Impact characteristics of needled/I-fiber coupling reinforced composite

As a widely used thermal protection material for the aerospace vehicle, needled composites cannot avoid the impact load of the external environment during flight or reentry process, but the lack of continuous reinforcing fibers in the thickness direction results in weak impact resistance. In order to improve impact resistance property, this paper proposed a new type of needled/I-fiber coupling reinforced composite structure and carried out impact characteristics research. First, the needled/I-fiber coupling reinforced preforms and composites with different I-fiber stitching parameters were prepared; further, the impact tests of needled/I-fiber coupling reinforced composites were carried out, and the damage area and bulge height after impact were measured. Finally, the compressive strengths after impact were tested and analyzed. The research results showed that I-fiber absorbed the impact energy and effectively inhibited the delamination propagation of the needled/I-fiber coupling reinforced composite during the impact process. The damage area and bulge height of the needled/I-fiber coupling reinforced composite were reduced by up to 46.5 and 46.02% respectively. Moreover, the compression strength after impact increased by up to 17.6%. Our work may provide a simple and effective method for improving the impact resistance of needled composites structure for aerospace vehicle.