Abstract
For a structural health monitoring (SHM) system, the operational functionality of sensors is critical for successful implementation of a damage identification process. This study presents experimental and analytical investigations on sensor fault diagnosis for impedance-based SHM using the piezoelectric interface technique. Firstly, the piezoelectric interface-based impedance monitoring is experimentally conducted on a steel bolted connection to investigate the effect of structural damage and sensor defect on electromechanical (EM) impedance responses. Based on the experimental analysis, sensor diagnostic approaches using EM impedance features are designed to distinguish the sensor defect from the structural damage. Next, a novel impedance model of the piezoelectric interface-driven system is proposed for the analytical investigation of sensor fault diagnosis. Various parameters are introduced into the EM impedance formulation to model the effect of shear-lag phenomenon, sensor breakage, sensor debonding, and structural damage. Finally, the proposed impedance model is used to analytically estimate the change in EM impedance responses induced by the structural damage and the sensor defect. The analytical results are found to be consistent with experimental observations, thus evidencing the feasibility of the novel impedance model for sensor diagnosis and structural integrity assessment. The study is expected to provide theoretical and experimental foundations for impedance monitoring practices, using the piezoelectric interface technique, with the existence of sensor faults.
Highlights
The electromechanical (EM) impedance method has been extensively investigated for structural integrity assessment of critical connections in civil structures [1,2,3,4,5,6]
To analytically interpret the influences of the sensor defects on the EM impedance and to demonstrate the theoretical feasibility of the proposed impedance model for sensor self-diagnosis and damage detection, a parametric study was conducted on a simple PZT interface-driven model [20]
To analytically interpret the influences of the sensor defects on the EM impedance and to corresponding to different values of the shear-lag index (γ = 1, 0.8, 0.6, 0.4, 0.2, 0). γ = 1 is an ideal demonstrate the theoretical feasibility of the proposed impedance model for sensor self-diagnosis case when the bonding layer has no influence on the EM impedance. γ = 0 and damage detection, a parametric study was conducted on a simple PZT interface-driven model indicates that the measured impedance will not contain any information about the interface and bolted
Summary
The electromechanical (EM) impedance method has been extensively investigated for structural integrity assessment of critical connections in civil structures [1,2,3,4,5,6]. The direct attachment of the PZT often leads to weak EM impedance responses and further results in difficulties in predetermining effective frequency bands for damage detection tasks [13,14,15] To overcome these issues, the piezoelectric-based smart interface technique (i.e., the PZT interface) has been developed as an alternative measurement for the PZT sensor [5,16,17,18]. The bonding layer’s defect would affect the force transmission from the PZT to the interface structure (via the shear mechanism) [23] These will result in observable changes in measured EM impedance responses, which would be falsely interpreted as the existence of structural damages. The analytical EM impedance modeling is validated by comparing the analytical results with the experimental observations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
