Research on New Joining Method Using Rotational Friction Welding of Steel Structural Members

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04720
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 23010:Building structures and materials-related
• Research Institution: Setsunan University
• Principal Investigator: NISHIMURA KATSUHISA 摂南大学, 理工学部, 教授 (90826207)
• Co-Investigator(Kenkyū-buntansha): 向出 静司 大阪工業大学, 工学部, 准教授 (20423204)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 回転摩擦溶接 / 鉄骨造 / 継手

Outline of Final Research Achievements

Rotary friction welding joint in which a tapered plug (round steel bar) is inserted into a tapered joint steel plate hole, and the plug is subjected to pressing force and rotation to fill the joint steel plate hole by friction welding with the steel plate to be joined. The joining strength , stress transmission, and conditions for integration of the plug and steel plate were clarified by experiments and analysis.
By setting the pressing force per plug bottom area: 60 N / mm2 and the rotation speed of 3000 rpm, it is possible to secure the joining strength of about 0.6 times the tensile strength of the steel material. Further, by making the diameter of the bottom surface of the plug and the diameter of the hole of the joined steel material the same, it is possible to integrate the plug and the steel plate. Furthermore, we proposed a method for evaluating the strength of joint joints from a member experiment of a horizontal haunch beam with a joint by this method.

Free Research Field

鋼構造，耐震工学，構造計画

Academic Significance and Societal Importance of the Research Achievements

回転摩擦溶接接合工法による接合耐力，プラグと鋼板の一体化を図る条件，継手接合耐力評価の提案により，その特徴を生かし溶接接合部の塑性化を回避し変形性能の向上を目的とした水平ハンチ梁のブラケット長さを極端に短くした設計が可能となる．ブラケット製作の省力化，運搬コストの低減，梁端溶接部の破断リスク低減などのメリットが見込める．この接合技術は鉄骨部材接合において大きな優位性があり，技術を確立し実用化することが出来れば鉄骨構造の発展に寄与する．また，片側からの施工が可能であり，既存構造物の耐震補強に有効であり，地震が多発する現在，急務である建築・都市の耐震性向上を促進できる．