Investigation on the mechanical properties and ballistic behaviors of sandwich structure of <scp>CFRP</scp> and biomimetic tendon plates with aramid filaments bundle

Abstract Textile fiber composite materials are widely used in bulletproof applications due to their lightweight and strong impact resistance. Composite materials made from aramid usually use fabrics and filaments as enhancement, but no composite materials made from filament bundles have been seen. The structures of animals and plants in nature have undergone long‐term evolution and possess excellent mechanical properties. Tendons are a tough connective tissue composed of a large number of parallel fibers arranged to form a tough structure. Inspired by the nature structure of tendon, a multi‐stage winding structure of biomimetic tendon plate with aramid filaments bundle (BTAF) was proposed. In this structure, the filament bundle assembly is tightly wound, and collectively subjected to the impact. However, the stress is easily concentrated, and the average specific energy absorption (SEA) is only 1.40 J/g. In order to distribute the bullet impact to more filament bundles, CFRP were added to the upper and lower surfaces of the filament bundle plate to form a sandwich structure C‐BTAF. The experimental results show that this C‐BTAF presents higher SEA, with an increase of 52.86% compared to BTAF plate. Highlights A sandwich structure of C‐BTAF is made by winding method. The compression stress and bending stress of primary hierarchy is higher. The specific energy absorption of C‐BTAF more than that of BTAF plate. The sandwich structure of C‐BTAF plate has better energy dispersion ability. The back CFRP mainly plays a supporting role to the BTAF.