Development of the long-term reliability evaluation technique of Steel/CFRP structural adhesive joint consisting of millimeters order thickness of adhesive layer for shipbuilding

Research Project

Project/Area Number	15K06629
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Naval and maritime engineering
Research Institution	National Institute of Maritime, Port and Aviation Technology
Principal Investigator	IWATA TOSHIAKI 国立研究開発法人海上・港湾・航空技術研究所, 海上技術安全研究所構造基盤技術系, 基盤技術研究グループ長 (50358397)
Project Period (FY)	2015-04-01 – 2018-03-31
Project Status	Completed (Fiscal Year 2017)
Budget Amount *help	¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000) Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2016: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000) Fiscal Year 2015: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Keywords	構造用接着剤 / 異種材接合 / 造船 / ミリオーダー接着層厚 / 耐久性評価 / 引張せん断強度 / CFRP / 鋼 / ＣＦＲＰ
Outline of Final Research Achievements	In shipbuilding, there are advantages such as the strength improvement by the adopting of the reinforcement members made of the CFRP by replacing the welded joint with the structural adhesive joint. However, it is demanded that the dimensional accuracy management of the members is at the same level as current welding, namely structural adhesive can fill the gap of the millimeter order. The lack of the knowledge for the long-term reliability of thick adhesive layer is obstacles to the practical use. In this study, accelerated deterioration test by high temperature high humidity, recovering test by the drying after water absorption, xenon exposure weatherability test, and salt water mist resistant test were carried out for evaluation using the deterioration estimate curve about the design adhesive strength in shipbuilding. As a result, it was revealed that the design strength where coefficient of dispersion is more than 0.4 and strength retention rate is more than 0.5 is appropriate.