Single ply 3Dwoven Functionally Gradient Multi-Fiber / Multi-Matrix Composites with Thermal Management Systems

Common screwdrivers graduate from a locally hard tip to a globally ductile shaft. Likewise, hybrid metallic molds have been produced which have conductive alloys in strategic locations leading heat to appropriate sinks. Fiber composite structures have also been made with more brittle high temperature layers and inlays. Unfortunately, lamination of disparate materials in such composites incurs weight penalties and encourages failures. Instead, we propose to weave the desired materials into different regions or surfaces of one fabric of full thickness for the part. This project will pursue the combination of a gradient polymer matrix with single ply 3D woven preforms hybridized with multiple fiber types, to provide localized thermal resistance, insulation, and planned conductivity in a single ply composite. With guidance from an aerospace integrator, composite samples relevant to known aero structure problems will be designed, exploiting the flexibility of the 3D weaving process for gradient hybridization of preforms, as well as partner UDEL-CCM's CIRTM methods for the infiltration of such fiber preforms with multiple or gradient matrices. Further, z-axis fibers will be exploited to weave in a through-panel radiator. Thermo-mechanical predictions will be compared to results of simple tests toward determining the feasibility of designing and manufacturing composite elements which have planned local thermal behaviors, minimize compromises to global properties, and which eliminate delamination altogether due to both mitigation of thermal misfits by gradient design, and by the inherently integral single ply nature of the 3D woven preforms themselves.