Numerical analysis and modeling of jacketed rod penetration

A computational study to assess terminal ballistic performance issues of adding a steel sheath, or jacket, to a depleted uranium (DU) penetrator has been performed. The CTH hydrocode was used to model DU penetrators with steel sheaths of various thicknesses against semi-infinite rolled homogeneous armor (RHA), finite RHA, and oblique plate targets. Guided by the initial results, additional semi-infinite RHA simulations were performed to support the development of a generalized penetration model for jacketed rods. The model computes RHA penetration as a function of impact velocity and normalized jacket thickness (thickness over diameter) and compares very favorably with experimental DU and steel data. The model indicates that “bulk” density (areal density) can considerably underestimate jacketed rod penetration. In addition, some insight into the penetrator and target flow shape factors (k_p and k_t) is obtained.