Experimental characterization of the compaction behavior in preforming process for 3D stitched carbon fabric

The compaction behavior of the 3D stitched fabric, which significantly affects the mechanical performance of the 3D stitched composites, has not been explored yet. Herein, the systematical compaction experiments were originally conducted to explore the influence of the stitching pattern and space on the compaction behavior of 3D stitched carbon fabric. The results reveal that the reduction of stitching space enhances the compression resistance, as the stitching thread restricts the yarn flattening and slippage. The diagonal stitched fabric presents the high compression resistance due to its relative uniformly distributed constraining forces acted on both warp and weft yarns. It is originally identified that the internal stress in the diagonal stitched fabric is more difficult to dissipate, since the stitching thread restricts the fibers movement. Besides, the diagonal stitched fabric with dense stitching space presents high permanent recovery ratio, suggesting that the near net shape perform can be more flexibly obtained.