Behavior of multi-cell steel columns under impact loading

This study investigates the behavior of multi-cell steel columns (MCCs) under impact loading through both experimental and numerical analysis. Twelve specimens, including single-cell columns (SCC) and four-cell MCC configurations, were tested in empty and concrete-filled conditions. The specimens were categorized into three groups based on a fixed height-to-width ratio (R). A nonlinear finite element model was developed using ABAQUS and validated against experimental data. Key parameters, including peak deflection, failure modes, deflection-time relationships, maximum impact forces, energy absorption and the rectangularity ratio effect, were examined to provide insights into impact-resistant structural design. The results demonstrate that the internal partitioning of the column into cells significantly reduces local buckling under impact loading by enhancing the section’s local stiffness. In addition, internal partitioning improves energy absorption for empty models. On the other hand, concrete-filled models do not show the same behavior although concrete filling significantly improves resistance to impact forces. The results also provides that increase of the R ratio results in an increase in impact force and a decrease in mid-point displacement. For empty single-cell columns, an increase in R results in a decrease in energy absorption, which may be due to energy dissipation through local buckling under the falling impactor. These findings contribute to the advancement of impact-resistant column designs for applications in structural and transportation engineering.