| Project/Area Number |
19H02028
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 18010:Mechanics of materials and materials-related
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| Research Institution | Hiroshima University |
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Principal Investigator |
SUGETA ATSUSHI 広島大学, 先進理工系科学研究科(工), 教授 (60162913)
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| Co-Investigator(Kenkyū-buntansha) |
小山 敦弘 長崎大学, 工学研究科, 准教授 (40324800)
曙 紘之 広島大学, 先進理工系科学研究科(工), 教授 (50447215)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥17,680,000 (Direct Cost: ¥13,600,000、Indirect Cost: ¥4,080,000)
Fiscal Year 2021: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2020: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2019: ¥11,570,000 (Direct Cost: ¥8,900,000、Indirect Cost: ¥2,670,000)
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| Keywords | 疲労損傷機構 / 異材接合材 / 微視的観察 / き裂発生 / 疲労寿命評価 / 疲労き裂進展 / 微視的内部観察 / き裂進展 / マルチマテリアル / 摩擦攪拌接合 / 接着接合 / 疲労き裂発生 / 異材継手 / 疲労強度 / 破壊機構 / 接合技術 |
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| Outline of Research at the Start |
摩擦撹拌技術を援用した金属/FRP異材接合体を用いて，疲労き裂発生ならびにき裂進展挙動のナノスケール損傷その場観察を行い，異材接合体の疲労損傷発達機構を明らかにする．摩擦撹拌技術援用の金属/FRP異材接合体の強度特性は接合時のツールピンの回転数，押し込み速度，保持時間などに顕著な依存性を示すことが考えられるため，これらの条件を実験計画法により割り振った種々の異材接合体を用いて疲労試験ならびに内部損傷観察を行い，接合体の疲労損傷発達機構を明らかにすることで，その損傷発現を抑制する最適な接合技術の開発を行う．
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| Outline of Final Research Achievements |
As lightweight multi-material joint, fatigue tests were conducted using friction stirring joints and weld-bond combined joints for Al / CFRP and Al wrought materials / Al die-cast materials, and adhesive joints for iron-based joints, and their damage mechanisms were evaluated. In all materials, it was clarified that the occurrence of fatigue cracks from the interface tip of the contact part of the base material was the main factor of fracture, and the weak part could be strengthened in the weld-bond combined joint, so the strength could be improved. In the adhesive joint, the effect of water deterioration was investigated, and it was clarified that the main factor of the decrease in strength was the decrease in interface strength due to the rust generated at the interface. The secondary factor was the water deterioration phenomenon of the adhesive, and it was clarified that the crack growth rate was significantly accelerated by being immersed in water for about 3 weeks.
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| Academic Significance and Societal Importance of the Research Achievements |
軽量マルチマテリアル車体の実現のための異材接合継手の強度評価ならびに損傷機構の解明を行った．特に微視的連続観察により，接合体母材界面の先端部が弱部となりそれを起点としてき裂が発生し，その他の損傷と連成する損傷機構メカニズムが解明できた．また，接着剤については水劣化の影響を調べ，界面強度の低下と接着剤自信の劣化を分離して強度評価を行った結果は，これまでなく学術的意義は大きい．各種接合材についての損傷メカニズムが解明できたことにより，それらの発現を極力抑制する接合技術開発への指針を提案できたことは社会的意義も大きい．
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