冲击荷载作用后圆钢管柱抗震性能与恢复力模型研究

为研究冲击荷载作用后圆钢管柱的抗震性能，对12个受冲击荷载作用后的圆钢管柱和3个未受冲击荷载作用的对比柱进行了拟静力试验，研究了冲击高度和轴压比等因素对圆钢管柱破坏模式、滞回性能、延性、刚度退化和耗能能力的影响。基于拟静力试验结果，建立了考虑冲击高度和轴压比参数影响的圆钢管柱恢复力模型。结果表明：冲击高度和轴压比对圆钢管柱的滞回性能均有显著影响，随着冲击高度的增加，滞回曲线由饱满对称的梭形逐渐变为狭窄不对称的梭形，圆钢管柱水平承载力和变形能力逐渐下降，延性和耗能能力显著下降；随着轴压比的增长，滞回曲线的饱满程度显著降低，圆钢管柱承载力和极限位移减小，延性和耗能能力显著降低；受冲击荷载作用后的圆钢管柱恢复力模型计算结果与试验数据吻合良好，可用于工程结构的抗震弹塑性分析。

Research on seismic behavior and restoring force model of circular steel tubular columns after impacts

To study the post-impact seismic behavior of circular steel tubular columns, quasi-static tests were carried out on twelve circular steel tubular columns after being subjected to impacts and three columns without being subjected to impacts. The effects of impact height and axial compression ratio on the failure modes, hysteretic behavior, ductility, stiffness degradation and energy dissipation of the specimens were investigated. Based on the quasi-static tests, a restoring force model considering the effects of impact height and axial compression ratio was established. The research results indicate that both the impact height and axial compression ratio have significant effects on the hysteretic behavior of the specimens. With the increase of impact height, the hysteretic curves gradually change from full and symmetric spindle shape to narrow and asymmetric spindle shape, and the ultimate capacity and deformation capacity of the specimens decrease gradually, while the ductility and cumulative energy dissipation reduce remarkably. With the increase of axial compression ratio, the fullness of the hysteretic curves decreases evidently, the ultimate capacity and ultimate deformation of specimens decrease, and the ductility and cumulative energy dissipation deteriorate remarkably. The calculation results of the restoring force model for circular steel tubular columns after being subjected to impact are in good agreement with the test data, so the proposed model can be used for the seismic elastic-plastic analysis of engineering structures.