journal article·2025-08Open access

Numerical Methodology Development and Validation for Fatigue Life Prediction of PA-6 Long Fibre Thermoplastic Material Manufactured Using Compression Moulding

Sharath Christy Anand, Xiangfan Fang

Applied Composite Materials· Volume 32· Issue 4

Abstract

Abstract This paper presents a numerical methodology developed for the modelling of fatigue life of PA6 long fibre thermoplastic (LFT) material with 40% glass fibre content (PA6-LFT40) produced using compression moulding for the incorporation of long fibre, which enhances the mechanical properties compared to injection-moulding. Firstly, compression moulding process simulations were performed to predict fibre orientation using Autodesk Moldflow. Model parameters for process simulation were calibrated until the predicted fibre orientation matched the orientations obtained using micro X ray-Computer Tomography on PA6-LFT40 plates. The calibrated fibre orientations were then mapped to a finite element method (FEM) solver mesh to perform standard static three point bending test. Tensile tests served as the corresponding material model inputs for the simulations. Using mapped FEM simulation, the deviation between simulation and tests were less than 10% that is much better than without mapping. Finally, using the experimentally determined Haigh diagram, three point bending fatigue testing of PA6-LFT40 at different load levels at a stress ratio of R = -1 were performed and evaluated by using FEMFAT. The predicted fatigue life at different load level showed good correlation with test results. In conclusion, the developed numerical methodology, enhances the predictive modelling of fatigue life of compression moulded LFT Composites.
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Research context

OpenAlex topics: Mechanical Behavior of Composites · Epoxy Resin Curing Processes · Composite Material Mechanics

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References (42)

