Title: A Comparative Study on the Viscoelastic Bending Stiffness of Various Uncured Carbon Fiber Prepreg Materials

Authors: Roudy Wehbe, Breanna Badger, Damon Call

DOI:

Abstract: One of the key physical characteristics of uncured thermoset prepreg during automated layup and forming applications is its drapability, or its ability to bend and conform on curved surfaces. These layups or forming operations occur at various temperatures and speeds, therefore it is necessary to investigate the viscoelastic bending behavior of uncured prepreg under these conditions in order to simulate the manufacturing process and mitigate potential defect formation. In this study, the creep response of various prepreg architectures is analyzed in 3point bend loading using a thermomechanical analyzer (TMA). The short-term creep tests are conducted at various isothermal holds ranging from 15°C to 40°C and for 1000 seconds. The unidirectional prepregs tested include different types of fibers, resins, and thicknesses. Timetemperature superposition principle is used to construct creep compliance master curves at relevant reference temperatures to compare the different materials and to determine the bending behavior at the relevant loading rates/speeds during manufacturing process. Results show that this method is capable of detecting differences in prepreg constituents and their impact on the bending behavior at various temperatures and speeds during the manufacturing processes.

References: 1. Wang,Y., Mahapatra, S., Belnoue, J., Ivanov, D., & Hallett, S., "Modelling the effect of process conditions on steering-induced defects in automated fibre placement (AFP)." Composites Part A: Applied Science and Manufacturing 173 (2023): 107702 https://doi.org/10.1016/j.compositesa.2023.107702 2. Brasington, A., Sacco, C., Halbritter, J., Wehbe, R., & Harik, R. "Automated fiber placement: A review of history, current technologies, and future paths forward." Composites Part C: Open Access 6 (2021): 100182. https://doi.org/10.1016/j.jcomc.2021.100182 3. Crossley, R. J., Schubel, P. J., & Warrior, N. A., “The Experimental Determination of Prepreg Tack and Dynamic Stiffness,” Composites Part A: Applied Science and Manufacturing 43 (2012):423-434. https://doi.org/10.1016/j.compositesa.2011.10.014 4. Alshahrani, H., & Hojjati, M., “A new Test method for the characterization for the bending behavior of textile prepregs.” Composites Part A: Applied Science and Manufacturing 97 (2017): 128-140. https://doi.org/10.1016/j.compositesa.2017.02.027 5. Samuel Erland, “Characterisation of Uncured Carbon Fibre Prepreg.” University of Bath (2017). 6. Margossian, A., Bel, S., & Hinterhoelzl, R., "Bending characterisation of a molten unidirectional carbon fibre reinforced thermoplastic composite using a Dynamic Mechanical Analysis system." Composites Part A: Applied Science and Manufacturing 77 (2015): 154163. https://doi.org/10.1016/j.compositesa.2015.06.015 7. Rajan, S., Sutton, M. A., Wehbe, R., Gurdal, Z., Kidane, A., & Emri, I. "Characterization of viscoelastic bending stiffness of uncured carbon-epoxy prepreg slit tape." Composite Structures 275 (2021): 114295. https://doi.org/10.1016/j.compstruct.2021.114295 8. “TA Instruments Thermomechanical Analyzer”, https://www.tainstruments.com/pdf/literature/TMAQ400.pdf

Conference: SAMPE 2026

Publication Date: 2026/04/27

SKU: 36

Pages: 10

Price: $20.00