Development and design of bolted joint and stiffening plate repair with high load capacity and ductility

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14233
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22020:Structure engineering and earthquake engineering-related
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Takai Toshikazu 九州工業大学, 大学院工学研究院, 准教授 (00759433)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 高力ボルト継手 / 当て板補修 / 終局挙動 / 最大荷重 / エネルギー吸収

Outline of Final Research Achievements

In this study, the energy absorption in plastic deformation of high-strength bolted connections and stiffening plate repair with high-strength bolts was investigated to improve the load-carrying capacity and ductility of structures, assuming the application of extreme force due to an earthquake. The results of the energy absorption of bolted connections were organized, focusing on the ultimate mode of bolted connections in tension. It was found that the dimension of the bolted connection in the transition range between two ultimate modes gave high energy absorption. The prediction formulae of energy absorption were obtained by regression between the dimensions of bolted connections and energy absorption. The expected energy absorption of designed bolted connections can be obtained by the formulae.

Free Research Field

橋梁工学

Academic Significance and Societal Importance of the Research Achievements

高力ボルト摩擦接合継手と高力ボルト当て板補修部を対象に，過大な荷重が作用したときの最大荷重やそのときの伸び，エネルギー吸収量の傾向を最大荷重時の終局モードに着目して整理した．エネルギー吸収量が高くなる諸元の条件を明らかにし，諸元から期待されるエネルギー吸収量の予測式を求めた．この式によりエネルギー吸収量の高い諸元で設計することが可能となる．構造主部材の高力ボルト継手，当て板補修部以外にも，構造の似たエネルギー吸収部材への本知見の活用も考えられる．これらにより，粘り強い構造の実現につながると考えられる．