Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
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Strength of Stainless Steel Pin-reinforced Composite Single-lap Joints

금속 핀으로 보강된 복합재 단일겹침 체결부의 강도 연구

  • 이병희 (경상대학교 대학원 항공우주공학전공) ;
  • 박용빈 (경상대학교 대학원 항공우주공학전공) ;
  • 권진회 (경상대학교 항공우주시스템공학과, 항공기부품기술연구소) ;
  • 최진호 (경상대학교 기계공학부, 항공기부품기술연구소) ;
  • 최익현 (한국항공우주연구원) ;
  • 장성태 (경상대학교 항공기부품기술연구소)
  • Published : 2012.06.30
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Abstract

The main objective of this study is to investigate the effect of metal z-pinning on the failure behavior of cocured composite single-lap joints. Three different pin diameters (0.3, 0.5, and 0.7 mm) and three pin areal densities (0.5, 2.0, and 4.0%) were examined. The specimens were fabricated by T700-12K-31E#2510 unidirectional prepreg from Toray. Stainless steel pins were used for z-pinning. Test results showed that except one case with extremely low pin density of 0.5%, all other z-pinned joints exhibited lower initial crack stresses than those of the unpinned joint. However the ultimate strength of the z-pinned joint increased up to 45% at most. Furthermore, even after the complete failure of the joint, the z-pins sustained the carried load to a certain degree experiencing large deformation and provided the stable fracture behavior for the composite joint.

본 논문에서는 금속 핀으로 보강된 일체성형 복합재 단일겹침 체결부에 대해, 보강 핀이 체결부의 파손거동에 미치는 영향을 시험으로 연구하였다. 핀의 지름(0.3, 0.5, 0.7 mm)과 밀도(0.5, 2.0, 4.0%)를 달리하여 총 6종류의 시편을 제작하였다. 복합재료와 보강핀은 각각 Toray사의 일방향 탄소-에폭시 프리프레그 T700-12K-31E#2510와 스테인리스 강이다. 핀 밀도가 매우 낮은 한 경우(0.5%)를 제외하고는, 모든 체결부에서 두께방향 핀의 보강으로 인해 초기균열의 발생이 더 빨라지는 것으로 나타났다. 그러나 극한강도는 최대 45%까지 증가하고, 특히 접착면의 완전한 분리 후에도 대변형 상태에서 핀이 추가적인 하중을 지지함으로써, 구조물이 안정적 파괴거동을 갖도록 하는 것을 확인하였다.

Keywords

References

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