The Fracture Modes of Biomimetic Borosilicate Glass Protective Composite

The biomimetic structures in nature, such as shells, turtles, and other scaly organisms, inspire the design of transparent protective composites for enhancing their anti-penetration performance. Here, we designed the borosilicate glass composites with nacreous and tortoiseshell structures and examined their mechanical properties and damage mechanisms under high-speed impact using ballistics experiments. The effects of arrangements and tablet size on the dynamic performance of borosilicate glass composites were also investigated. The results suggest that the biomimetic structure exhibits better impact performance than traditional composites with whole plate structure. Using the biomimetic structure, the average damage area is decreased by 57.6-66.5% and the average energy dissipation is increased around 5% for the transparent composites. Compared to the aligned arrangements, the staggered arrangement of tablets is more beneficial to the anti-penetration when the staggered point is positioned symmetrically. In addition, the tablet size also plays a significant role, where a small tablet can decrease the average damage area around 15.4-24.1% and increase the average energy dissipation up to 4.2%. Therefore, the tortoiseshell structure with the staggered arrangement of small tablets is an optimal combination of the design parameters, which exhibits the best ballistic performance among other configurations due to the substantial enhancement of the locking effect at the tablet interface. This study provides valuable insights into the impact performance and fracture mode of the biomimetic structural composites, especially for the transparent armors of glass materials.