Show source-provided references
1. Choi, J., Lee, H., Lee, H., Kim, N.: A methodology to predict the fatigue life under multi-axial loading of carbon fiber-reinforced polymer composites considering anisotropic mechanical behavior. Materials. 16, 1952 (2023). https://doi.org/10.3390/ma1605195210.3390/ma16051952 ↗
2. Kim, J.H., Song, B.K., Min, K.J., Choi, J.C., Eun, H.S.: Optimizing heat treatment conditions for measuring CFRP and GFRP resin impregnation. Materials. 15, 8182 (2022). https://doi.org/10.3390/ma1522818210.3390/ma15228182 ↗
3. Kim, J.-H., Jung, Y.-H., Lambiase, F., Moon, Y.-H., Ko, D.-C.: Novel Approach toward the forming process of CFRP reinforcement with a hot stamped part by prepreg compression molding. Materials. 15, 4743 (2022). https://doi.org/10.3390/ma1514474310.3390/ma15144743 ↗
4. Russo, A., Sellitto, A., Curatolo, P., Acanfora, V., Saputo, S., Riccio, A.: A robust numerical methodology for fatigue damage evolution simulation in composites. Materials. 14, 3348 (2021). https://doi.org/10.3390/ma1412334810.3390/ma14123348 ↗
5. Kim, J.-W., Lee, D.-G.: Study on the fiber orientation during compression molding of reinforced thermoplastic composites. Int. J. Precis. Eng. Manuf.-Green Tech. 1, 335–339 (2014). https://doi.org/10.1007/s40684-014-0042-z10.1007/s40684-014-0042-z ↗
6. Rezaei, F., Yunus, R., Ibrahim, N.A.: Effect of fiber length on thermomechanical properties of short carbon fiber reinforced polypropylene composites. Mater. Des. 30, 260–263 (2009). https://doi.org/10.1016/j.matdes.2008.05.00510.1016/j.matdes.2008.05.005 ↗
7. Bernasconi, A., Davoli, P., Basile, A., Filippi, A.: Effect of fibre orientation on the fatigue behaviour of a short glass fibre reinforced polyamide-6. Int. J. Fatigue. 29, 199–208 (2007). https://doi.org/10.1016/j.ijfatigue.2006.04.00110.1016/j.ijfatigue.2006.04.001 ↗
8. Thomason, J.L.: The influence of fibre length and concentration on the properties of glass fibre reinforced polypropylene: 5. Injection moulded long and short fibre PP. Compos. Part A: Appl. Sci. Manuf. 33, 1641–1652 (2002). https://doi.org/10.1016/S1359-835X(02)00179-310.1016/S1359-835X(02)00179-3 ↗
9. Thomason, J.L.: The influence of fibre length and concentration on the properties of glass fibre reinforced polypropylene: 7. Interface strength and fibre strain in injection moulded long fibre PP at high fibre content. Comp. Part A: Appl. Sci. Manuf. 38, 210–216 (2007). https://doi.org/10.1016/j.compositesa.2006.01.00710.1016/j.compositesa.2006.01.007 ↗
10. Willems, F., Reitinger, P., Bonten, C.: Calibration of fiber orientation simulations for LFT—A new approach. J. Compos. Sci. 4, 163 (2020). https://doi.org/10.3390/jcs404016310.3390/jcs4040163 ↗
11. Shirinbayan, M., Rezaei-khamseh, M., Nikooharf, M.H., Tcharkhtchi, A., Fitoussi, J.: Multi-scale analysis of mechanical properties and damage behavior of polypropylene composite (GF50-PP) plate at room and cryogenic temperatures. Compos. Struct. 278, 114713 (2021). https://doi.org/10.1016/j.compstruct.2021.11471310.1016/j.compstruct.2021.114713 ↗
12. Fang, X., Kloska, T.: Hybrid forming of sheet metals with long fiber-reinforced thermoplastics (LFT) by a combined deep drawing and compression molding process. Int. J. Mater. Form. 13, 561–575 (2020). https://doi.org/10.1007/s12289-019-01493-410.1007/s12289-019-01493-4 ↗
13. Gandhi, U., Sebastian, D.B., Kunc, V., Song, Y.: Method to measure orientation of discontinuous fiber embedded in the polymer matrix from computerized tomography scan data. J. Thermoplast. Compos. Mater. 29, 1696–1709 (2016). https://doi.org/10.1177/089270571558441110.1177/0892705715584411 ↗
14. Park, C.H., Lee, W.I., Yoo, Y.E., Kim, E.G.: A study on fiber orientation in the compression molding of fiber reinforced polymer composite material. J. Mater. Process. Technol. 111, 233–239 (2001). https://doi.org/10.1016/S0924-0136(01)00523-410.1016/S0924-0136(01)00523-4 ↗
15. Kanters, M.J.W., Douven, L.F.A., Savoyat, P.: Fatigue life prediction of injection moulded short glass fiber reinforced plastics. Procedia Struct. Integr. 19, 698–710 (2019). https://doi.org/10.1016/j.prostr.2019.12.07610.1016/j.prostr.2019.12.076 ↗
16. Magino, N., Köbler, J., Andrä, H., Welschinger, F., Müller, R., Schneider, M.: A space-time upscaling technique for modeling high-cycle fatigue-damage of short-fiber reinforced composites. Compos. Sci. Technol. 222, 109340 (2022). https://doi.org/10.1016/j.compscitech.2022.10934010.1016/j.compscitech.2022.109340 ↗
17. Song, Y., Gandhi, U., Sekito, T., Vaidya, U., Hsu, J., Yang, A., Osswald, T.: A novel CAE method for compression molding simulation of carbon fiber-reinforced thermoplastic composite sheet materials. J. Compos. Sci. 2, 33 (2018). https://doi.org/10.3390/jcs202003310.3390/jcs2020033 ↗
18. Sepehr, M., Ausias, G., Carreau, P.J.: Rheological properties of short fiber filled polypropylene in transient shear flow. J. Nonnewton. Fluid Mech. 123, 19–32 (2004). https://doi.org/10.1016/j.jnnfm.2004.06.00510.1016/j.jnnfm.2004.06.005 ↗
19. Wang, J., O’Gara, J.F., Tucker, C.L.: An objective model for slow orientation kinetics in concentrated fiber suspensions: Theory and rheological evidence. J. Rheol. 52, 1179–1200 (2008). https://doi.org/10.1122/1.294643710.1122/1.2946437 ↗
20. Wang, J., Jin, X.: Comparison of recent fiber orientation models in autodesk moldflow insight simulations with measured fiber orientation data. In: Proceedings of the Polymer Processing Society 26th Annual Meeting, Banff, AB, 4–8 July 2010
