Numerical investigation on ballistic performance of coarse-aggregated layered UHPFRC
Y.Y.Y. Cao, Qingliang Yu, Wenhui Tang, H.J.H. Brouwers
Abstract
The impact resistance of coarse-aggregated layered Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) is investigated numerically with LS-DYNA. The Holmquist Johnson Concrete (HJC) model is employed to describe the dynamic behavior of the UHPFRC, and the effect of the coarse aggregates is reflected in the pressure-compaction relation. Mechanical tests are conducted to obtain the material-related inputs for the numerical model, and ballistic experiments are applied to calibrate the model parameter as well as to validate the simulation results. After valuation, the ballistic histories of the projectile and the penetration processes in the UHPFRC targets are analyzed. Furthermore, the study discusses the effects of the target thickness on the depth of penetration, showing the possibility to replace a thicker single-layered target by a thinner triple-layered one to achieve the same level of protection. Finally, perforation limits of the single- and tripled-layered UHPFRC at different impact velocities are estimated, based on which the ACE formulae are modified to accurately predict the perforation limit of the coarse-aggregated layered UHPFRC. The numerical simulations in this study reveal that the triple-layered target requires fewer dosages of cement and steel fibers in comparison to its single-layered counterpart with the same level of ballistic protection.