Sensitivity Analysis of Johnson-Cook Material Constitutive Parameters for the Penetrator Core in High-Velocity Penetration by Long-Rod Projectiles

The Johnson-Cook constitutive model is extensively utilized in numerical simulations of high-velocity impact and penetration scenarios, with its primary material parameters (A, B, n, C, and m) directly governing the material’s flow stress. However, material parameters obtained exclusively through dynamic and static experiments generally prove inadequate for direct application in penetration analysis, necessitating further calibration for penetration studies. To investigate the influence of penetrator core material parameters on computational outcomes—particularly maximum penetration depth—during high-velocity penetration of semi-infinite metallic targets by long-rod projectiles, numerical simulations employing an experimentally validated ANSYS/LS-DYNA model were conducted. These simulations examined 93W alloy penetrator cores with varied material parameters impacting Rolled Homogeneous Armor steel at identical velocities. Results demonstrate that the initial yield strength (parameter A) constitutes the predominant factor influencing penetration depth; within the investigated range (500–2500 MPa), increasing A enhances penetration performance by 15.23%, while penetration depth sensitivity to the remaining parameters (B, n, C, m) remains below 5% across ranges typically covered by most materials.