Title: Fiber Tow Deformations During Layup of Steered Paths Using Automated Fiber Placement Process
Authors: Roudy Wehbe, Brian Tatting, Zafer Gürdal, and Ramy Harik
Abstract: Automated Fiber Placement (AFP) is a manufacturing process used to fabricate composite structures for aerospace applications. For simple conventional laminated plate structures manufactured using the AFP process, fibers are laid at constant angles (0°, 90°, ±45°) in straight paths. However, to manufacture complex shell structures or variable stiffness plates, the straight fiber tows must deform to adhere to the curved paths. In this paper, those deformations are classified as strain deformations (tensile, compressive, shear), large in-plane deformations (waviness and bunching), and out-of-plane deformations (wrinkling and folding). The aim of this paper is to understand which of these deformation mechanisms is predominant during the manufacturing process. To do so, the carbon fiber tow is modeled as multiple fiber bundles placed on a stiff elastic foundation within a constrained curved path. The governing nonlinear differential equations are derived based on minimizing the total energy of the system, and the final shape of the deformed tow is obtained by solving the system numerically. Mainly, compressive strains, fiber waviness, and/or wrinkling are the main deformation modes on the compressive side of the tow, whereas tensile strain, fiber bunching, and/or tow folding occur on the tensile side. The importance of the material properties, radius of curvature, stiffness of the foundation and other process parameters on the final shape of the deformed tow is also discussed.
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Conference: SAMPE 2019 - Charlotte, NC
Publication Date: 2019/05/20
Price: FREEGet This Paper