| Project/Area Number |
10650472
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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 |
構造工学・地震工学
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| Research Institution | Daido Institute of Technology |
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Principal Investigator |
MIKI Toshihiro Daido Institute of Technology, Civil Engineering Dept.,Professor, 工学部, 教授 (90137175)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUSAWA Tomisaku Daido Institute of Technology, Civil Engineering Dept.,Professor, 工学部, 教授 (60113081)
KOTOGUCHI Hisao Daido Institute of Technology, Civil Engineering Dept.,Professor, 工学部, 教授 (60047305)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | portal frame / earthquake response / collapse mechanism / shear buckling / web plate of beam / partially tapered member / 鋼製橋脚 / 変断面 / ラーメン / 非弾性 / 腹板 / 履歴減衰 |
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| Research Abstract |
This research project studies the hysteresis damping behavior of steel frames with collapse of beam subjected to earthquake ground motion. Attention is paid to the collapse mechanism of portal frames with the collapse type of beam member
1) The cumulative plastic strain of the column base parts, panel zones and column cross-section near panel zones decreases due to the shear collapse of web plates in beam. It should be noted that the strain rate of such shear panels in the plastic range is so high compared with that of column cross-sections.
2) The numerical results demonstrate the fundamental plastic mechanism of frames with the shear collapse in the middle of beam and another collapse mechanism, which includes the shear yielding of panel zones in the beam-to-column connections. This mechanism is caused by the increase in shearing force due to strain hardening in the middle of beam.
3) The partially tapered beam-columns subjected to cyclic bending can delays the occurrence of local buckling. The resulting damage is less than the uniform cross-section members and corresponding dissipated energy becomes larger with the increase in type ratio.
4) The plastic bending deformation of the partially tapered sections set in beam near the beam-to-column connections can delay the increase in shearing force in beam. The resulting panel zones of connection remain almost elastic state.
5) The decrease in the shear strength of web plates in beam eliminates the hysteresis damping effect corresponding to dissipated energy. It should be noted that the damage of column base parts and sway response of frames might become significant.
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