【摘要】 进行了12个圆CFRP-钢管混凝土压弯构件的滞回性能试验研究。试验结果表明,CFRP对圆钢管混凝土有很好的环向约束和纵向增强作用,钢管的局部屈曲得到了延缓或消除。所有试件的跨中荷载-挠度曲线和弯矩-曲率曲线均较为饱满,表现出很好的滞回性能。在加载后期,无轴压力试件的承载力无下降,而有轴压力试件的承载力明显下降。对试验结果的分析表明,钢管和CFRP在纵向和环向都可以协同工作;同一点的纵向应变和环向应变异号;试件的挠曲线均近似为正弦半波曲线。计算表明,强度退化不显著,轴压比和纵向CFRP增强系数的增大可以提高试件的抗弯承载力和刚度,同时减缓刚度退化,但会降低试件的延性和累积耗能,而轴压比在一定范围内对试件的抗震性能是有利的。更多还原

【Abstract】 A total of 12 specimens were experimentally investigated to study the hysteretic behaviors of concrete filled circular CFRP-steel tubular beam-columns.The test results indicated that,CFRP can effectively provide circumferential confinement and longitudinal strengthening for the concrete filled circular steel tube,and the local bulking of the steel tube are delayed or prevented.Mid-span load-deflection hysteretic curves and moment-curvature hysteretic curves of all the specimens display perfect hysteretic behaviors.During the later loading period,there are not load bearing capacity drop for members without axial load,while there are obvious load carrying capacity drop for members with axial load.Analysis of the test results indicated that,the steel tube and its outer CFRP material can cooperate both longitudinally and circumferentially,the longitudinal strain and the circumferential strain of one same point have opposite sign,also,the deflection curves of all the members are approximately half sin wave.Calculation results showed that,the strength degradation is not obvious,axial compression ratio and strengthening factor of the longitudinal CFRP can enhance the bending strength and stiffness of the members and can delay stiffness degradation of the members,but they will decrease ductility and accumulated energy dissipation of the members,also,axial compression ratio is beneficial to seismic behaviors within certain range.更多还原