Significantly Improve the Interlaminar and In‐Plane Properties of Needled Composite Preform by Novel Short Fiber Web Peeling Method

ABSTRACT Needled composites are widely used as structural materials and electromagnetic wave transmitting materials for aerospace vehicles. However, the load‐bearing capacity is limited by the presence of low‐density and low mechanical properties short fiber web within the material. In response to this issue, this paper introduced a novel short fiber web peeling method that significantly improved both interlaminar and in‐plane mechanical properties of needled preforms. First, the high load‐bearing needled preforms were prepared using this new method. Subsequently, structural characterization, interlaminar peeling strength testing, and in‐plane tensile performance research were conducted and compared with traditional needled preforms. The results indicated that under identical process parameters, short fiber web peeling needled preform had 1.5 times the needled fiber bundles content of the traditional preform, and the fiber volume fraction of preform increased by 54.44%–58.49%. Additionally, the interlaminar peeling property improved by 12.19%–103.25%, and the in‐plane tensile strength enhanced by 53.21%–251.87%. Furthermore, the influence of different process parameters on the performance of needled preforms was also revealed. It was found that superior comprehensive mechanical properties were obtained by using 25 mm half‐cut width, an areal density of short fiber web of 50 g/m ² , needling density with 15 needles/cm ² , and half‐cut short fiber web structure.