FRP 管约束十字钢骨混凝土组合柱抗侧向冲击试验研究

To solve steel corrosion in traditional steel-concrete composite structures, FRP (fiber reinforced polymer) tube-confined concrete-encased cross-shaped steel composite column (FCCSC) was proposed, which can be applied to bridge piers in corrosive environments. This study conducted multiple continuous impact tests on the lateral impact resistance performance of FCCSC. The failure modes, impact force, displacement and strain histories were recorded by data acquisition devices and compared to investigate the influence of impact position, impact energy and multiple impacts. The results show that the predominant failure modes in these FCCSC specimens are characterized by bending deformation. As column height increase, there is a reduction in the peak impact force, average impact force and equivalent impact force, along with an increase in the peak impact displacement and a prolongation of the impact duration. The impact force time history curve transitions from a single peak to a double peak. The displacement histories show the same trend but with different occurrence times for peak and other feature points at different locations. As the number of impacts increases, cumulative damage within FCCSC consistently grows. Under the same impact loading, the cumulative damage in the longer specimens is relatively small, but no local bucking phenomenon occurred in the steel of any FCCSC specimens, and the energy dissipation ratio is not less than 0. 55.