钢管混凝土组合柱累积损伤性能试验研究

通过6个高轴压比下大尺寸钢管混凝土组合柱试件的拟静力试验，研究加载循环次数和配箍率对组合柱累积损伤性能的影响。试验结果表明：加载循环次数对组合柱试件承载力影响不大，对按全截面混凝土配箍设计（即计算体积配箍率时不扣除核心钢管混凝土体积）的组合柱试件的变形能力影响不显著，但对按钢管外混凝土配箍设计（即计算体积配箍率时扣除核心钢管混凝土体积）的试件变形能力影响较为显著。当循环加载10次时，按全截面混凝土配箍设计的试件变形能力和累积耗能能力显著优于按钢管外混凝土配箍设计的试件，前者的极限位移和失效位移分别比后者的大25%和41%，前者的总累积滞回耗能为后者的2.8倍。考虑地震作用下结构构件的累积损伤效应，建议钢管混凝土组合柱按全截面混凝土配箍设计，以保证足够大的变形能力。

Experimental study of cumulative damage performance of steel tube-reinforced concrete composite columns

This paper presents quasi-static tests of six large-scale steel tube-reinforced concrete (ST-RC) composite column specimens under high axial force ratio. The effects of the number of loading cycles and the volumetric transverse reinforcement ratio on cumulative damage performance of the ST-RC columns were investigated. The test results indicate that the number of loading cycles has minimal effect on the strength capacity of the specimens. The number of loading cycles has limited effect on the deformation capacity for the specimens of which the transverse reinforcement is designed based on the volume of all stirrup-confined concrete, while it obviously affects the deformation capacity for the counterpart specimens of which the transverse reinforcement is designed based only on the volume of the stirrup-confined concrete of RC encasement. When the lateral loading reverses ten cycles at each displacement level, the former specimen shows obviously larger deformation and cumulative energy dissipation capacities than the latter. The ultimate displacement and failure displacement of the former are 25% and 41% larger than those of the latter, and the total cumulative energy dissipated by the former is 2.8 times that of the latter. Allowing for the effect of cumulative damage of structures subjected to ground motions, the recommendation is made that the transverse reinforcement for the ST-RC columns should be designed based on the volume of all stirrup-confined concrete for ensuring adequate deformation capacity of the columns.