Integrated Design and Analysis Tools for Reduced Weight, Affordable Fiber Steered Composites

摘要

This report describes geometric design tools which encompass the overall process flow for fiber placed and fiber steered structures, to allow parallel considerations for manufacturability and mechanical performance. Several methods for modeling individual tows in a fiber placed part are defined and verified. Analytical methodologies for fiber steering are demonstrated on four test models and three representative aircraft components. Weight savings of up to 30% are attainable for singularly loaded examples. Rangewise continuous layer-angle and layer-thickness contours are demonstrated, with layer thickness and fiber orientation being load-path sensitive. Weight savings on the order of 7% are demonstrated on more realistic examples. Mechanical testing illustrates that fiber steered components follow predictable trends. In particular, data demonstrates no statistically significant variation in compression stiffness or compression strength to steering radii of 46cm. Destructive and nondestructive evaluation experiments reveal higher density occurrences of tow and course edge features, such as overlaps, twists, gaps and fiber waviness.