Stress wave propagation and ballistic efficiency in ceramic composite armor: The influence of backplate material properties

• Penetration tests on composite armors with various backing plates showed increased ceramic and projectile fragmentation as plate strength and hardness increased. • Simulations revealed that with consistent fracture energy, higher plastic modulus in backing plates enhances ballistic resistance of ceramic composite armors. • A simplified model demonstrating one-dimensional stress wave propagation in the armor was developed to validate these findings. Stress wave intensity varied significantly between the ceramic and backing plate depending on whether the plate was in a plastic or elastic state. This study tested the dynamic mechanical properties of seven commonly used backing plate materials and conducted ballistic experiments on their corresponding ceramic composite armor. The distribution of projectile fragments was quantitatively analyzed via the Rosin–Rammler model to assess ballistic outcomes. The results indicated that as the dynamic yield strength of the backing plates increased, the degree of projectile fragmentation increased, whereas the extent of plastic deformation decreased. A model of ceramic composite armor was established to analyze the propagation of one-dimensional stress waves within the armor. Research has shown that when the backing plates are in an elastic state, the intensity of stress waves in the ceramic significantly increases, but in a plastic state, most stress waves dissipate within the backing plates, resulting in weaker stress waves in the ceramic. Numerical simulations further quantified the impact of the plastic modulus of the backing plates on armor performance. Maintaining constant strain energy while increasing the plastic modulus improved the stress state at the ceramic back, shifting from tensile to compressive wave dominance, thus enhancing the overall ballistic resistance of the armor. A high sound speed in the backing plates helps optimize the stress state within the armor, thereby enhancing its ballistic performance.