Numerical study on the hard projectile perforation on RC panels with LDPM

Abstract

This paper numerically investigates the medium-caliber hard projectile perforation of steel rebar reinforced concrete panels by using the recently developed Lattice Discrete Particles Model (LDPM). With mesoscale constitutive laws governing cohesive fracture, strain hardening in compression and compaction due to pore collapse, LDPM naturally captures the failure mechanisms at the length scale of coarse aggregate of concrete. A constant area and shape partition method for circular cross-section is employed to determine the Gauss integration points distribution for beam elements. The sliding friction model for rebar-concrete interaction, in conjunction with LDPM for concrete are utilized for RC panel perforation modeling. Simulations of normal and high strength concrete panel perforation tests are carried out to validate the numerical model whereby agreement with the experimental data is achieved in terms of projectile residual velocity as well as damage contour. Extensive simulations are further performed to investigate the effect of projectile impact location and reinforcement on high strength concrete (HSC) panel perforation responses. Comparative numerical studies indicate that the projectile residual velocity is significantly reduced when the projectile hits the reinforced rebars. Furthermore, the reinforcement can considerably limit the damage area, crack openings and prevent the concrete shelter from structural failure. Finally, the LDPM simulations of HSC panel perforation are combined with cavity expansion analysis to achieve the RC perforation analytical model whereas the target resistance parameter R (Forrestal et al., 2003) is determined a672 MPa while the shear plugging thickness value is estimated as 33 mm for the cases of interest.