Title: Triaixial Overbraiding of Complex Composite Structures Using Melt-out Mandrels

Authors: Waruna Seneviratne, Josh Goertz

DOI: 10.33599/nasampe/s.25.0183

Abstract: A serpentine inlet duct for a 30-foot unmanned combat aircraft was designed as part of the Air Force Research Lab (AFRL)-funded Manufacturing for Affordable Sustainable Composites (MASC) program at Wichita State University (WSU). This manufacturing demonstrator aimed to develop a cost model based on manufacturing data, including various materials, processes, and assembly methods. The goal was to enable the industry to leverage this information for ondemand, flexible manufacturing and assembly of composite structures tailored to specific volume, cost, weight, and mission requirements. The inlet duct’s complex curvature necessitated a novel manufacturing approach. Automated tape-laying for tow placement was constrained by the part's minimum radius of curvature, and hand placement of prepreg would have led to excessive cutting and splicing. To address this challenge, the overbraiding technology developed by A&P Technology in Cincinnati, Ohio was employed to demonstrate high-rate production for this aircraft component. The demonstrator inlet duct measures approximately eight feet in length, with perimeters ranging from 56.5 to 96.6 inches. The melt-out mandrel for the tool was created using Fiber Dynamics' Lost Core Tooling System. A&P Technology then used this system to overbraid five layers of triaxial braid at a constant thickness, achieving bias angle changes along the part's length from ±55° to ±71°. The process was executed without any cuts or splices, and the precise control of fiber angles ensured consistently high part-to-part repeatability. These research findings will provide valuable insights for the design, manufacturing, and certification of over-braided structures for complex geometries.

