Perforation of Reinforced Concrete Slabs by Rigid Missiles

This paper presents an extension of the penetration theory proposed by the National Defense Research Committee (NDRC). The extension is based on experimental studies, performed over the last few years and covering projectiles with lower impact velocities and larger diameters and weights than originally considered by the NDRC. The missiles are considered to be rigid, that means that no deformation of the missile is taken into account. The paper gives a new expression for the calculation of the perforation thickness for the above mentioned range of missiles and a new formulation of the velocity function is proposed, allowing the estimation of residual velocity after perforation. The new formulation preserves the advantages of the NDRC formula and leaves the basic expression unchanged. The impact time and the reaction force are calculated based on the new velocity function. The results are compared with the experiments.