Damage analysis and energy absorption capacity of hollow square steel tubes subjected to conical hammer impact

Steel tubes find widespread applications in various structural elements, including load-bearing columns, stair guardrails, and security bollards, due to their high strength and durability. However, these structures are susceptible to damage under impact loading conditions. While prior studies have focused on drop hammer shapes like rectangles, wedges, cylinders, and hemispheres, research on the impact of a conical-shaped hammer on square and rectangular steel tubes remains limited. Therefore, this study aims to analyse the damage resulting from the impact of a conical-shaped hammer on square steel tubes using nonlinear Finite Element Analysis (FEA) software ABAQUS/Explicit. The investigation explores the effects of various parameters, including tube geometry, impact location, impactor mass, and impact height, on tube deformation and fracture behaviour of tube. Through comprehensive analysis, it was observed that the impacted site exhibited punching failure accompanied by inward bending of the tube, while outward buckling occurred at the support. The energy absorption process was examined, and the effect of the aforementioned parameters on the energy absorption capacity (EAC) was assessed. The findings indicate that the thickness of the steel tube has the most significant impact on the impact force and EAC. Additionally, the deflection of the tube was primarily influenced by the length of the hollow section.