet became an envelope of the rim and part of the web with a maximum thickness of about 6 mm below the tread. At the wheel rolling stage, the metal in the rim flowed towards the web; the metal near the surfaces of the conjunction region between the web and rim suffered severe shear deformation.展开更多
文摘The continuous extrusion forming process for producing large section copper concave bus bar under different extrusion wheel angular velocities was studied by three-dimensional finite element technology based on software DEFORM-3D. The rigid-viscoplastic constitutive equation was employed in the model. The numerical simulation results show that the deformation body flow velocity in the die orifice increases gradually with the increase of the extrusion wheel angular velocity. But slippage between the rod and extrusion wheel occurs when the extrusion wheel angular velocity is high. The effective stress near the die orifice enhances gradually with increasing extrusion wheel angular velocity. High stress is concentrated in adjacent regions of the flash gap. The effective strain gradient is greater near the abutment than that near the die orifice. The effective strain of the product increases gradually with increasing extrusion wheel angular velocity. In the deformation process, the deformation body temperature increases remarkably due to friction and deformation. So the cooling is necessary in the region of the die and tools.
基金Sponsored by National High-tech Research and Development Program(863 Program)of China(2008AA030703)
文摘To investigate the metal flow during the railway wheel forming process, experiments and finite element method （FEM） simulation were carried out. An axisymmetric modeling for the wheel rolling process was proposed to predict the metal flow in radial direction, by which the whole multi-stage forming process could be simulated in axisymmetric and integral way. The result shows that the axisymmetric simulation method was an effective method to explore the metal flow in radial direction and to analyze the relationships of tools motion during the wheel rolling. The detail information about metal flow in railway wheel forming process was obtained. The metal in the wheel web was from the area near the half radius of the original billet; the chill zone of the billet became an envelope of the rim and part of the web with a maximum thickness of about 6 mm below the tread. At the wheel rolling stage, the metal in the rim flowed towards the web; the metal near the surfaces of the conjunction region between the web and rim suffered severe shear deformation.
