基于频率变化的钢管混凝土柱损伤评价

摘要

To study the damage pattern after fatigue rupture of CFST column,the low-cyclic loading tests on six CFST columns under different drift ratio are carried on,and parameters of the CFST column are measured separately in good and damaged condition through the hammer test modal.The damage identification methods which combine modal frequency with finite element simulation are put forward based on the Ghtheobarah damage index,and the damage of CFST column under different working conditions is obtained by using this method.The results show that the method of the combination of modal frequency and finite element simulation is reliable.This method is similar to the result of damage index method based on frequency,and the regular pattern which total damage degree of CFST column after the fatigue damage increase with the increase of the drift ratio is obtained.%为研究钢管混凝土柱在疲劳破坏后的损伤规律,进行了6根钢管混凝土柱在不同侧移率工况下的低周往复试验,并通过锤击法模态测试获取钢管混凝土柱完好状态及破坏后的模态参数.基于Ghobarah损伤指标提出了模态频率与有限元模拟相结合的损伤识别方法,并利用此方法求得了不同工况下钢管混凝土柱的损伤.研究表明,利用模态频率与有限元模拟相结合的方法进行损伤评估结果真实可靠,此方法与基于频率的损伤指标方法计算结果相近,得出了钢管混凝土柱疲劳破坏后的总损伤程度随侧移率增加而增加的规律.