| Project/Area Number |
63850108
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
コンクリート工学・土木材料・施工
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| Research Institution | Saitama University |
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Principal Investigator |
MACHIDA Atsuhiko Saitama University Department of Construction Engineering, Professor, 工学部, 教授 (50008869)
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| Co-Investigator(Kenkyū-buntansha) |
MUTSUYOSHI Hiroshi Saitama University Department of Construction Engineering, Associate Professor, 工学部, 助教授 (60134334)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 1989: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1988: ¥3,500,000 (Direct Cost: ¥3,500,000)
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| Keywords | pseudodynamic test / step-by-step loading / strain rate effect / single degree of freedom system / reinforced concrete structures / evaluation of seismic resistance / 擬似動的実験 / 振動実験 / アンダーシュート誤差 |
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| Research Abstract |
1. Errors due to undershoot, which has been considered to be one of the problematic points in pseudodynamic test, can be made negligibly small if allowable difference between target displacements and attained ones is made as small as possible and the increments of displacement to attain a target displacement are decreased in a geometric ratio.
2. In pseudodynamic test, the restoring force at each loading step is underestimated due to load drop which occurs during the calculation process for the target displacement of next step, and if such underestimation occurs at a step, the test is carried out based on incorrect data afterwards. To overcome this, it is necessary to modify the measured restoring forces. Though the amount of the modification is not very large, the modification is needed at almost all loading steps.
3. In pseudodynamic test, restoring forces are also underestimated sometimes owing to its static loading process, in which strain rate effect is neglected. Since the amount of underestimation is considerably high though it rarely occurs, the underestimated restoring forces should be modified to obtain correct results.
4. We developed a pseudodynamic testing system, taking all of the results described above into consideration. The developed system can simulate satisfactorily accurately responses to earthquakes of reinforced concrete structures of single degree of freedom. It gives one of possible responses to such a severe loading that peak response displacements increase continuously and force the load carrying capacity to enter its descending range.
5. The future issues of the developed system are to evaluate universally the needed modifications and to enlarge the applicable range to multi degree of freedom system.
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