Integration of Complex Geometry, 3D Woven Preforms via Innovative Stitching Technique, Phase I

The proposed innovation is directly relevant to NASA Ames' 3D-woven carbon/phenolic thermal protection system (3D-TPS) for re-entry vehicle heat shield applications. The proposed innovation will enable the mechanical joining of thick 3D woven carbon fiber preforms (up to 3" thick), which in turn will enable multiple panels of the 3D-TPS material system to be assembled into actual re-entry vehicle geometries. Similarly, the proposed innovation will also enable joining of thinner 3D woven carbon substrates, which will allow the fabrication of the complex geometries required for NASA's deployable aeroshell application. The proposed innovation will create the capability to stitch/join together carbon fiber preform assemblies with geometries too complex for existing textile processes, including 3D weaving, to achieve. Potential commercial applications thus include those composite applications where through thickness strength AND complex geometry are both required. Examples include composite armor for military vehicles and structural composites for aerospace including stitched skin + core assemblies, stitched joint assemblies and stitched skin + web-stiffener assemblies. More »