钢管混凝土构件钢管与混凝土界面剥离损伤识别的试验研究

Study on Interface Debonding Defect Detection between the Steel and inner Concrete of a Concrete-Filled Steel Specimen

将压电陶瓷片制成嵌入式压电功能元预埋入模拟了局部界面损伤的钢管混凝土柱试件内作为驱动器,在试件钢管外壁粘贴压电陶瓷片作为传感器,驱动器在信号源产生的电压信号作用下产生激励信号,测量钢管混凝土柱试件的监测面上不同位置上传感器的输出电信号。基于压电陶瓷传感器输出信号的小波包总能量和小波包能量谱对界面剥离损伤进行了识别,分别定义了两个界面剥离损伤指标EI和WVWPES,为监测钢管混凝土柱内部混凝土与钢管壁界面粘结质量提供了新的思路。

An embedded PZT based function element is employed to detect the predesigned debonding damage in a concretefilled steel tubes （CFST） column specimen and a number of PZTs are bonded on predetermined locations of the outside surface of the CFST specimen as sensors. Laboratory tests are performed on the CFST column ; the responses of all the employed PZT sensors on the surfaces are measured when one of the embedded PZT is excited with sweep sinusoidal signals. Wavelet packet energy spectrums of the response of the PZT sensors are more regular than the wavelet packet energy and have nothing to do with the stress wave propagation path. Based on Wavelet packet energy and wavelet packet energy spectrums, two damage indexes are defined and the artificially mimicked debonding areas are detected successfully and the defined indexes are sensitive enough to the debonding damage. The method proposed in the paper provides a new way to monitoring debonding defect of concrete-filled steel tube.