基于表面压电波动测量的钢管砼剥离检测试验

钢管混凝土结构结合了钢管与混凝土两者的力学优点，具有优越的力学性能，被广泛应用于超高层建筑和大跨度桥梁中，但钢管管壁与内部核心混凝土间的界面剥离将会对其承载力等力学性能带来负面影响。该文提出一种通过在钢管壁同侧布置压电陶瓷片作为驱动器和传感器，基于表面波动测量的矩形截面钢管混凝土构件的界面剥离缺陷检测方法，通过在一矩形截面钢管混凝土柱钢管的四面内壁设置不同程度剥离缺陷进行测试，对比简谐激励下健康工况和不同尺寸缺陷工况下压电传感器测量信号幅值，定义界面损伤指标实现了管壁界面剥离缺陷检测。结果表明,基于表面波动测量的钢管混凝土柱内部界面剥离缺陷状况检测方法有效，损伤指标与损伤程度相关。

Experiment on Interface Debonding Detection for Concrete Filled Steel Tubular Structure Using Surface Wave Measurement

The concrete filled steel tubular (CFSTs) structure combines the mechanical advantages of both steel tubular and concrete and has widely used in super high rise buildings and large span bridges due to its excellent mechanical properties. However, the debonding between the steel tubular and the confined concrete core leads to negative effects on the mechanical properties including load carrying capacity. In this paper, an interface debonding detection approach for a rectangular CFST specimen using surface stress wave measurement excited by a surface mounted piezoelectric ceramic (PZT) patch on the same side of tubular is proposed. A rectangular CFST specimen with different interface debonding defects on the four inner surfaces is tested and the measurement of the surface mounted PZT patch under sinusoidal excitation signals is analyzed. The comparison between the signal amplitude of piezoelectric sensor measurement under harmonic excitation in healthy condition and defect condition with different size was carried out. The interface damage index is defined to achieve the detection of pipe wall interface peeling defects. The results show that the proposed approach can effectively identify the debonding defect of the CFSTs and the defined index is dependent on the severity of the debonding.