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Optimization of connection detail of welded beam end based on the prediction approach of brittle fracture

Research Project

Project/Area Number 19K04699
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Review Section Basic Section 23010:Building structures and materials-related
Research InstitutionSojo University

Principal Investigator

AZUMA Koji  崇城大学, 工学部, 教授 (80320414)

Co-Investigator(Kenkyū-buntansha) 岩下 勉  有明工業高等専門学校, 創造工学科, 教授 (10332090)
Project Period (FY) 2019-04-01 – 2023-03-31
Project Status Completed (Fiscal Year 2022)
Budget Amount *help
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2021: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2020: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2019: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords鋼構造 / 溶接接合部 / 脆性破壊 / 接合部詳細 / スカラップ / 破壊評価 / 塑性拘束 / 建築構造・材料
Outline of Research at the Start

兵庫県南部地震以後,スカラップ形状の改良を目的とした実験研究が行われ,多様な形状が提案された.JASS6型と呼ばれる標準形状が示されて以降,開先カッターの普及と共に,それ以外の形状は殆ど使用されていない.しかし,JASS6型のスカラップではスカラップ底のひずみ集中が緩和されず,そこから延性き裂が発生・進展し脆性破壊に至ることがある.スカラップ底に発生したき裂周囲の塑性拘束は比較的高い.そのようなき裂に対しては,既に提案している評価手法で的確に脆性破壊を予測できることを確認している.そこで,様々なスカラップ形状をもつ試験体にこの破壊予測手法を応用し,脆性破壊の発生を最も抑制する形状を見出す.

Outline of Final Research Achievements

This study concerns the applicability of modified weld access holes and the partial cutting fillet welds (PCFW) procedure in assembled I-section beam. It was investigated that the suitable shape of weld access hole which could be used in the field-welded connection, using by experiment and FE analysis. The cyclic loading tests using beam-to-diaphragm joint models, which were designated to represent beam-to-column connections with through diaphragm, were conducted. The ductile cracks initiated at the toes of the submerged arc welding with experimental results showed the improved beams copes had sufficient deformation capacity. The maximum moment of the welded joint with a conventional or improved configuration was predicted using two evaluating procedures for brittle fractures. A comparison of the connection strengths demonstrated that the improvement in the shape of the weld access holes, and the leg length of welding affected the optimization of the connection details.

Academic Significance and Societal Importance of the Research Achievements

兵庫県南部地震直後には,鉄骨建物の柱梁接合部におけるスカラップ底からの脆性破壊が注目され,震災後,複合円型のスカラップが推奨されたが,その後の研究により,複合円型ではスカラップ底のひずみ集中は緩和されず,脆性破壊に至る可能性が示唆されており,破壊回避策は未だに確立されていない.今後,予想される巨大地震が発生する前に,これを解決した接合部詳細を確立することは,建物の安全性を担保する上で,大きな意義がある.本研究で用いた改良スカラップとウェブの薄肉化(脚長の最小化)により,スカラップ底へのひずみ集中を回避でき,更に梁フィレット部の隅肉溶接止端に沿った延性き裂の進展によりエネルギー散逸が期待できる.

Report

(5 results)
  • 2022 Annual Research Report   Final Research Report ( PDF )
  • 2021 Research-status Report
  • 2020 Research-status Report
  • 2019 Research-status Report
  • Research Products

    (29 results)

All 2023 2022 2021 2020 2019

All Journal Article (10 results) (of which Peer Reviewed: 10 results,  Open Access: 2 results) Presentation (19 results) (of which Int'l Joint Research: 6 results)

  • [Journal Article] Improvement of weld details to avoid brittle fracture initiating at the toes of weld access hole of the beam end - prediction of ultimate strength of welded joint with conventional detail2022

    • Author(s)
      Azuma Koji、Iwashita Tsutomu、Itatani Toshiomi
    • Journal Title

      Welding in the World

      Volume: 66 Issue: 9 Pages: 1929-1939

    • DOI

      10.1007/s40194-022-01299-0

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Brittle fracture estimation at ends of groove welded joints under cyclic loading2022

    • Author(s)
      Iwashita, T., Hamasaki, M., Akahoshi, T., Azuma, K.
    • Journal Title

      Journal of Constructional Steel Research

      Volume: 189 Pages: 107055-107055

    • DOI

      10.1016/j.jcsr.2021.107055

    • Related Report
      2022 Annual Research Report 2021 Research-status Report
    • Peer Reviewed
  • [Journal Article] シャルピー吸収エネルギーを用いた累積塑性変形能力推定の試み2022

