Behavior of novel steel-concrete-steel sandwich walls under low-velocity impact loading

Abstract

This paper reported experimental and analytical studies on impact behaviors of steel-concrete-steel sandwich composite (SCSSC) walls using enhanced C-channels (ECs). Six SCSSC walls, designed with variations in impact energy levels and boundary columns, were tested by drop hammer and simulated by LS-DYNA. The main failure modes of the specimens after impact loading were global flexure and flexure-shear mode. As direct-link connections, the ECs provided strong interfacial shear and tensile resistances, which prevented local failure of SCSSC walls. Under three impact energy levels, boundary CSFT columns increased the ultimate impact resistance of SCSSC walls, and effectively reduces their peak displacements. Refined finite element (FE) models considering the effect of strain rate were established, and verified by reported impact test results. In addition, this study adopted modified two-degree-of-freedom (TDOF) model to estimate the impact force and displacement responses of this type of SCSSC walls. Validations against reported test results confirmed that the TDOF model provided reasonable predictions.