Numerical and Theoretical Investigation on the Dynamic Behavior of Steel-Concrete-Steel Composite Panels Under Low-Velocity Impact

Steel-concrete-steel composite (SCS) panels have been extensively utilized in structural engineering and are vulnerable to impact loading during their service life. Therefore, this work numerically and theoretically investigated the low-velocity impact performance of SCS panels. Firstly, based on the existing drop-hammer impact experiments, three-dimensional finite element (FE) models incorporating material failure and strain-rate effect were constructed using ABAQUS and employed to predict the dynamic responses of SCS panels subjected to impact loading. After verifying the reliability of numerical models with test results, the impact-resistant mechanism of these members was analyzed. Then, a parameter analysis was carried out to systematically explore the influences of essential parameters on the impact responses of SCS panels. Results indicated the sandwiched concrete played a predominant role in absorbing impact energy. The proportion of plastic energy absorbed by the concrete reduced by approximately 11% with increasing impact height from 3.0 m to 4.5 m. The steel plate ratio had a marginal effect on the impact response under the constant panel thickness, while the variations in impact velocities, boundary conditions, and axial-load levels significantly affected it. As the axial load ratio reached 0.6, the instability occurred due to severe buckling of steel faceplates. Finally, an empirical formula for calculating the local bulging stiffness of bottom steel faceplate was proposed. The revised calculation method was able to accurately predict the post-peak mean force and the mid-span deflection of bottom steel faceplate.