A Study on the Fatigue Analysis of Glass Fiber Reinforced Plastics with Linear and Nonlinear Multi-Scale Material Modeling

선형과 비선형 다중 스케일 재료 모델링을 활용한 유리섬유 강화 플라스틱의 피로해석 연구

  • Kim, Young-Man (Department of Mechanical Engineering, Chungnam National Univ.) ;
  • Kim, Yong-Hwan (Department of Mechanical Engineering, Chungnam National Univ.)
  • 김영만 (충남대학교 기계공학부) ;
  • 김용환 (충남대학교 기계공학부)
  • Received : 2019.11.10
  • Accepted : 2020.01.18
  • Published : 2020.04.30


The fatigue characteristics of glass fiber reinforced plastic (GFRP) composites were studied under repeated loads using the finite element method (FEM). To realize the material characteristics of GFRP composites, Digimat, a mean-field homogenization tool, was employed. Additionally, the micro-structures and material models of GFRP composites were defined with it to predict the fatigue behavior of composites more realistically. Specifically, the fatigue characteristics of polybutylene terephthalate with short fiber fractions of 30wt% were investigated with respect to fiber orientation, stress ratio, and thickness. The injection analysis was conducted using Moldflow software to obtain the information on fiber orientations. It was mapped over FEM concerned with fatigue specimens. LS-DYNA, a typical finite element commercial software, was used in the coupled analysis of Digimat to calculate the stress amplitude of composites. FEMFAT software consisting of various numerical material models was used to predict the fatigue life. The results of coupled analysis of linear and nonlinear material models of Digimat were analyzed to identify the fatigue characteristics of GFRP composites using FEMFAT. Neuber's rule was applied to the linear material model to analyze the fatigue behavior in LCF regimen. Additionally, to evaluate the morphological and mechanical structure of GFRP composites, the coupled and fatigue analysis were conducted in terms of thickness.


  1. Adam, L., Depouhon, A., Assaker, R. (2008) Multi-scale Modeling of Crash & Failure of Reinforced Plastics Parts with Digimat to LS-DYNA Interface, 7th European LS-DYNA Conference.
  2. Bernasconi, A., Cosmi, F. (2008) Local Anisotropy Analysis of Injection Moulded Fibre Reinforced Polymer Composites, Compos. Sci. Technol, 68, pp.2574-2581.
  3. Bernasconi, A., Davoli, P., Basile, A. (2007) Effect of Fibre Orientation on the Fatigue behaviour of a Short Glass Fibre Reinforced Polyamide-6, Int. J. Fatigue, 29(2), pp.199-208.
  4. Biron, M. (2013) Thermoplastics and Thermoplastic Composites 2nd Edition, William Andrew, Massachusetts, p.1164.
  5. Brunbauer, J., Mosenbacher, A. (2014) Fundamental Influences on Quasistatic and Cyclic Material Behavior of Short Glass Fiber Reinforced Polyamide Illustrated on Microscopic Scale, J. Appl. Polym. Sci., 131(19), 40842(1-14).
  6. Cahn, R.W., Haasen, P., Kramer, E.J. (1996) Materials Science and Technology: Plastic Deformation and Fracture of Aaterials: A Comprehensive Treatment Volume 6, Wiley-VCH Weinheim, p.710.
  7. De Monte, M., Moosbrugger, E. (2010), Influence of Temperature and Thickness on the Off-Axis behaviour of Short Glass Fibre Reinforced Polyamide 6.6-Quasi-static Loading, Compos. Part A: Appl. Sci. & Manuf., 41(7), pp.859-871.
  8. Digimat (2018) User's Manual, Ex-stream Engineering.
  9. Doghri, I., Ouaar, A. (2003) Homogenization of Two-Phase Elasto-Plastic Composite Materials and Structures-Study of Tangent Operators, Cyclic Plasticity and Numerical Algorithms, Int. J. Solids Struct., 40, pp.1681-1712.
  10. Eshelby, J. (1957) The Determination of the Elastic Field of an Ellipsoidal Inclusion and Related Problems, Proc. Roy. Soc. London Ser. A, 241, pp.376-396.
  11. FEMFAT 4.7 (2007) Theory Manual. St. Valentin.
  12. Gaier, C., Dannbauer, H., Werkhausen, A. (2007) Fatigue Life Prediction of Short Fiber Reinforced Plastic Components, NAFEMS Seminar Simulating Composite Materials and Structures.
  13. Grove, D., Kim, H. (1995) Fatigue Behavior of Long and Short Glass Reinforced Thermoplastics, J. Mater. & Manuf., 104(5), pp.450-456.
  14. Kammouna, S., Doghri, I., Adam, L., Robert, G., Delannay, L. (2011) First Pseudo-Grain Failure Model for Inelastic Composites with Misaligned Short Fibers, Compos.: Part A, 42, pp.1892-1902.
  15. Kammouna, S., Doghri, I., Adam, L., Robert, G., Delannay, L. (2015) Micromechanical Modeling of the Progressive Failure in Short Glass-Fiber Reinforced Thermoplastics-First Pseudo-Grain Damage Model, Compos.: Part A, 73, pp.166-175.
  16. Krairi, A., Doghri, I., Robert, G. (2016) Multiscale High Cycle Fatigue Models for Neat and Short Fiber Reinforced Thermoplastic Polymers, Int. J. Fatigue, 92, pp.179-192.
  17. Kujawski, D., Teo, J.L.K. (2017) A Generalization of Neuber's Rule for Numerical Applications, 2nd Int. Conf. Struct. Integr.
  18. Lavengood, R.E., Gulbransen, L. (1969) The Effect of Aspect Ratio on the Fatigue Life of Short Boron Fiber Reinforced Composites, Polym. Eng. Sci., 9, pp.365-369.
  19. Linn, J. (2005) The Folgar-Tucker Model as a Differential Algebraic System for Fiber Orientation Calculation, ITWM, 75, pp.2-4.
  20. Marohni, T., Basanb, R., Franulovic, M. (2015) Evaluation of the Possibility of Estimating Cyclic Stress-Strain Parameters and Curves from Monotonic Properties of Steels, Pro. Eng., 101, pp.277-284.
  21. Mallick, P.K. (1993) Fiber-Reinforced Composites: Materials, Manufacturing and Design 3rd Edition, CRC Press, Florida, p.638.
  22. Miner, M.A. (1945) Cumulative Damage in Fatigue. J. Appl. Mech-Trans. ASME, 12(3), A159-64.
  23. Mori, T., Tanaka, K. (1973) Average Stress in Matrix and Average Elastic Energy of Materials with Misfitting Inclusions, Acta. Metall., 21(5), pp.571-574.
  24. Mortazavian, S., Fatemi, A. (2015) Fatigue Behavior and Modeling of Short Fiber Reinforced Polymer Composites Including Anisotropy and Temperature Effects, Int. J. Fatigue, 77, pp.12-27.
  25. Park, J.M., Kim, H.D. (2015) Properties of Randomly Oriented Chopped E-glass Reinforced Unsaturated Polyester based Resin Composite, Korean Soc. Dyers. & Finish., 9, pp. 165-174.
  26. Ramberg, W., Osgood, W. (1943) Description of Stress-Strain Curves by Three Parameters, Technical Note No. 902.
  27. Rolland, H., Saintier, N., Gobert, G. (2016) Fatigue Mechanisms Description in Short Glass Fibre Reinforced Thermoplastic by Microtomographic Observations, Proc. Struct. Integr., 2, pp.301-308.