A parametric study on the high-velocity projectile impact resistance of UHPC using the modified K&C model

This paper presents a comprehensive parametric study on the influence of various aspects on the depth of penetration (DOP) and equivalent crater diameter (ECD) of ultra-high performance concrete (UHPC) caused by high-velocity projectile impact (HVPI) using a modified K&C model. Parameters selected for the investigation include the material properties of UHPC (compressive strength, tensile strength, toughness, elastic modulus, density and dynamic increase factor (DIF)), specimen dimensions (thickness and width), and test conditions (projectile nose shape and striking velocity). Within the range of the investigated material parameters of UHPC, the compressive strength and DIF under compression are the most influential ones for the DOP, while the tensile strength and DIF under tension have the greatest influence on the ECD. It was also found that the Li-Chen equation outperforms other commonly used equations in predicting the DOP of UHPC subjected to HVPI. The findings of this paper facilitate the understanding on the key parameters dictating the resistance of UHPC subjected to HVPI, which shed light on the opti-mization of UHPC mixture design for the applications in protective structures.