COMPARATIVE STUDY OF 3-DIMENSIONAL WOVEN JOINT ARCHITECTURES FOR COMPOSITE SPACECRAFT STRUCTURES

摘要

The National Aeronautics and Space Administration (NASA) Exploration Systems MissionDirectorate initiated an Advanced Composite Technology (ACT) Project through the ExplorationTechnology Development Program in order to support the polymer composite needs for futureheavy lift launch architectures. As an example, the large composite structural applications onAres V inspired the evaluation of advanced joining technologies, specifically 3D wovencomposite joints, which could be applied to segmented barrel structures needed for autoclavecured barrel segments due to autoclave size constraints. Implementation of these 3D wovenjoint technologies may offer enhancements in damage tolerance without sacrificing weight.However, baseline mechanical performance data is needed to properly analyze the joint stressesand subsequently design/down-select a preform architecture. Six different configurations weredesigned and prepared for this study; each consisting of a different combination of warp/fill fibervolume ratio and preform interlocking method (Z-fiber, fully interlocked, or hybrid). Tensiletesting was performed for this study with the enhancement of a dual camera Digital ImageCorrelation (DIC) system which provides the capability to measure full-field strains and threedimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has adirect influence on strength and modulus, with higher values measured in the direction of higherfiber volume bias. When comparing the Z-fiber weave to a fully interlocked weave withcomparable fiber bias, the Z-fiber weave demonstrated the best performance in two differentcomparisons. We report the measured tensile strengths and moduli for test coupons from the 6different weave configurations under study.0