2022 Fiscal Year Final Research Report

Research and development on core manufacturing technology of passive vibration-free system using post-buckling behavior of tape-shaped shape memory alloy element.

Research Project

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Project/Area Number	20K04164
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 18010:Mechanics of materials and materials-related
Research Institution	The University of Kitakyushu
Principal Investigator	Cho Hiroki 北九州市立大学, 国際環境工学部, 准教授 (00435421)
Co-Investigator(Kenkyū-buntansha)	戸部裕史国立研究開発法人宇宙航空研究開発機構, 宇宙科学研究所, 助教 (40743886) 佐々木卓実北九州市立大学, 国際環境工学部, 准教授 (80343432)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	形状記憶合金 / 座屈変形 / 負剛性 / 除振装置 / Ti-Ni合金 / Cu-Al-Mn合金
Outline of Final Research Achievements	The negative stiffness characteristics exhibited by shape memory alloys (SMA) during post-buckling deformation are useful for vibration isolators. In this study, the effects of material shape and cross-sectional shape of SMA on negative tangential stiffness value during post-buckling deformation were investigated to establish a design calculation technique for the vibration isolators. As a result, it was found that the negative tangential stiffness in post-buckling deformation can be calculated using the material's physical properties (Young's modulus and stiffness at plateau stress during stress-induced martensitic transformation) and slenderness ratio. It was also found that the negative tangential stiffness can be varied by adding curvature to the cross-section of the material. Furthermore, we found that Cu-Al-Mn SMA is suitable for vibration isolators, and investigated its buckling fatigue properties and functional degradation characteristics.
Free Research Field	材料工学
Academic Significance and Societal Importance of the Research Achievements	本研究の成果により、形状記憶合金の座屈後の負剛性の接線剛性値が材料の物性値と材料形状(細長比)により設計計算可能であることを明らかにした。また材料断面に曲率を付与することでも接線剛性値を変化させることが可能であり、この技術により、除振装置として板状SMA素子を使用する場合の形状設計の幅を大きく拡大させることができた。また、除振装置としてCu-Al-Mn形状記憶合金か非常に適していることを見出した。現在、得られた技術を用いて実際にSMAを用いた除振装置を試作、その特性評価を行っている。