Multiple I-fiber Stitching 공법으로 보강한 십자형 복합재 체결부의 강도 평가 및 예측 = Strength Evaluation and Prediction of Cruciform Composite Joint Reinforced with Multiple I-fiber Stitching

다국어 초록 (Multilingual Abstract)

Delamination at interlaminar interfaces is a prevalent failure mode in composite structures subjected to mechanical loading, potentially resulting in catastrophic structural collapse. Conventional through-thickness reinforcement methods, such as Z-pinning and stitching, have been widely adopted to mitigate delamination and improve the out-of-plane mechanical performance of composite laminates. However, these techniques present inherent limitations in reinforcement efficiency. To address these challenges, a novel method termed I-fiber stitching has recently been introduced, and its applicability and effectiveness are under active investigation.In this study, cruciform composite joints reinforced with multiple I-fiber stitching were fabricated and evaluated through experimental testing. Corresponding finite element analyses (FEA) were conducted for validation purposes. In the numerical model, I-fiber reinforcements were represented using simplified spring elements, while adhesive interfaces were modeled using the cohesive zone method (CZM). The maximum deviation between the predicted and experimental failure loads was within 15.04%, indicating excellent correlation. The results demonstrate that the proposed FEA approach provides an accurate and efficient means for analyzing and predicting the structural performance of I-fiber-stitched composite laminates.

목차 (Table of Contents)

• Ⅰ. 서론 1
• 1. 연구 배경 1
• 2. 연구 목적 및 논문 구성 3
• 1) 연구 목적 3
• 2) 논문 구성 3
• Ⅱ. 시편 제작 및 시험 4
• 1. 시편 소재 및 제작 4
• 1) 시편 소재 4
• 2) 시편 형상 5
• 3) 금형 설계 7
• 4) 시편 제작 8
• 2. 시험 10
• 1) 시험 치구 설계 10
• 2) 시험 방법 11
• 3) 시험 결과 12
• 4) 시험 결과분석 17
• Ⅲ. 유한요소해석 21
• 1. 모델링 및 경계조건 21
• 2. CZM (Cohesive Zone Model) 24
• 3. 시험 결과와 해석 결과 비교 및 분석 26
• 1) No-Bonding 시편 26
• 2) Bonding 시편 29
• Ⅳ. 결론 33
• 참고문헌 34