21. Phelps, J.H., Tucker, C.L.: An anisotropic rotary diffusion model for fiber orientation in short- and long-fiber thermoplastics. J. Nonnewton. Fluid Mech. 156, 165–176 (2009). https://doi.org/10.1016/j.jnnfm.2008.08.00210.1016/j.jnnfm.2008.08.002 ↗
22. Song, Y., Gandhi, U., Pérez, C., Osswald, T., Vallury, S., Yang, A.: Method to account for the fiber orientation of the initial charge on the fiber orientation of finished part in compression molding simulation. Compos. A Appl. Sci. Manuf. 100, 244–254 (2017). https://doi.org/10.1016/j.compositesa.2017.05.02110.1016/j.compositesa.2017.05.021 ↗
23. Converse: Plastics simulation - Documentation V4.7, Part Engineering GmbH
24. Meneghetti, G., Ricotta, M., Lucchetta, G., Carmignato, S.: An hysteresis energy-based synthesis of fully reversed axial fatigue behaviour of different polypropylene composites. Compos. B Eng. 65, 17–25 (2014). https://doi.org/10.1016/j.compositesb.2014.01.02710.1016/j.compositesb.2014.01.027 ↗
25. Mortazavian, S., Fatemi, A.: Fatigue of short fiber thermoplastic composites: A review of recent experimental results and analysis. Int. J. Fatigue 102, 171–183 (2017). https://doi.org/10.1016/j.ijfatigue.2017.01.03710.1016/j.ijfatigue.2017.01.037 ↗
26. Tanaka, K., Kitano, T., Egami, N.: Effect of fiber orientation on fatigue crack propagation in short-fiber reinforced plastics. Eng. Fract. Mech. 123, 44–58 (2014). https://doi.org/10.1016/j.engfracmech.2014.03.01910.1016/j.engfracmech.2014.03.019 ↗
27. Goel, A., Chawla, K.K., Vaidya, U.K., Chawla, N., Koopman, M.: Characterization of fatigue behavior of long fiber reinforced thermoplastic (LFT) composites. Mater. Charact. 60, 537–544 (2009). https://doi.org/10.1016/j.matchar.2008.12.02010.1016/j.matchar.2008.12.020 ↗
28. Tiemann, J.-M., Mola, J., Land, P., Krumpholz, T., Krupp, U.: Quasi static and fatigue properties of long carbon fiber reinforced polyamide. J. Mater. Eng. Perform. 31, 94–104 (2022). https://doi.org/10.1007/s11665-021-06182-510.1007/s11665-021-06182-5 ↗
29. Shirinbayan, M., Nouira, S., Imaddahen, M.-A., Fitoussi, J.: Microstructure-sensitive investigation on the plastic deformation and damage initiation of fiber-reinforced polypropylene composite. Compos. Part B: Eng. 286, 111790 (2024). https://doi.org/10.1016/j.compositesb.2024.11179010.1016/j.compositesb.2024.111790 ↗
30. Fitoussi, J., Nikooharf, M.H., Kallel, A., Shirinbayan, M.: Mechanical properties and damage behavior of polypropylene composite (GF50-PP) plate fabricated by thermocompression process under high strain rate loading at room and cryogenic temperatures. Appl. Compos. Mater. 29, 1959–1979 (2022). https://doi.org/10.1007/s10443-022-10047-y10.1007/s10443-022-10047-y ↗
31. Puck, A.: Failure analysis of frp laminates by means of physically based phenomenological models. Compos. Sci. Technol. 58, 1045–1067 (1998). https://doi.org/10.1016/S0266-3538(96)00140-610.1016/S0266-3538(96)00140-6 ↗
32. Koch, I., Zscheyge, M., Tittmann, K., Gude, M.: Numerical fatigue analysis of CFRP components. Compos. Struct. 168, 392–401 (2017). https://doi.org/10.1016/j.compstruct.2017.02.05010.1016/j.compstruct.2017.02.050 ↗
33. Brunbauer, J., Gaier, C., Pinter, G.: Computational fatigue life prediction of continuously fibre reinforced multiaxial composites. Compos. Part B: Eng. 80, 269–277 (2015). https://doi.org/10.1016/j.compositesb.2015.06.00210.1016/j.compositesb.2015.06.002 ↗
34. Carpinteri, A., Spagnoli, A., Ronchei, C., Scorza, D., Vantadori, S.: Critical plane criterion for fatigue life calculation: Time and frequency domain formulations. Procedia Eng. 101, 518–523 (2015). https://doi.org/10.1016/j.proeng.2015.02.06210.1016/j.proeng.2015.02.062 ↗
35. Eichlseder, W.: Fatigue analysis by local stress concept based on finite element results. Comput. Struct. 80, 2109–2113 (2002). https://doi.org/10.1016/S0045-7949(02)00273-010.1016/S0045-7949(02)00273-0 ↗
36. Chao, X., Qi, L., Ma, W., Ge, J., Tian, W.: Monte carlo based strategy to simulate the microstructure evolution of the short-fiber reinforced metal matrix composites. Mater. Today Commun. 33, 104275 (2022). https://doi.org/10.1016/j.mtcomm.2022.10427510.1016/j.mtcomm.2022.104275 ↗
37. Breuer, K., Spickenheuer, A., Stommel, M.: Statistical analysis of mechanical stressing in short fiber reinforced composites by means of statistical and representative volume elements. Fibers 9, 32 (2021). https://doi.org/10.3390/fib905003210.3390/fib9050032 ↗
38. Witzgall, C., Wartzack, S.: Fatigue damage of short fibre-reinforced thermoplastics in crashworthiness simulation. Appl. Mech. 4, 1188–1205 (2023). https://doi.org/10.3390/applmech404006110.3390/applmech4040061 ↗
39. Advani, S.G., Tucker, C.L.: The use of tensors to describe and predict fiber orientation in short fiber composites. J. Rheol. 31, 751–784 (1987). https://doi.org/10.1122/1.54994510.1122/1.549945 ↗
40. Nikooharf, M.H., Rezaei-Khamseh, M., Shirinbayan, M., Fitoussi, J., Tcharkhtchi, A.: Comparison of the physicochemical, rheological, and mechanical properties of core and surface of polypropylene composite (GF50-PP) plate fabricated by thermocompression process. Polym. Compos. 42, 3293–3306 (2021). https://doi.org/10.1002/pc.2605910.1002/pc.26059 ↗
41. Sevenois, R.D.B., Van Paepegem, W.: Fatigue testing for polymer matrix composites. In: Creep and fatigue in polymer matrix composites. pp. 403–437. Elsevier (2019). https://doi.org/10.1016/B978-0-08-102601-4.00013-810.1016/B978-0-08-102601-4.00013-8 ↗
42. Quaresimin, M., Ricotta, M.: Damage evolution in woven composite laminates under fatigue loading. ECCM-10: Composites for the Future: 10th European Conference on Composite Materials, Belgium, 3-7 June 2002