2007 Fiscal Year Final Research Report Summary
DYNAMIC CHARACTERISTICS OF REINFORCED CONCRETE MEMBERS UNDER COMBINED STRESS CONDITION SUBJECTED TO CYCLIC AXIAL FORCE, TWO-AXIS BENDING, AND TORSION
| Project/Area Number |
17360215
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | Kyushu University |
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Principal Investigator |
OTSUKA Hisanori Kyushu University, DEPARTMENT OF CIVIL AND STRUCTURAL ENGINEERING, PROFESSOR (70108653)
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| Co-Investigator(Kenkyū-buntansha) |
KAJITA Yukihide KYUSHU UNIVERSITY, DEPARTMENT OF CIVIL AND STRUCTURAL ENGINEERING, ASSOCIATE PROFESSOR (10403940)
FURUKAWA Aiko KYUSHU UNIVERSITY, DEPARTMENT OF CIVIL AND STRUCTURAL ENGINEERING, ASSISTANT PROFESSOR (00380585)
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| Project Period (FY) |
2005 – 2007
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| Keywords | REINFORCED CONCRETE MEMBERS / CYCLIC LOADING OF AXIAL FORCE, BENDING AND TORSION / REDUCTION RATIO OF TORSIONAL STIFFNESS / EQUIVALENT DAMPING RATIO / NONLINEAR FINITE ELEMENT ANALYSIS / RESTORATION CHARACTERISTICS |
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| Research Abstract |
During 2002 to 2004, the experimental research to clarify the hysteresis of reinforced concrete members subjected to axial forces, bending and torsional moments was conducted. Experimental parameters are constant axial forces, pitch of hoop lateral ties, and ratios of bending load to torsional load.
During 2005 to 2007, the experimental research was continued for concrete members subjected to two-axis bending moment, cyclic axial loading, and pure torsion. Furthermore finite element analysis is applied for theses experimental works. The followings are main results.
1) The effect of two-axis bending becomes remarkable for cases in which the bending are superior than torsion, therefore it would be not adequate if we use the bending -torsion interaction curve made by one- axis loading test data for the two- axis loading case.
2) The effect of cyclic axial loading clearly appear in the shape of hysteresis loop and skeleton curve. For the case in which bending and axial force increase simultaneously, the shape of hysteresis become sharp and maximum strength become large.
3) According to the increasing of damage torsional rigidity and damping ratios changed. These values are formulated using results of 30 test specimen to use the equivalent linear analysis.
4) Nonlinear finite element analysis is successfully used for the simulation of load and deflection curves.
5) The skeleton for the case of the cyclic pure torsion proposed in previous research is not sufficient and accurate. So new skeleton is proposed using the test results obtained by our experiments.
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