Dynamic responses of liquid-filled vessels impacted by a high-velocity projectile

Projectile impacts are a common safety problem for the fluid-filled structures. However, there is no universal theoretical approach to the quantitative characterization of this phenomenon, which restricts the associated hazard assessment. To address this issue, a theoretical model was proposed to describe the dynamic responses of liquid-filled vessels impacted by a high-velocity projectile, with a particular focus on the deformation of the vessel's rear plate. The model consists of three sub-models, i.e., the ballistic wave model, the fluid-structure interaction (FSI) model and the petal hole model. The proposed theoretical model accurately predicted the ballistic wave propagation and attenuation, as well as the interaction with the rear plate, which ultimately resulted in the formation of petal holes, in both ballistic impact experiments and finite element numerical simulations. Significant cavitation was observed at the interface between the rear plate and the fluid due to strong spatial nonlinearity of the ballistic wave, resulting in a shorter effective loading duration from the wave. The bending wave, which propagated from the center of the rear plate, caused a second acceleration of the rear plate with a duration of dozens of mu s, thereby contributing to energy conversion inside the rear plate. The initial kinetic energy Ek of the rear plate, with a maximum of approximately 3 kJ, and the projected area Sp of the petal hole with a maximum of approximately 180 cm2, were positively correlated with the impact velocity v0 of the projectile ranging from 1000 to 1600 m & sdot;s-1 and negatively correlated with the length L of the fluid ranging from 16 to 28 cm. This work offers new insights into the relationship between ballistic impact parameters and structural deformation.