Penetration experiments and simulation of three-layer functionally graded cementitious composite subjected to multiple projectile impacts

Abstract

The three-layer functionally graded cementitious composite (FGCC) was prepared which consisted of crack resistance layer, anti-penetration layer and spalling resistance layer with different content of high strength fibers and coarse aggregates. The crack resistance layer and spalling resistance layer of FGCC were made of ultra-high performance hybrid fiber reinforced concrete and ultra-high performance steel fiber reinforced concrete respectively. The anti-penetration layer was made of ultra-high performance coarse aggregate concrete. The properties of FGCC targets subjected to three projectile impacts were researched. The fracture patterns were compared among different concrete targets. The penetration depth, crater diameter and damage area of different targets were measured. Results show that the penetration depth, crater diameter and damage ratio increased with the number of impact and were decreased by the reinforcement of high strength fibers and coarse aggregates. The cracking, penetration and spalling of concrete targets were controlled by the synergistic effects of the three different layers. The fracture process and damage development of FGCC subjected to three projectile impacts were simulated by smoothed particle hydrodynamics (SPH) method. The effect of the number of impact on the penetration depth, crater diameter, pressure and damage of FGCC were investigated.