DOI QR코드

DOI QR Code

Failure of composite sandwich joints under pull-out loading

풀아웃 하중을 받는 복합재 샌드위치 체결부의 파손거동 연구

  • 박용빈 (경상대학교 항공우주공학과) ;
  • 양현정 (경상대학교 항공우주공학과) ;
  • 권진회 (경상대학교 기계항공공학부.항공기부품기술연구소) ;
  • 최진호 (경상대학교 기계항공공학부.항공기부품기술연구소) ;
  • 조현일 (한국항공우주산업(주))
  • Published : 2011.02.28

Abstract

The failure of composite sandwich joints was experimentally investigated. A total of 30 joint specimens of 5 different types were tested with various fastening methods and core materials. In the NomexTM core sandwich joints, the core shear buckling was commonly observed in all the specimens which was followed by the slope change of the load-displacement curve. After the shear buckling, however, the joints carried additional loads of 50~200% over the buckling loads and then finally failed in the upper face breakage. The joints of PMI foam core showed the shear failure of the core instead of shear buckling and experienced the sharp drop of the carried load. Considering the failure modes, while both the core and face properties are important in the $Nomex^{TM}$ core joints, core shear strength seems to be the critical factor for the foam core joints.

풀아웃 하중을 받는 복합재 샌드위치 체결부의 파손 거동을 시험으로 연구하였다. 체결의 방식과 코어의 종류를 달리하여 5종류, 총 30개의 시편에 대해 시험을 수행하였다. 시험 결과, 노멕스 하니콤 코어를 사용할 경우 코어의 강성에 의해 지배되는 전단좌굴이 먼저 발생하고, 이후 50~200% 정도의 추가적인 하중을 지지하다가, 면재가 찢어지는 최종파손이 발생하였다. 반면에 PMI 폼을 사용하면 하중 초기에 코어의 전단파손이 발생하며 지지하중도 크게 저하되는 것을 확인하였다. 파손모드를 고려한 설계의 관점에서 볼 때, 노멕스 코어를 사용할 경우 코어의 강성과 면재의 강성 및 강도를 동시에 고려해야 하는 반면, 폼 코어를 사용할 경우 코어의 전단파손 하중을 높이는 것이 가장 중요한 것으로 나타났다.

Keywords

References

  1. Vinson, J. R., The Behavior of Sandwich Structures of Isotropic and Composite Materials, Technomic Pub. Co., Lancaster, PA, 1999.
  2. Karlsson, K. F. and Astrom, B. T., "Manufacturing and Application of Structural Sandwich Components," Composites Part A: Applied Science and Manufacturing, Vol. 28, 1997, pp. 97-111. https://doi.org/10.1016/S1359-835X(96)00098-X
  3. Mouritz, A. P. and Thomson, R. S., "Compression, Flexure and Shear Properties of A Sandwich Composite Containing Defects," Composite Structures, Vol. 44, 1999, pp. 263-278. https://doi.org/10.1016/S0263-8223(98)00133-0
  4. Avery, J. L. and Sankar, B. V., "Compressive Failure of Sandwich Beams with Debonded Face-Sheets," Journal of Composite Materials, Vol. 34, No. 14, 2000, pp. 1176-1199. https://doi.org/10.1177/002199830003401402
  5. Daniel, I. M., Gdoutos, E. E., Abot, J. L. and Wang, K. A., "Deformation and Failure of Composite Sandwich Structures," Journal of Thermoplastic Composite Materials, Vol. 16, No. 4, 2003, pp. 345-364. https://doi.org/10.1177/0892705703016004005
  6. Berkowitz, C. K. and Johnson, W. S., "Fracture and Fatigue Tests and Analysis of Composite Sandwich Structure," Journal of Composite Materials, Vol. 39, No. 16, 2005, pp. 1417-1431. https://doi.org/10.1177/0021998305050432
  7. Meyer-Piening, H. -R., "Sandwich Plates: Stresses, Deflection, Buckling and Wrinkling Loads - A Case Study," Journal of Sandwich Structures and Materials, Vol. 8, No. 5, 2006, pp. 381-394. https://doi.org/10.1177/1099636206064825
  8. Sue, J. W. and Whitcomb, J., "Effect of Sandwich Configuration on Behavior of Honeycomb Core," Journal of Sandwich Structures and Materials, Vol. 10, No. 4, 2008, pp. 311-329. https://doi.org/10.1177/1099636208090579
  9. Demelio, G., Genovese, K. and Pappalettere, C., "An Experimental Investigation of Static and Fatigue Behavior of Sandwich Composite Panels Joined by Fasteners," Composites Part B: Engineering, Vol. 32, 2001, pp. 299-308. https://doi.org/10.1016/S1359-8368(01)00007-5
  10. Kim, B. J. and Lee, D. G., "Characteristics of Joining Inserts for Composite Sandwich Panels," Composite Structures, Vol. 86, 2008, pp. 55-60. https://doi.org/10.1016/j.compstruct.2008.03.020
  11. Song, K. I., Choi, J. Y., Kweon, J. H., Choi, J. H. and Kim, K. S., "An Experimental Study of the Insert Joint Strength of Composite Sandwich Structures," Composite Structures, Vol. 86, 2008, pp. 107-113. https://doi.org/10.1016/j.compstruct.2008.03.027
  12. Feldhusen, J., Warkotsch, C. and Kempf, A., "Development of A Mechanical Technology for Joining Sandwich Elements," Journal of Sandwich Structures and Materials, Vol. 11, No. 6, 2009, pp. 471-486. https://doi.org/10.1177/1099636209105378
  13. Raghu, N. and Battley, M., "Strength Variability of Inserts in Sandwich Panels," Journal of Composite Materials, Vol. 11, No. 6, 2009, pp. 501-517.
  14. 김광수, 안재모, 장영순, 이영무, "복합재 샌드위치 구조의 인써트 조인트의 강도 향상," 한국복합재료학회지, 제38권 제1호, 2009, pp. 29-34.
  15. Heimbs, S. and Pein, M., "Failure Behavior of Honeycomb Sandwich Comer Joints and Inserts," Composite Structures, Vol. 89, 2009, pp. 575-588. https://doi.org/10.1016/j.compstruct.2008.11.013

Cited by

  1. Testing and modeling of Nomex™ honeycomb sandwich Panels with bolt insert vol.56, 2014, https://doi.org/10.1016/j.compositesb.2013.09.006