The bearing plate is an important part of a tendon–anchorage subsystem; however, its function and safety can be compromised by factors such as fatigue and corrosion. This paper explores the feasibility of the electromechanical impedance (EMI) technique for fatigue crack detection in the bearing plate of a prestressed anchorage. Firstly, the theory of the EMI technique is presented. Next, a well-established prestressed anchorage in the literature is selected as the target structure. Thirdly, a 3D finite element model of the PZT transducer–target anchorage subsystem is simulated, consisting of a concrete segment, a steel anchor head, and a steel bearing plate instrumented with a PZT transducer. The prestress load is applied to the anchorage via the anchor head. The EMI response of the target structure is numerically obtained under different simulated fatigue cracks in the bearing plate using the linear impedance analysis in the frequency domain. Finally, the resulting EMI response was quantified using two damage metrics: root-mean-square deviation and correlation coefficient deviation. These metrics are then compared with a threshold to identify the presence of cracks in the bearing plate. The results show that the simulated cracks in the bearing plate are successfully detected by tracking the shifts in the damage metrics. The numerical investigation demonstrates the potential of the EMI technique as a non-destructive testing method for assessing the structural integrity of prestressed structures.

For cable structures, the tension force is one of the main factors showing the structure’s health. If the tension force falls below a safe level during construction or operation, it can lead to partial or complete the structural failure, posing a risk to the people’s safety. In this study, a parallel structural health monitoring approach of the vibration-based and impedance-based methods is proposed to identify the tension force in cable structures. Firstly, a cable structure including the anchorage is simulated using a finite element model to obtain the vibration and impedance responses. The numerical results are verified with the experimental ones of the previous studies. Then, the parallel approach combining the above two methods is presented to determine the tension force. For the vibration-based method, the tension force is estimated by the natural frequencies. For the impedance-based method, the tension force is estimated by the mean absolute percentage deviation (MAPD) index and the artificial neural network (ANN). Finally, the tension force estimation results are compared and assessed. By using the parallel approach, the reliability and accuracy of the tension force identification results are guaranteed.

This study examined the feasibility of the admittance-based method for detecting simulated damage in the bearing plate of a prestressed anchorage. The proposed method utilized the PZT (lead zirconate titanate) interface technique to acquire a strong admittance response from the anchorage. Firstly, the numerical feasibility of the method was demonstrated by detecting the presence of fatigue cracks and preload changes in a fixed–fixed beam-like structure. Next, the experimental verification was carried out using a lab-scale prestressed anchorage model. A PZT interface prototype was designed and surface-mounted on the bearing plate. The admittance response of the PZT interface was measured before and after the simulated damage cases of the bearing plate. Afterwards, a statistical damage metric, root-mean-square deviation (RMSD) was used to quantify the change in the admittance spectrum and identify the damage’s presence. It was shown that the experimental admittance response was consistent with the numerical simulation result in the same effective frequency band. Both the numerical and experimental results showed clear shifts in the admittance spectrum due to structural damage. The simulated damages in the bearing plate were successfully identified by the RMSD evaluation metric.