References: [1] L. C. Dorworth, G. L. Gardiner, and G. M. Mellema, Essentials of advanced composite fabrication and repair. Newcastle, Wash: Aviation Supplies & Academic, 2009. [2] M. Salzmann, M. Teuchtmann, and R. Schledjewski, “Determination of the glass transition temperature of an epoxy prepreg by Near Infrared Spectroscopy,” Polymer Testing, vol. 125, p. 108111, Aug. 2023, doi: 10.1016/j.polymertesting.2023.108111. [3] U. Yilmazoglu and R. Hanzlik, “Troubleshooting Common Prepreg Cure Failure Modes with Rheological Measurements,” presented at the SAMPE 2024, The Society for the Advancement of Material and Process Engineering (SAMPE), May 2024. doi: 10.33599/nasampe/s.24.0105. [4] C. W. Macosko, Rheology: principles, measurements, and applications. in Advances in interfacial engineering series. New York, NY: VCH, 1994. [5] K. P. Menard, Dynamic Mechanical Analysis: A Practical Introduction, Second Edition, 2nd ed. Boca Raton: CRC Press, 2008. doi: 10.1201/9781420053135. [6] B. Wunderlich, Ed., “Basics of Thermal Analysis,” in Thermal Analysis of Polymeric Materials, Berlin, Heidelberg: Springer, 2005, pp. 71–188. doi: 10.1007/3-540-26360-8_2. [7] M. L. Costa, M. C. Rezende, J. M. F. De Paiva, and E. C. Botelho, “Structural Carbon/Epoxy Prepregs Properties Comparison by Thermal and Rheological Analyses,” Polymer-Plastics Technology and Engineering, vol. 45, no. 10, pp. 1143–1153, Oct. 2006, doi: 10.1080/03602550600887251. [8] L. Pilato and M. J. Michno, Advanced composite materials. Berlin: New York : SpringerVerlag, 1994. doi: 10.1007/978-3-662-35356-1. [9] Gurit, “Guide to Composites.” Accessed: Mar. 07, 2025. [Online]. Available: https://www.gurit.com/wp-content/uploads/2022/12/guide-to-composites-1.pdf [10] G. W. Ehrenstein, G. Riedel, and P. Trawiel, “Dynamic Mechanical Analysis (DMA),” in Thermal Analysis of Plastics, Carl Hanser Verlag GmbH & Co. KG, 2004, pp. 236–299. doi: 10.3139/9783446434141.006. [11] M. M. Bertotto, A. Gastón, M. J. Rodríguez Batiller, and P. Calello, “Comparison of mathematical models to predict glass transition temperature of rice (cultivar IRGA 424) measured by dynamic mechanical analysis,” Food Science & Nutrition, vol. 6, no. 8, pp. 21992209, 2018, doi: 10.1002/fsn3.785. [12] H. Pawlowski, L. Dorworth, and R. Hanzlik, “Optimization of Cure Cycles Using an ESR (Encapsulated Sample Rheometer),” Jan. 2020. doi: 10.33599/s.20.0171. [13] J.-P. Pascault, H. Sautereau, J. Verdu, and R. J. J. Williams, Thermosetting Polymers. Boca Raton: CRC Press, 2002. doi: 10.1201/9780203908402. [14] G. Van Assche, A. Van Hemelrijck, H. Rahier, and B. Van Mele, “Modulated temperature differential scanning calorimetry: Cure, vitrification, and devitrification of thermosetting systems,” Thermochimica Acta, vol. 304, pp. 317–334, Jan. 1997, doi: 10.1016/S0040-6031(97)00175-5. [15] Y. Jahani, M. Baena, C. Barris, R. Perera, and L. Torres, “Influence of curing, postcuring and testing temperatures on mechanical properties of a structural adhesive,” Construction and Building Materials, vol. 324, p. 126698, Mar. 2022, doi: 10.1016/j.conbuildmat.2022.126698. [16] R. Carbas, E. Marques, L. F. M. Silva, and A. Lopes, “Effect of Cure Temperature on the Glass Transition Temperature and Mechanical Properties of Epoxy Adhesives,” Journal of Adhesion, vol. 90, Jan. 2014, doi: 10.1080/00218464.2013.779559. [17] O. Ruíz de Azúa, N. Agulló, J. Arbusà, and S. Borrós, “Improving Glass Transition Temperature and Toughness of Epoxy Adhesives by a Complex Room-Temperature Curing System by Changing the Stoichiometry,” Polymers (Basel), vol. 15, no. 2, p. 252, Jan. 2023, doi: 10.3390/polym15020252. [18] A. Soahib, Zhe Miao, and Y. Irfan, “Analysis of Cure Reaction Kinetics of Aramid/Toughened-Epoxy Prepreg System Aiming at Processing of Composite Material for Structural Applications,” Journal of Polymer Engineering, vol. 27, no. 8, pp. 565–582, Dec. 2007, doi: 10.1515/POLYENG.2007.27.8.565. [19] M. L. Costa, M. C. Rezende, and S. F. M. De Almeida, “Effect of Void Content on the Moisture Absorption in Polymeric Composites,” Polymer-Plastics Technology and Engineering, vol. 45, no. 6, pp. 691–698, Jul. 2006, doi: 10.1080/03602550600609549. [20] D. J. Plazek and Z. N. Frund Jr., “Epoxy resins (DGEBA): The curing and physical aging process,” Journal of Polymer Science Part B: Polymer Physics, vol. 28, no. 4, pp. 431–448, 1990, doi: 10.1002/polb.1990.090280401. [21] G. Fernlund et al., “Experimental and numerical study of the effect of cure cycle, tool surface, geometry, and lay-up on the dimensional fidelity of autoclave-processed composite parts,” Composites Part A: Applied Science and Manufacturing, vol. 33, no. 3, pp. 341–351, Mar. 2002, doi: 10.1016/S1359-835X(01)00123-3. [22] E. S.-W. Kong, “Physical aging in epoxy matrices and composites,” in Epoxy Resins and Composites IV, K. Dušek, Ed., Berlin, Heidelberg: Springer, 1986, pp. 125–171. doi: 10.1007/3540-16423-5_14.

Conference: SAMPE 2025

Publication Date: 2025/05/19

SKU: TP25-0000000183

Pages: 12

Price: $24.00