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

Thick, 3D woven carbon/phenolic composites offer potential improvement over legacy thermal protection systems (TPS) for re-entry vehicle heat shield applications. However due to the scale and complexity of typical re-entry vehicle structures, it is likely that multiple 3D woven panels would need to laid up to create the overall heat shield, creating a potential weak spots at the panel joints. T.E.A.M., Inc. proposes to address the joint issue by developing an innovative stitching process capable of forming mechanically reinforced joints between densely woven, 3D carbon fiber pre-forms up to 3" thick. The Phase I scope will include design, model and fabrication of multiple stitched joint specimens, which will be tensile tested to characterize relative strengths of various joint configurations as a function of stitching parameters used. Results will enable calibration of the initial model as well as initial design of a scaled up process capable of producing a full scale, net-shape re-entry vehicle structure within Phase II.