| Project/Area Number |
17560088
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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 | Iwate University |
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Principal Investigator |
KASABA Koichi Iwate University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (00271841)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Press working / Forming / Die / Strain / Monitoring |
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| Research Abstract |
Deep drawing tests were conducted by the die with sphere or cylinder head punch installed in hydraulically-operated loading test machine. The drawing test with excessive blank holding force (BHF) causing a fracture of a blank, with insufficient BHF causing a wrinkle of a blank and with too large drawing ratio causing a fracture of a blank were conducted.. The strain of the punch was measured and was tried to be correlated to a static macroscopic and a dynamic microscopic behaviors of a blank.
The drawing process was categorized into 6 modes by the change of a gradient or the point of inflection of load versus drawing-height curve. These categorized modes could be correlated to each macroscopic mechanical behavior of a blank, contact to a die, onset of plastic deformation, crack propagation, wrinkle and so on.
On the other hand, a small strain fluctuation of the punch is caused by an abrupt drop of a load and recover of it. It could be correlated to each microscopic mechanical behavior, lubricant state between a die and a blank, a microscopic crack initiation and so on. Especially frequent fluctuate strain could be correlated to slip-stick behavior between a shoulder of a die and a blank. The amount of an abrupt drop of a load in this material corresponded to about 3 % to total load needed for deep drawing.
Therefore deep drawing process can be evaluated on site by monitoring strain behavior of the punch.
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