Title: Performance of Stretch-Steered Aligned Discontinuous Fiber Tape with Automated Fiber Placement

Authors: Aidan S. Ford, Mark Davis, Roger Crane, Dirk Heider, Thomas A. Cender

DOI: 10.33599/nasampe/s.24.0009

Abstract: Tailored steered tow paths with automated fiber placement (AFP) can offer many advantages in composite manufacturing. With AFP, the ability to place tapes on complex geometries at a high level of precision is possible. A minimum steering radius limits placement continuous fiber tape on complex paths due to compressive strain along the inner radius of a tape. This study utilizes a pulse width modulated laser assisted AFP process to in-situ stretch an epoxy matrix aligned discontinuous fiber tape. In order to properly apply strain to a thermoset tape, a temperature calibration was performed to ensure proper viscosity of the tape at the nip point of the AFP process. With a 30% applied strain. a 25.4 mm (1 in) wide tape is demonstrated to be steered without wrinkle defects at a radius of 100 mm (4 in). Steering with applied strain also introduced a strain gradient across the width of the tape, a maximum along the outside and minimum along the inside radius. The results in this work investigate the effect of applied strain on the mechanical properties. Uni-directional panels placed at various strain levels were produced for tension testing. The results of this test demonstrated a 94% retention of modulus and 85% retention in strength up to 50% strain.

References: 1. Z. Gürdal, R. Olmedo. In-plane response of laminates with spatially varying fiber orientations: variable stiffness concept. AIAA Journal 31 (4) 751–758, 1993. doi:10.2514/3.1161 2.Kim, B. C., Weaver, P. M., &Potter, K., Manufacturing characteristics of the continuous tow shearing method for manufacturing of variable angle tow composites. Composites Part A: Applied Science and Manufacturing, 61, 141–151, 2014. https://doi.org/10.1016/j.compositesa.2014.02.019 3.Tierney, J., Vanarelli, A., Heider, D., Yarlagadda, S., Gillespie, Jr., J. W., “Aligned discontinuous fiber preforms, composites and systems and processes of manufacture,” US. Patent 10,669,659 B2, June 2, 2020. 4.Füssel, L., Cender, T. A., Austermann, V., Gillespie, J. W., &Heider, D. (n.d.). Tow Steering of Stretchable TuFF Thermoplastic Tape with Laser Tape Placement. In: SAMPE 2022 – Charlotte, NC. Proceedings; 2022. 5.Legenstein, A., Fussel, L., Heider, D., Gillespie, J. W., &Cender, T. A. (n.d.). Stretch-Steering of Highly Aligned Discontinuous Fiber Tape with Automated Fiber Placement. In: SAMPE 2023 – Seattle, WA. Proceedings 2023. 6.Morris, K. S., Cender, T. A., Thostenson, E. T., &Yarlagadda, S. (n.d.). Methodology for Characterizing the Forming Limits of Highly Aligned Discontinuous Fiber Composite Laminates, In ASC 2023 – Boston, MA, Proceedings 2023.

Conference: SAMPE 2024

Publication Date: 2024/05/20

SKU: TP24-0000000009

Pages: 9

Price: $18.00