2020 Fiscal Year Final Research Report

Improvement in mechanical properties and fatigue life of CFRTP due to an addition of sub-micron glass fibers and their mechanisms

Research Project

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Project/Area Number	18H01343
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 18010:Mechanics of materials and materials-related
Research Institution	Doshisha University
Principal Investigator	Fujii Toru 同志社大学, 研究開発推進機構, 嘱託研究員 (20156821)
Co-Investigator(Kenkyū-buntansha)	小武内清貴同志社大学, 理工学部, 准教授 (30614367) 大窪和也同志社大学, 理工学部, 教授 (60319465)
Project Period (FY)	2018-04-01 – 2021-03-31
Keywords	微細ガラス繊維 / 炭素繊維 / CFRTP / CFRP / 熱可塑エポキシ樹脂 / SMC / 耐衝撃性 / ポリプロピレン
Outline of Final Research Achievements	First, the effect of submicron glass fiber (sGF) addition to the VE matrix of C-SMC having various chopped carbon fibers was investigated. However, except for the impact strength, stable performance improvement of mechanical characteristics including fatigue life was not obtained due to sGF addition. High molecular weight thermos-plastic epoxy (TP-EP) having almost the same basic molecular structure as the thermosetting epoxy (TS-EP), CFRTP whose mechanical performance is comparable to TS-EP CFRP was obtained. The key to the performance of this material is the adhesive strength in CF/EP interface. We have developed a FRTP unidirectional tape with 3% sGF added to PP and a laminated board using this tape. In CFPP, the addition of sGF significantly improves impact resistance. The hemispherical molded product can bring out its maximum characteristics. CFTP using TP-EP significantly improved the CAI strength. This is due to an introduction of many fracture origins by sGF.
Free Research Field	材料力学
Academic Significance and Societal Importance of the Research Achievements	C-SMCの母材にsGFを添加することで，耐衝撃性能のみが確実に向上したが，短繊維CF強化のC-SMCでは，その価値は高い．熱可塑と熱硬化樹脂を同一樹脂で比べた研究は無く，樹脂の特性が異ならないなら，界面接着特性がPMCの性能を支配することが改めて確認できた．PPを母材とするCFPPでは，sGF添加一方向CFPPテープおよびこれを使った積層板が開発できた．sGF添加は積層板の機械的特性の中，衝撃強度を顕著に向上させる．そのメカニズムを基に，その特性を生かす成形品形状も見出した．TP-EPを用いたFRTPでは，sGF添加により，耐久性，特にCAIが顕著に高まること，そのメカニズムを解明した．