SiO₂및 GNPs 보강 접착제를 적용한 Co-curing 복합재 접합부의 접착 강도 특성 비교

다국어 초록 (Multilingual Abstract)

High-performance composite structures and effective joining processes are critical for ensuring reliability in extreme environments, such as those found in the aerospace and automotive industries.
This study aims to investigate the effects of nanoparticle geometry (SiO₂ and Graphene Nanoplatelets (GNPs)) and content on the rheological properties, mechanical strength, and fracture behavior of co-cured Glass Fiber Reinforced Plastic (GFRP) Single Lap Joints (SLJs).
Experimental results demonstrated distinct differences in mechanical performance based on the fabrication process.
Joints fabricated using the co-curing (CC) technique exhibited significant improvements in shear and flexural strengths of approximately 35.19% and 12.00%, respectively, compared to those made via secondary bonding (SB).
This enhancement is attributed to the strengthened interfacial bonding achieved through the integration of the laminate and adhesive during the co-curing process.
Furthermore, significant reinforcement effects were observed with the addition of nanoparticles.
Both particle types exhibited optimal mechanical performance at a content of 0.75 wt.%. Notably, GNPs, characterized by a high aspect ratio, demonstrated superior reinforcement efficiency compared to SiO₂ nanoparticles.
Specifically, the addition of SiO₂ and GNPs improved shear strength by approximately 35.67% and 43.09%, and flexural strength by 25.09% and 28.06%, respectively.
Rheological analysis revealed that although GNPs induced a greater increase in viscosity than SiO₂, stable processability was maintained up to a content of 1.0 wt.%.
Regarding mechanical performance, GNPs reinforced the adhesive interface through effective mechanisms such as crack bridging and pull-out.
Fracture surface analysis indicated a transition in failure mode from adhesive failure to cohesive or substrate failure at the optimal content, verifying improved adhesion between the matrix and fibers.
In conclusion, this study demonstrates that the incorporation of 2D platelet-shaped GNPs with high specific surface area at an optimal content of 0.75 wt.% significantly enhances the structural integrity of cocured GFRP joints.

목차 (Table of Contents)

• 1. 서론 1
• 1.1. 연구배경 1
• 2. 실험 및 방법 5
• 2.1. 실험 재료 5
• 2.2. 시편 제조 7
• 2.2.1. 실험 시편 변수 7
• 2.2.2. 에폭시 기지 내 나노입자 분산 8
• 2.2.3. 2 차 접합 공정을 이용한 복합재 접합부 제작 10
• 2.2.4. 공동 경화 공정을 이용한 복합재 접합부 제작 13
• 2.3. 점도 분석 16
• 2.4. 접합부 전단 강도 평가 17
• 2.5. 접합부 3점 굽힘 시험 20
• 2.6. 파단면 분석 23
• 2.7. 미세 구조 분석 24
• 3. 결과 및 고찰 25
• 3.1. 나노입자 함량에 따른 점도 특성 25
• 3.2. 접합부의 기계적 특성 29
• 3.2.1. 제조 공정에 따른 영향 29
• 3.2.2. 나노입자 함량에 따른 영향 32
• 3.3. 거시적 파단면 분석 39
• 3.3.1. 제조 공정에 따른 파괴 양상 비교 39
• 3.3.2. 나노입자 함량에 따른 파괴 양상 변화 42
• 3.4. 미세 구조 및 강화 메커니즘 50
• 3.4.1. SiO2 나노입자의 미세 구조 및 강화 메커니즘 50
• 3.4.2. GNPs 의 나노입자 미세 구조 및 강화 메커니즘 54
• 4. 결론 58
• 참고문헌 60
• Abstract 65