Dynamic response of high-strength CFST columns with BRBs structure under vehicle impact

High-strength square concrete-filled steel tubular columns with aluminum alloy buckling-restrained braces structure (HCFST-ALABS) may suffer from vehicle impacts during their service, leading to critical component failure and subsequently causing potential collapse. Research on its dynamic response can provide a basis for the design of structural collapse under impact loads. Based on the multi-scale modeling method, the entire stress process, damage evolution and failure mode, energy dissipation and internal force distribution of the impacted columns of the HCFST-ALABS under vehicle impact loads were analyzed. Key parameters such as position of impacted column, vehicle mass and velocity, constant kinetic energy-momentum changes, and cargo elastic modulus were systematically evaluated for their influence on structural damage. Finally, a simplified substructure model for evaluating the dynamic response of structures was proposed. The results showed that under vehicle impact, the impacted column of the HCFST-ALABS exhibited local plastic damage. As the impact progressed, the impacted column showed overall bending deformation, and the adjacent steel beams experienced local buckling. The plastic damage area of the brace expanded from the impacted column to the surrounding area. The impacted column was the primary component responsible for damage and energy dissipation in the HCFST-ALABS. Vehicle mass and speed were key factors influencing structural damage. The established substructure model achieved accurate prediction of the dynamic response and failure modes in the HCFST-ALABS, reducing computational time by 59.3% compared to the multi-scale model. • The complete mechanical response, progressive damage evolution, and ultimate failure mechanisms of HCFST-ALABS under vehicle impact loading. • The effects of impact position, vehicle mass and speed, constant kinetic energy-momentum changes, and cargo elastic modulus were analyzed. • The proposed substructure model can accurately predict the local dynamic response and failure mode of the structure.