Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
권호 표지
DOI QR코드

DOI QR Code

Micromechanical Computational Analysis for the Prediction of Failure Strength of Porous Composites

다공성 복합재의 파손 강도 예측을 위한 미시역학 전산 해석

  • Yang, Dae Gyu (Department of Aerospace Engineering, Chonbuk National University) ;
  • Shin, Eui Sup (Department of Aerospace Engineering, Chonbuk National University)
  • Received : 2016.01.03
  • Accepted : 2016.04.26
  • Published : 2016.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Porosity in polymer matrix composites increases rapidly during thermochemical decomposition at high temperatures. The generation of pores reduces elastic moduli and failure strengths of composite materials, and gas pressures in internal pores influence thermomechanical behaviors. In this paper, micromechanical finite element analysis is carried out by using two-dimensional representative volume elements for unidirectionally fiber-reinforced composites with porous matrix. According to the state of the pores, effective elastic moduli, poroelastic parameters and failure strengths of the overall composites are investigated in detail. In particular, it is confirmed that the failure strengths in the transvers and through-thickness directions are predicted much more weakly than the strength of nonpored matrix, and decrease consistently as the porosity of matrix increases.

고온에서 열화학적 분해 현상을 겪는 고분자 기지 복합재료는 기지 내부의 기공도가 급격히 증가한다. 기공의 생성은 재료의 탄성 계수와 파손 강도를 감소시키며, 기공 내부의 가스 압력은 재료의 열기계적 거동에 영향을 준다. 본 논문에서는 기지 내부에 많은 기공이 포함된 일방향 섬유 강화 복합재료의 이차원 대표 체적 요소를 설정하고 유한요소 해석을 수행하였다. 이를 통해 기공 상태에 따른 복합재료의 유효 탄성 계수, 기공 탄성 계수, 파손 강도 등을 산출하였다. 특히, 기지 재료의 특성에 많은 영향을 받는 섬유 수직 방향의 파손 강도가 원래 기지 강도보다 현격히 낮게 산출되며, 기공도가 증가함에 따라 지속적으로 떨어지는 경향을 확인하였다.

Keywords

References

  1. Looyeh, M.R.E., Samata, A., Jihan, S., and McConnachie, J., "Modelling of Reinforced Polymer Composites Subject to Thermo-mechanical Loading," International Journal for Numerical Methods in Engineering, Vol. 63, No. 6, 2005, pp. 898-925. https://doi.org/10.1002/nme.1309
  2. Mcmanus, H.L.N. and Springer, G.S., "High Temperature Thermomechanical Behavior of Carbon-Phenolic and Carbon-Carbon Composites - I. Analysis," Journal of Composite Material, Vol. 26, No. 2, 1992, pp. 206-229. https://doi.org/10.1177/002199839202600204
  3. Mcmanus, H.L.N. and Springer, G.S., "High Temperature Thermomechanical Behavior of Carbon-Phenolic and Carbon-Carbon Composites - II. Results," Journal of Composite Materials, Vol. 26, No. 2, 1992, pp. 230-255. https://doi.org/10.1177/002199839202600205
  4. Yang, B.C., A Theoretical Study of Thermo-mechanical Erosion of High-Temperature Ablatives, Ph.D. Dissertation, Pennsylvania State University, 1992.
  5. Biot, M.A. and Willis, D.G., "The Elastic Coefficients of the Theory of Consolidation," Journal of Applied Mechanics, Vol. 24, 1957, pp. 594-601.
  6. Carroll, M.M., "An Effective Stress Law for Anisotropic Elastic Deformation," Journal of Geophysical Research, Vol. 84, No. B13, 1979, pp. 7510-7512. https://doi.org/10.1029/JB084iB13p07510
  7. Sullivan, R.M. and Salamon, N.J., "A Finite Method for the Thermochemical Decomposition of Polymeric Materials - I. Theory," International Journal of Engineering and Science, Vol. 30, No. 4, 1992, pp. 431-441. https://doi.org/10.1016/0020-7225(92)90035-F
  8. Wu, Y. and Katsube, N., "A Thermomechanical Model for Chemically Decomposing Composites - I. Theory," International Journal of Engineering Science, Vol. 35, No. 2, 1997, pp. 113-128. https://doi.org/10.1016/S0020-7225(96)00072-9
  9. Matsuura, Y. and Hirai, K., "A Challenge of Predicting Thermo-Mechanical Behavior of Ablating SiFRP with Finite Element Analysis," AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 49th, AIAA 2010-6975.

Cited by

  1. 요소 절단법을 사용한 섬유강화 복합재료의 대규모 통계적 체적 요소 모델 개발 vol.31, pp.5, 2016, https://doi.org/10.7234/composres.2018.31.4.251
  2. 단방향 연속 섬유 복합재 횡단면에서 섬유 배열에 따른 응력 분포 변화 vol.33, pp.1, 2016, https://doi.org/10.7234/composres.2020.33.1.030