Study of the axial density/impedance gradient composite long rod hypervelocity penetration into a four-layer Q345 target

Based on the dynamic shock response of the material and structure, the hypervelocity impact processes and mechanisms of long composite rods with axial density/impedance gradients penetration into four-layer targets were studied through experiments and numerical simulation methods. The propagation law of the shock waves, together with the structural responses of the projectiles and targets, the formation and evolution of the fragment groups formed during the processes and their distributions were described. The damage of each target plate was quantitatively analysed by comparing the results of the experiment and numerical simulation. The results showed that the axial density/impedance gradient projectiles could decrease the impact pressure to a certain extent, and the degree of damage to the target plate decreased layer by layer when the head density/impedance of the projectile was high. When the head density/impedance of the projectile was low, the degree of target damage first increased layer by layer until the projectile was completely eroded and then it decreased. The results can provide a reference for the design and application of long rods with axial composite structure for velocities ranging from 6 to 10 Ma or greater.