2019 Fiscal Year Final Research Report
Enhancing fatigue strength of welded joints made of steels for bridge high performance structures by considering its beneficial fatigue limit
| Project/Area Number |
17K06530
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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 |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | Gifu University |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Keywords | 橋梁用降伏点鋼板 / 疲労試験 / 残留応力 |
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| Outline of Final Research Achievements |
For steel bridges, an application of high strength steels has been known one of the effective approaches on weight reduction and cost saving for construction and transportation. According to the requirements, steels for bridge high performance structures (SBHS) developed newly in Japan have been recently focused on the application due to its higher strength and beneficial weld ability and work ability. However, it has been known that fatigue strength of welded joints may be independent of the steel tensile strength of base metal, which results in difficulty of using high strength steels to steel bridges efficiently. Therefore, fatigue strength of welded joints made of high strength steels must be enhanced.The evaluation results based on a model proposed in a previous study considering a unique parameter of this study in terms of fatigue limit of SBHS700 base plate may provide a better evaluation for lower limit of the fatigue test results.
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| Free Research Field |
破壊力学， 構造工学， 維持管理工学
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| Academic Significance and Societal Importance of the Research Achievements |
高強度鋼材の素材疲労試験データ蓄積に加えてき裂起点のミクロ・フラクトグラフィを基に√areaパラメータモデルの適用性を証明し，素材疲労強度を新たに提案・反映してHFMI処理された溶接継手の疲労強度評価の高度化を実証した点は極めて実証的である．従来の統計的な寸法効果の検討の多くは小型試験体などの継手形状が限られた疲労試験データを基に，単一の継手寸法を説明変数とした単回帰統計モデルにより評価されてきたが，従来データベースをより幅広い継手形状を検討可能かつ「全世界型」に更新した上で重回帰統計モデルを基に寸法効果を再評価した点は実証的である．
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