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Smart Structures and Systems
  Volume 19, Number 2, February 2017, pages 181-194
DOI: http://dx.doi.org/10.12989/sss.2017.19.2.181
 


Wave propagation simulation and its wavelet package analysis for debonding detection of circular CFST members
Bin Xu, Hongbing Chen and Song Xia

 
Abstract     [Full Text]
    In order to investigate the interface debonding defects detection mechanism between steel tube and concrete core of concrete-filled steel tubes (CFSTs), multi-physical fields coupling finite element models constituted of a surface mounted Piezoceramic Lead Zirconate Titanate (PZT) actuator, an embedded PZT sensor and a circular cross section of CFST column are established. The stress wave initiation and propagation induced by the PZT actuator under sinusoidal and sweep frequency excitations are simulated with a two dimensional (2D) plain strain analysis and the difference of stress wave fields close to the interface debonding defect and within the cross section of the CFST members without and with debonding defects are compared in time domain. The linearity and stability of the embedded PZT response under sinusoidal signals with different frequencies and amplitudes are validated. The relationship between the amplitudes of stress wave and the measurement distances in a healthy CFST cross section is also studied. Meanwhile, the responses of PZT sensor under both sinusoidal and sweep frequency excitations are compared and the influence of debonding defect depth and length on the output voltage is also illustrated. The results show the output voltage signal amplitude and head wave arriving time are affected significantly by debonding defects. Moreover, the measurement of PZT sensor is sensitive to the initiation of interface debonding defects. Furthermore, wavelet packet analysis on the voltage signal under sweep frequency excitations is carried out and a normalized wavelet packet energy index (NWPEI) is defined to identify the interfacial debonding. The value of NWPEI attenuates with the increase in the dimension of debonding defects. The results help understand the debonding defects detection mechanism for circular CFST members with PZT technique.
 
Key Words
    piezoceramics; concrete-filled steel tube; debonding defect; identification; wave propagation method; numerical simulation; wavelet packet analysis
 
Address
Bin Xu: College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, China;
Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province (Huaqiao University),
Xiamen, Fujian 361021, China
Hongbing Chen: College of Civil Engineering, Hunan University, Changsha, Hunan 410082, China
Song Xia: School of Electric and Information Engineering, Xi\'an Jiaotong University, 28 Xianning West Road, Xi\'an, Shaanxi, 710049, P.R. China

 

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