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Study of Void Evolution in Epoxy Resin During Cure


Title: Study of Void Evolution in Epoxy Resin During Cure

Authors: Kaitlin Rigitano, Andy George, Dan Rapking, G.P Tandon and Thao Gibson

DOI: 10.33599/nasampe/s.20.0085

Abstract: It is well known that voids in composite materials lead to decreased structural performance. It is therefore necessary to understand their behavior in order to minimize the negative effects caused by the presence of these defects. In this work, an experiment was developed to study the evolution of voids in an epoxy material during cure. The experimental apparatus featured transparent glass tooling that allowed voids to be observed using an optical imaging setup under vacuum and elevated temperature conditions. Intentionally induced defects along with naturally evolving porosity were studied in both neat resin films and carbon fiber prepreg materials. Image analysis led to information on the evolution of void content, size, distribution, shape, and movement in an epoxy as a function of the cure cycle, and post-experiment optical microscopy provided insight into the morphology of defects that become trapped within composite materials during cure.

References: 1. Gardiner, G. “Out-of-autoclave prepregs: hype or revolution?” High Perform Compos (2011). 2. Centea, Timotei, Lessa K. Grunenfelder, and Steven R. Nutt. "A review of out-of-autoclave prepregs–Material properties, process phenomena, and manufacturing considerations." Composites Part A: Applied Science and Manufacturing 70 (2015): 132-154. 3. Ridgard, C. “Out of autoclave composite technology for aerospace, defense and space structures.” Proc SAMPE 2009 conf. Baltimore, MD, 2009. 4. Hamill, L, Centea, T., and Nutt, S. "Surface porosity during vacuum bag-only prepreg processing: Causes and mitigation strategies." Composites Part A: Applied Science and Manufacturing 75 (2015): 1-10. 5. Centea, T., and Hubert, P. "Out-of-autoclave prepreg consolidation under deficient pressure conditions." Journal of Composite Materials 48.16 (2014): 2033-2045. 6. Olivier, P., Cottu, J., and Ferret, B. "Effects of cure cycle pressure and voids on some mechanical properties of carbon/epoxy laminates." Composites 26.7 (1995): 509-515. 7. "Composite Materials Handbook," MIL-HDBK-17-3F. Department of Defense, 3(5) (2002) 8. L. Ling, B. Zhang, D. Wang and Z. Wu. "Effects of Cure Cycle on Void Content and Mechanical Properties of Composite Laminates." Composite Structures 73 (2006): 303-309. 9. Ghiorse, S. R. "Effects of Void Content on the Mechanical Properties of Carbon/Epoxy Laminates." SAMPE Quarterly 24(2) (1993): 54-59. 10. Lucas S, Howard S, Senger J. Vacuum bag only processing: improving prepreg out-time and porosity for large composite structure. Proc SAMPE 2010 conf. Seattle, WA, 2010. 11. Sutter JK, Kenner WS, Pelham L, Miller SG, Polis DL, Hou T, et al. Comparison of autoclave and out-of-autoclave composites. Proc 42nd int SAMPE tech conf. Salt Lake City, UT, 2010. 12. Helmus, R. et al. “An experimental technique to characterize interplay void formation in unidirectional prepregs.” Journal of Composite Materials 51(5) (2017): 579-591. 13. Hu, W. et al. “In situ monitoring and analysis of void evolution in unidirectional prepreg.” Journal of Composite Materials 52(21) (2018): 2847-2858. 14. Gangloff, J. et al. “Entrapment and venting of bubbles during vacuum bag prepreg processing.” Journal of Composite Materials 51(18): (2017), 2757-2768. 15. (2020) 16. Bonnet, N. “Shading correction (a posteriori).” UMRS-INSERM (Reims, France), (2020). 17. Fullwood, D., D. Gerrard, A. George, & D. Halverson. “Dispersion metrics for composites – a machine learning based analysis.” Proceedings of SAMPE International Conference, Long Beach, USA, 2013. 18. Niezgoda, S., Fullwood, D., and Kalidindi, S. “Delineation of the space of 2-point correlations in a composite material system.” Acta Mater 56 (2008): 5285–5292. 19. He, Kaiming, et al. "Mask r-cnn. corr abs/1703.06870 (2017)." arXiv preprint arXiv:1703.06870,, (2017). 20. Wu, Y. et al. “Detectron2.”, (2019).

Conference: SAMPE 2020 | Virtual Series

Publication Date: 2020/06/01

SKU: TP20-0000000085

Pages: 17

Price: FREE

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