Delamination repair of CFRTP using 4D pinpoint eddy current method and elucidation of its melting mechanism

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K14850
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 18010:Mechanics of materials and materials-related
• Research Institution: Suzuka National College of Technology
• Principal Investigator: TOSHIYA ITAYA 鈴鹿工業高等専門学校, その他部局等, 准教授 (00650425)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: CFRTP / 渦電流 / 層間剥離 / 欠陥修復

Outline of Final Research Achievements

This study shows that it is possible to repair defects in thermoplastic carbon fiber reinforced plastic (CFRTP) using the newly developed four-dimensional pinpoint eddy current method and obtain sufficient strength in practical use. 　　First, using this eddy current method, it was confirmed that the three-dimensional CFRTP was melted at the targeted location. Next, it was shown that the delamination generated by the falling ball impact test was fused under heat and pressure, and the tensile strength was restored by the fusion. It was found that if the fibers of CFRTP were broken, cracks in the pellets were formed, or the parts other than the separated parts were melted too much, the strength would decrease. In addition, the internal state of CFRTP was investigated by X-ray CT, and the distribution of voids due to the influence of heating time was clarified.

Free Research Field

非破壊検査

Academic Significance and Societal Importance of the Research Achievements

熱可塑性炭素繊維強化プラスチック(以下、CFRTP)は、単工程で最終形状へ成形加工するため複雑形状品に対応できる。CFRTP成形品として、自動車車体や小型風力ブレードに利用されており、２次元でなく実用的に３次元のCFRTPの剥離修復の技術開発が期待されている。現在、複雑形状のCFRTPの剥離修復まで適用可能な技術は実用化されておらず、本技術を高度化することで、ピンポイントかつ立体形状のCFRTPの剥離修復まで適用可能できる可能性を示した。そして、CFRTPに発生した剥離を事前に修復することで、力学的強度低下を防ぎ安全性の維持やCFRTP品の再利用といった長寿命化に寄与できる。