Title: Characterizing Prepreg Woven Fabrics for Formability

Authors: Eileen E. Miller, Matthew C. Rand, Joseph Coughlin, and James A. Thomas

DOI: 10.33599/nasampe/s.22.0720

Abstract: State of the art for commercial aerospace stringer-stiffened skins use 3 styles of a toughened carbon/epoxy prepreg material forms: unidirectional tape, plain weave, and a bias plain weave. Despite manufacturing improvements, wrinkles remain a challenge for complex, highly contoured structure. With future production systems increasing rates, there is a need to enable 100% automation and first pass quality. The ultimate goal is to develop a thread from material attributes through to the production system to inform material and design requirements early in development. The objective of this study is to evaluate alternative woven fabric forms for improved forming characteristics. The dominant deformation mechanisms are well known in the literature. The individual ply mechanisms, intra-ply stiffness, bending stiffness, and bulk factor, have been characterized in the uncured state for HexPly® M97/IM7-GP-6K prepregs with various weave styles. Using digital image correlation, wrinkle formation is studied, and the material response to shear and bending are correlated back to the material weave attributes. Results of this work recommend that a PrimeTex® 4H satin weave offers improved formability and reduced bulk over the state of the art materials. The results of this study support current efforts on the strain fields of stringers during forming.

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Conference: SAMPE 2022

Publication Date: 2022/05/23

SKU: TP22-0000000720

Pages: 15

Price: $30.00