| Project/Area Number |
16K07804
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Wood science
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| Research Institution | Utsunomiya University |
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Principal Investigator |
Nakajima Shiro 宇都宮大学, 地域デザイン科学部, 教授 (00344010)
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| Co-Investigator(Kenkyū-buntansha) |
中川 貴文 京都大学, 生存圏研究所, 准教授 (60414968)
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2018: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2017: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2016: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
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| Keywords | 接合部 / 接合具径 / 荷重比 / 長期継続荷重載荷試験 / クリープ破壊 / モデル化 / 粘弾性体 / せん断破壊 / 割裂破壊 / 長期荷重載荷試験 / 短期加力試験 / 標準状態 / 木質構造 / 水分作用 |
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| Outline of Final Research Achievements |
Small clear test specimens with different width to pin-diameter ratio (l/d) were loaded for creep rapture. Time to failure was discussed in terms of the effect of length to pin-diameter ratio and the effect of moisture. The time to failure of the test specimens with l/d from 6.7 to 10 was longer and that of the test specimens with l/d from 4.3 to 6 was shorter than the time to failure estimated by the Madison Curve. The test results indicated that the duration of load factor for the tested joints should be evaluated with consideration of the effect of the width to pin-diameter ratio.
The joints were modeled to estimate the time to failure of the joints. The wooded materials composing the joints were modeled as an aggregation of viscoelastic elements. The time to failure of the joints were estimated on the assumption that the accumulation of the failure of the elements leads the failure of the joints. The test results were traced with the estimated results.
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| Academic Significance and Societal Importance of the Research Achievements |
木質構造の架構の耐力や剛性は多くの場合、接合部の性能で決まり、架構のクリープ破壊性状も接合部によって決まることが多いと考えられる。しかしながら、接合部の長期荷重に対する性能、とりわけクリープ破壊に関する性状については、既往の研究が少ない。例えば，継続して荷重が作用する接合部がどれくらいの期間でクリープ破壊に至るかなどについては未だ明らかになっていない点がある。本研究で得られた成果は、これまで知見がほとんどなかった木質構造の接合部のクリープ破壊に関する知見を示すもので、その学術的な意義は高い。また、木造建築物の構造安全性を確保することにおいて、その社会的な意義は高い。
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