| Project/Area Number |
06838008
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
都市施設保全工学
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| Research Institution | kansai University |
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Principal Investigator |
SAKANO Masahiro Kansai University, Department of Civil Engineering, Associate Professor, 工学部, 助教授 (50143201)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | steel bridge / fatigue / super long life / plate girder / variable loading / design load / life avaluatin / cut-off limit / 強度等級 / 実験 / きれつ進展 / 寿命予測 |
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| Research Abstract |
Long-life variable amplitude fatigue tests are performed using plate girder specimens with full-sized connection details for transverse stiffeners, web penetrations and flange attachments.
(1) Fatigue cracks are initiated from the fillet weld toe at the stiffener end on both the tension side and compression side, from blow holes contained in web-to-flange longitudinal fillet welds, and from the transverse fillet weld toe of the patch plate on the compression flange. The fatigue failure life of all four details of the transverse stiffener connections satisfies JSSC category D.
(2) Fatigue strength of web penetration specimens, expressed by the principal stress, between the groove welded specimen and fillet welded ones can be estimated by an effect of the weld toe configurations on the stress distribution.
(3) Fatigue cracks are initiated from root gap and toe of transverse fillet weld between an attachment and a flange plate. Fatigue strength of the plate girder flange with a patch-plate-type attachment is demonstrated to be lower than the JSSC Category-F.
(4) A simulation analysis of traffic loading is performed to propose simultaneous loading factors for fatigue assessment of urban expressway bridges. As a result, the simultaneous loading factor for single lane can be presented simply by the function of only the bridge span and that for double lanes rather simply as the constant value.
(5) The linear cumulative damage rule using the cut-off limit regulated against Shinkansen-type variable amplitude stresses is found to give more than 30% under estimation for fatigue damage in some cases of bridge members.
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