2006 Fiscal Year Final Research Report Summary
An investigation of the forming mechanisms of curved bars and twisted bars by extrusion through a die aperture with asymmetric cross section
| Project/Area Number |
17560110
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Production engineering/Processing studies
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| Research Institution | Takamatsu National College of Technology |
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Principal Investigator |
KIHARA Shigefumi Takamatsu National College of Technology, Mechanical Department, Professor, 機械工学科, 教授 (40332069)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRAISHI Mitsunobu University of FUICUI, Department of Mechanical Engineeling, Professor, 大学院工学研究科機械工学専攻, 教授 (30144885)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Extrusion / Simulation / Finite Element Analysis / Deformation Mechanism / Curved rectangular Bar / Curved rectangular Pipe |
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| Research Abstract |
The mechanisms responsible for the forming of rectangular bars and trapezoidal bars by extrusion at a fixed angle through a die aperture were investigated using numerical simulations. The greater the die inclination angle or the greater the aperture exit angle, the smaller the radius of curvature of the exiting bar. The calculated radius of curvature agreed well with the radius observed in experiments. The particle flow pattern, one of the outputs of the simulation, was used as a basis to investigate the mechanisms of curvature generation. When the die inclination angle was increased in the case of extrusion of rectangular bars, the volume of dead metal increased, causing material flow in the plane perpendicular to the extrusion direction. This gave rise to curvature in the extruded bar. It was also found that when the cross section was trapezoidal, the asymmetry of the container aperture caused differences in material flow velocity between the top and bottom portions; those differences affected curvature.
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