Upper Bound Analysis of Tube Extrusion Process Through Rotating Conical Dies with Large Mandrel Radius
الموضوعات :
1 - Mechanical Engineering Department, Razi University, Kermanshah
2 - Mechanical Engineering Department, Razi University, Kermanshah
الکلمات المفتاحية: Tube extrusion, Rotating conical die, Upper bound method,
ملخص المقالة :
In this paper, an upper bound approach is used to analyze the tube extrusion process through rotating conical dies with large mandrel radius. The material under deformation in the die and inside the container is divided to four deformation zones. A velocity field for each deformation zone is developed to evaluate the internal powers and the powers dissipated on all frictional and velocity discontinuity surfaces. By minimization of the total power with respect to the slippage parameter between tube and the die and equating it with the required external power, the extrusion pressure is determined. The corresponding results for rotating conical dies are also determined by using the finite element code, ABAQUS. The analytical results show a good coincidence with the results by the finite element method with a slight overestimation. Finally, the effects of various process parameters such as mandrel radius, friction factor, etc., upon the relative extrusion pressure are studied.
[1] Ma X., Barnett M., 2005, An upper bound analysis of forward extrusion through rotating dies, In Proceedings of the 8th ESAFORM Conference on Material Forming, Bucharest, Romania.
[2] Bochniak W., Korbel A., 1999, Extrusion of CuZn39Pb2 alloy by the KOBO method, Engineering Transactions 47: 351-367.
[3] Bochniak W., Korbel A., 2000, Plastic flow of aluminum extruded, under complex conditions, Matererials Science and Technology 16: 664-674.
[4] Bochniak W., Korbel A., 2003, KOBO-type forming: forging of metals under complex conditions of the process, Journal of Materials Processing Technology 134: 120-134.
[5] Kim Y.H., Park J.H., 2003, Upper bound analysis of torsional backward extrusion process, Journal of Materials Processing Technology 143-144: 735-740.
[6] Ma X., Barnett M., Kim Y. H., 2004, Forward extrusion through steadily rotating conical dies, Part I: experiments, International Journal of Mechanical Sciences 46: 449- 464.
[7] Ma X., Barnett M., Kim Y. H., 2004, Forward extrusion through steadily rotating conical dies, Part II: theoretical analysis, International Journal of Mechanical Sciences 46: 465-489.
[8] Maciejewski J., Mroz Z., 2008, An upper-bound analysis of axisymmetric extrusion assisted by cyclic torsion, Journal of Materials Processing Technology 206: 333-344.
