碳纤维布加固方钢管混凝土柱恢复力模型研究

Study on Restoring Force Model of CFRP-strengthened CFSST Columns

通过对3根方钢管混凝土柱低周反复荷载试验,得到了碳纤维布加固柱的滞回曲线和强度退化规律,分析了轴压比对碳纤维布加固试件抗震性能的影响。试验结果表明,碳纤维布加固能增强方钢管混凝土柱的抗震性能,是一种有效的加固方法。基于试验结果,采用回归分析的方法建立了碳纤维布加固方钢管混凝土柱的恢复力模型,并详细描述了该模型的滞回规则。该模型的骨架曲线由弹性段、硬化段、退化段组成三折线骨架曲线,给出了骨架曲线各阶段刚度计算公式。比较试验骨架曲线与计算值可知,两者较为符合,所提出的恢复力模型能较全面的反映试件的实际受力性能,可供碳纤维布加固钢管混凝土柱及其结构非线性地震反应分析及抗震加固应用。

In order to set up the restoring force model of concrete-filled square steel tubular(CFSST)columns strengthened by CFRP,three CFSST columns were tested under low cyclic loading,the hysteretic loops and the law of strength deterioration under low cyclic loading were obtained.The experimental results show that the method of CFRP-strengthened could increase the seismic behavior of CFSST columns,and it is an efficient method of columns strengthening.Based on the experimental data,the restoring force model of the CFRP-strengthened CFSST columns was built through regression analysis method,and the hysteretic rule of the restoring force was described model in detail.The skeleton curve of this model was composed of elastic segment,hardening segment and degradation segment,and the calculation formulas of stiffness parameter in restoring force model at different stages of deformation were also presented.Through the comparison between the tests and the calculated results skeleton curve,the results agree with the test results,and the restoring force model can reflect the mechanical performance of specimen.The model can be used for nonlinear seismic response analysis of CFSST columns and its structure and the seismic strengthening design.