Abstract: 3D fabric composites exhibit promising application potential in the field of impact-resistant aerospace structures. This study conducted over 30 ballistic impact tests using a titanium alloy cylindrical projectile and 3D fabric composite plates, with projectile velocities ranging from 160~280 m/s. Various impact test results such as rebound, embedding, and penetration were obtained, along with different damage forms of the composite target plate. Based on these test results, the impact properties and damage mechanisms of three different structural composites (3D 4 direction braided, 3D 5 direction braided, and 3D orthogonal woven) were analyzed. It is indicated that after being impacted by the projectile body, all three structures exhibit similar damage patterns characterized by local fiber fracture and matrix cracking at the point of impact without any lamination. The damage region of the 3D 4 direction braided structure is a sharp angle cross shape, while the damage spread along the braided direction. The damage region of the 3D 5 direction braided and 3D orthogonal woven structure are diamond-shaped, while the damage spread along the 90° and 0° direction. Comparing the three structures of specimens in this paper, it is found that the ballistic limit of 3D orthogonal woven structure is highest while its corresponding damage area is smallest.

Key words: 3D braided/woven, composites, ballistic impact test, impact properties, damage mechanism