    • Author(s)
      江島尚,赤木優羽,岩下勉,東康二,赤星拓哉
    • Journal Title

      鋼構造年次論文報告集

      Volume: 30 Pages: 615-623

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Study on Establish a Brittle Fracture Prediction Considering Different Crack Opening Modes Using Mixed-Mode Ratio2021

    • Author(s)
      Akahoshi, T., Azuma, K., Iwashita, T., Itatani, T.
    • Journal Title

      Applied Mechanics

      Volume: 2 Issue: 4 Pages: 849-862

    • DOI

      10.3390/applmech2040049

    • Related Report
      2021 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] 破壊靭性が異なる鋼試験片の脆性破壊発生時の累積塑性変形推定2021

    • Author(s)
      田島やよい, 岩下 勉, 江島 尚, 東 康二
    • Journal Title

      鋼構造年次論文報告集

      Volume: 29 Pages: 240-247

    • Related Report
      2021 Research-status Report
    • Peer Reviewed
  • [Journal Article] 梁フランジ溶接止端における脆性破壊発生時の累積塑性変形推定2021

    • Author(s)
      濱崎瑞生, 岩下 勉, 東 康二
    • Journal Title

      鋼構造年次論文報告集

      Volume: 29 Pages: 638-645

    • Related Report
      2021 Research-status Report
    • Peer Reviewed
  • [Journal Article] 溶接始終端部のき裂開口モードの違いが脆性破壊発生に及ぼす影響を捉えるための基礎的研究2021

    • Author(s)
      赤星拓哉, 東 康二, 岩下 勉
    • Journal Title

      鋼構造年次論文報告集

      Volume: 29 Pages: 682-688

    • Related Report
      2021 Research-status Report
    • Peer Reviewed
  • [Journal Article] 溶接欠陥から発生する脆性破壊のワイブル応力による予測2020

    • Author(s)
      濵﨑 瑞生,岩下 勉,東 康二
    • Journal Title

      鋼構造年次論文報告集

      Volume: 28 Pages: 460-468

    • Related Report
      2020 Research-status Report
    • Peer Reviewed
  • [Journal Article] 破壊靱性の異なる鋼試験片の切欠きから発生する脆性破壊予測2020

    • Author(s)
      岩下 勉,東 康二
    • Journal Title

      鋼構造年次論文報告集

      Volume: 28 Pages: 974-981

    • Related Report
      2020 Research-status Report
    • Peer Reviewed
  • [Journal Article] Prediction of brittle fracture in notched specimens under cyclic loading2019

    • Author(s)
      Iwashita, T., Azuma, K.
    • Journal Title

      Journal of Constructional Steel Research

      Volume: 162 Pages: 1-15

    • DOI

      10.1016/j.jcsr.2019.105721

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access
  • [Presentation] Improvement of weld details to avoid brittle fracture at the I-section beam-to-square hollow section column connections2023

    • Author(s)
      Azuma, K.
    • Organizer
      Hungary-Korea-Japan Joint Seminar on Design, Fabrication, and Maintenance of Welded Steel Structures
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 繰返し載荷を受ける切欠きを有する鋼試験片の累積塑性変形能力の推定に関する研究(その1)片側振幅が脆性破壊に与える影響2023

    • Author(s)
      赤木優羽,江島尚,岩下勉,赤星拓哉,東康二
    • Organizer
      日本建築学会九州支部
    • Related Report
      2022 Annual Research Report
  • [Presentation] 繰返し載荷を受ける切欠きを有する鋼試験片の累積塑性変形能力の推定に関する研究(その2)シャルピー吸収エネルギーを用いた推定手法の検討2023

    • Author(s)
      江島尚,赤木優羽,岩下勉,赤星拓哉,東康二
    • Organizer
      日本建築学会九州支部
    • Related Report
      2022 Annual Research Report
  • [Presentation] Optimization of shapes of weld access holes at the end of I-section beams based on the prediction approach for brittle fracture2022

    • Author(s)
      Gotanda, S., Azuma, K., Iwashita, T., Itatani, T.
    • Organizer
      32nd International Ocean and Polar Engineering Conference
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] シャルピー吸収エネルギーと3点曲げ試験における破壊靭性Jcの関係およびワイブル応力に関する研究2022

