π型钢-混凝土组合梁界面的疲劳损伤监测

Interface fatigue damage monitoring of π shaped steel-concrete composite beams

π型钢-混凝土组合梁新型结构在服役期间长期处于疲劳荷载作用下,对其界面进行疲劳损伤监测是很有必要的。提出了一种基于压电陶瓷的主动传感波动监测方法并进行了监测试验,该方法通过对比每个传感器在健康状态以及不同疲劳加载次数状况下所接收到的时域信号和小波包能量的变化,来判断π型钢-混凝土组合梁界面的损伤状态。试验结果表明,增加循环荷载的疲劳次数,各传感器响应信号的时域信号幅值和小波包能量都会呈现出整体下降的趋势;时域信号分析和小波包能量分析均能反映试件的损伤程度,且小波包能量分析方法的敏感程度更高;π型钢-混凝土组合梁界面具有较好的疲劳黏结性能,基于压电陶瓷的主动传感监测方法具有可行性。

The new structure of π shaped steel-concrete composite beam has been under fatigue load for a long time during service, and it is necessary to monitor the fatigue damage of its interface. An active sensing wave monitoring method and monitoring test based on piezoelectric ceramics is proposed. The method is to judge the damage state of the interface of π shaped steel-concrete composite beam by comparing the time domain signal and wavelet packet energy changes received by each sensor under the health state and different fatigue loading times. The results show that, increasing the fatigue times of cyclic load, the time domain signal amplitude and wavelet packet energy of each sensor response signal show an overall downward trend. Both time domain signal analysis and wavelet packet energy analysis can reflect the damage degree of specimen, and the wavelet packet energy analysis method has higher sensitivity, the π shaped steel-concrete composite beam interface has good fatigue bonding performance, the active sensing monitoring method based on piezoelectric ceramics is the feasible.