Design domain where the black lines are notional fiber paths and the contour indicates the unnormalized spatially varying fiber volume fraction. The inset square is a sampling of the design space that is mapped into the structural analysis of a composite flat plate.
Fiber-reinforced composites (FRCs) are widely used in aerospace and other high-performance applications due to their high strength-to-weight ratio. Traditional composite design assumes straight, uniformly aligned fibers within each ply, with optimization focused on selecting ply orientations. While effective for many structures, this approach becomes limiting for morphing systems that must undergo complex, multi-directional deformations.
To address this challenge, our research explores composites reinforced with curvilinear (tow-steered) fibers, which enable spatial tailoring of material behavior. Tow steering significantly expands the design space by allowing fiber orientations to vary continuously, improving the ability to manage stress distributions and accommodate non-zero Gaussian curvature deformations.
We develop computational methods to model and design these materials using parameterized vector fields. From a governing vector field, both the local fiber orientation and fiber volume fraction are derived, enabling a fully spatially varying representation of composite properties. This framework supports efficient exploration of manufacturable tow-steered designs and their structural performance.
This ongoing work focuses on applying these tools to morphing aerospace structures, including components with intrinsically curved geometries.
Related Publication: Lilly, J. and Hartl, D., 2025. Development of a Tow-steered Composite Design Tool for Morphing Applications. XI ECCOMAS Thematic Conference on Smart Structures and Materials.
Graduate Student: Jared Lilly