| Project/Area Number |
16K18321
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Naval and maritime engineering
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| Research Institution | Osaka University |
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Principal Investigator |
Tatsumi Akira 大阪大学, 工学研究科, 助教 (60736487)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
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| Keywords | 縦曲げ最終強度 / 縦曲げ逐次崩壊解析 / 拡張Smith法 / 簡易推定法 / 船底局部荷重 / 二重底曲げ / 縦曲げ最終強度の簡易推定法 / 幅方向応力 / 縦曲げ逐次崩壊 / 二重底の局部曲げ / 船底外板での座屈の加速 / 内定板の有効性の低下 / 局部荷重 |
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| Outline of Final Research Achievements |
This study investigates ultimate longitudinal bending strength of container ships whose double bottoms are subjected to local loads such as water pressure and cargo load. The upward local loads make convex deflections of the double bottoms which could decrease the ultimate hogging strength of hull girders. The ultimate hull girder strength under combined the hogging moment and the local loads are analyzed by nonlinear finite element method.This analysis clarifies several main causes of ultimate strength reduction of the hull girder due to the local loads.
Based on knowledge obtained through the FE analysis, a practical method to analyze progressive collapse behavior of the hull girders subjected to combined the hogging moment and local loads is developed, which is named "extended Smith's method".In addition, a ultimate strength interaction formula is derived to more simply predict the ultimate hogging strength of the hull girder accompanied by the local loads.
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| Academic Significance and Societal Importance of the Research Achievements |
船底に働く局部荷重により船体のホギング状態での縦曲げ最終強度が低下することは知られていた。本研究にて行った非線形有限要素法による縦曲げ崩壊解析により、その低下をもたらす主要な原因（船底外板での座屈の加速と内底板の有効性の低下）が明らかとなり、学術的に新しい知見が得られた。一方、非線形有限要素法を用いた詳細な解析には多大な時間を要する。本研究では、局部荷重の影響を考慮して縦曲げ最終強度を推定できる実用的な解析手法ならびに最終強度相関関係式を提案した。これらの提案手法は迅速に縦曲げ崩壊挙動あるいは縦曲げ最終強度を求めることができ、船舶の基本設計にも十分に使用できるものである。
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