    • Author(s)
      江島尚, 岩下勉, 東康二, 赤星拓哉
    • Organizer
      日本建築学会九州支部
    • Related Report
      2021 Research-status Report
  • [Presentation] 曲げとせん断を同時に受けるき裂材のモード混合率に関する解析的検討2022

    • Author(s)
      志水昌樹, 赤星拓哉, 東 康二
    • Organizer
      日本建築学会九州支部
    • Related Report
      2021 Research-status Report
  • [Presentation] 繰返し負荷を受ける切欠きを有する鋼試験片のJ積分値を用いた脆性破壊予測手法に関する検討2022

    • Author(s)
      田島やよい, 岩下勉, 東康二
    • Organizer
      日本建築学会九州支部
    • Related Report
      2021 Research-status Report
  • [Presentation] Weibull stress approach considering a mixed-mode problem for prediction of brittle fracture from notches at the butt weld of the beam end2021

    • Author(s)
      Akahoshi, T., Azuma, K., Iwashita, T., Ibe, Y.
    • Organizer
      31st International Ocean and Polar Engineering Conference
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research
  • [Presentation] Improvement of weld details to avoid brittle fracture initiating at the toes of weld access hole of the beam end2021

    • Author(s)
      Azuma, K., Iwashita, T., Itatani, T.
    • Organizer
      IIW Annual Assembly
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research
  • [Presentation] 溶接始終端部のき裂開口モードの違いが脆性破壊発生に及ぼす影響を捉えるための基礎的研究2021

    • Author(s)
      赤星拓哉, 東康二, 岩下勉, 板谷俊臣
    • Organizer
      日本建築学会
    • Related Report
      2021 Research-status Report
  • [Presentation] 溶接継手梁フランジ開先面の融合不良から発生する脆性破壊の予測に関する研究2021

    • Author(s)
      岩下勉, 濵﨑瑞生, 赤星拓哉, 東康二
    • Organizer
      日本建築学会
    • Related Report
      2021 Research-status Report
  • [Presentation] 溶接始終端部の欠陥から発生する脆性破壊の予測に関する研究 繰返し載荷を受ける試験体の塑性変形能力推定2021

    • Author(s)
      濵﨑 瑞生,岩下 勉,東 康二
    • Organizer
      日本建築学会
    • Related Report
      2020 Research-status Report
  • [Presentation] 繰返し負荷を受ける切欠きを有する鋼試験片の脆性破壊に関する研究 温度変化による破壊靱性の違いが脆性破壊に及ぼす影響2021

    • Author(s)
      田島 やよい,岩下 勉,東 康二
    • Organizer
      日本建築学会
    • Related Report
      2020 Research-status Report
  • [Presentation] 繰返し載荷を受ける切欠きを有する鋼試験片の塑性変形能力に関する研究 その6 破壊靱性および試験温度の違いによる検討2020

    • Author(s)
      岩下 勉,東 康二
    • Organizer
      日本建築学会
    • Related Report
      2020 Research-status Report
  • [Presentation] Prediction of brittle fracture of at the Toes of Weld Access Hole of the welded I-section Beam End2019

    • Author(s)
      Wang, J., Azuma, K., Iwashita, T., Itatani, T.
    • Organizer
      International Offshore and Polar Engineering Conference
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] Prediction of Brittle Fracture at the Crack tips of Improved Weld Access Hole of Full-scale Beam-to-Column Assembly2019

    • Author(s)
      Jimbo, S., Azuma, K., Itatani, T., Nikaido, M.
    • Organizer
      International Offshore and Polar Engineering Conference
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] Improvement of the Work Efficiency and Optimization of the Material Properties in Heating Correction Processes of Welded I-section Steels2019

    • Author(s)
      Azuma, K., Yasuda, S., Itatani, T., Nakamura, Y., Murayama, M.
    • Organizer
      International Institute of Welding
    • Related Report
      2019 Research-status Report
  • [Presentation] A Study on Occurrence of Brittle Fracture of Steel Notched Specimens under Cyclic Loading with Different Fracture Toughness2019

    • Author(s)
      Matsuda, F., Iwashita, T., Azuma, K.
    • Organizer
      International Symposium on Plasticity and Impact Mechanics
    • Related Report
      2019 Research-status Report
  • [Presentation] Effects of Cyclic Loading on Plastic Deformation Capacity for Notched Specimens with Brittle Fracture2019

    • Author(s)
      Iwashita, T., Azuma, K.
    • Organizer
      The Pacific Structural Steel Conference
    • Related Report
      2019 Research-status Report

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Published: 2019-04-18   Modified: 2024-01-30  

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