Response of reinforced concrete slabs to low-velocity projectile impact investigated using upper bound method

Abstract

Based on the incompressible-rigid-plastic material assumption and the slip line field theory, the resistance function of a rigid projectile penetrating a semi-infinite target at a low velocity was obtained with a single admissible velocity field. A three-stage resistance curve of a rigid projectile impacting on a thin target was analyzed under multiple velocity fields, where the critical conditions for scabbing or perforation were calculated. The methods and formulae for local effects on reinforced concrete slab under low-velocity impact were further verified using comparative analysis of the results from the experiments, the UMIST formulae, the Kuibyshev formulae, and the present paper's calculations. The relationships between the normalized critical scabbing/perforation thickness, and the nose-shape factor, the impact factor and the reinforcement factor were examined to present potential guide to experimental studies.