ABSTRACT
Steel-plate concrete (SC) structures are increasingly adopted for protective infrastructure due to their superior energy absorption and robustness under extreme loading. However, the influence of internal connectors under high-velocity impact remains insufficiently understood. This study evaluates the effects of shear-stud spacing and tie-bar configuration on the impact resistance of SC panels using a detailed three-dimensional LS-DYNA model. The Karagozian & Case (K&C) concrete model with a user-defined dynamic increase factor calibrated from SHPB tests was employed to capture strain-rate-dependent concrete behavior. Steel faceplates and connectors were modeled with rate-sensitive plasticity and explicit steel–concrete interaction. Parametric analyses revealed that closer connector spacing enhances composite action but may intensify localized damage near the impact zone, whereas tie-bars improve through-thickness confinement and reduce global bulging. Numerical trends showed good agreement with available experimental results. These findings will directly inform an upcoming gas-gun experimental program and support improved design strategies for SC structures under extreme impact loading.
