基于外贴压电陶瓷的钢管砼界面剥离检测机理的数值模拟研究

Numerical study on debonding detection mechanism for concrete filled steel tubular with external piezoceramic patches

界面剥离的存在会给钢管混凝土构件的力学性能带来负面影响,本文提出了一种利用外贴式压电陶瓷的应力波测量小波包分析的钢管混凝土构件界面剥离检测的方法。考虑压电陶瓷片的压电效应及与钢管混凝土构件的耦合效应,建立了二维多物理场耦合有限元模型;采用外贴压电陶瓷片作为驱动器和传感器,通过数值模拟研究了在简谐激励下不同缺陷试件压电传感器电压信号幅值及扫频信号激励下,不同缺陷试件传感器测量信号的小波包能量评价指标的变化规律。结果表明,界面剥离引起外贴压电陶瓷传感器电压信号幅值和测量信号的小波包能量下降,界面剥离越大,二者下降得越多。

The existence of interfacial debonding will have a negative effect on the mechanical properties of concrete filled steel tubular(CFST)members.In this paper,a defect detection approach for interfacial debonding of CFST members with surface mounted Piezoelectric Lead Zirconate Titanate(PZT)based on the wavelet packet analysis is proposed.Considering piezoelectric effects of PZT patches and the coupling effect between them and CFST,a two-dimensional multi-physical field coupling finite element model is established.Using surface mounted PZT as actuators and sensors,the change in output voltage signal amplitude of PZT sensor measurement and the wavelet packet energy based evaluation index corresponding to specimens with different interfacial debonding defects under sinusoidal excitation and swept sinusoidal signals,respectively,are studied numerically.The results show that the interfacial debonding defects lead to the decrease in the voltage signal amplitude and the wavelet packet energy of the signal of surface mounted PZT sensor measurement,and as the interfacial debonding increases,the more decrease.