Smart PZT-interface for wireless impedance-based prestress-loss monitoring in tendon-anchorage connection

This paper presents an overview of currently available methods for monitoring prestressing forces in prestressed concrete structure. Structural health monitoring has become an increasingly important tool for assessment of structural performance. Additionally, the value of the prestressing force represents an important parameter in prestressed concrete structures. Thus, several methods for monitoring prestress forces have emerged. This paper aims to consolidate the work performed in the area of prestressing force monitoring by presenting the most important advances and the directions for future research. The methods presented in this paper are based on indirect monitoring of the prestressing force through monitoring of another relevant parameter. They are divided into five general classes based on the relevant parameter they monitor:(a) vibration-based methods (based on acceleration), (b) impedance-based methods (based on electrical impedance), (c) acoustoelastic methods (based on wave velocity), (d) elasto-magnetic methods (based on magnetic permeability), and (e) strain-based methods (based on strain). The paper presents a table summarizing the comparison between the methods based on defined criteria.

Section: Impedance‐based Methodsmentioning

confidence: 99%

Section: Impedance‐based Methodsmentioning

confidence: 99%

Monitoring of prestressing forces in prestressed concrete structures—An overview

Abdel-Jaber

Glišić

2019

“…In many cases, the measured frequency bands can be higher than 100 kHz to sensitively capture incipient damage in structures . This causes the difficulty for the implementation of low‐cost impedance sensing devices which allow frequency ranges below 100 kHz . To overcome this limitation, Huynh and Kim proposed a PZT interface method that can acquire impedance responses sensitive to structural properties at predetermined frequency bands less than 100 kHz.…”

Section: Impedance Monitoring Methods For Prestressed Tendon Anchoragementioning

confidence: 99%

“…As schematized in Figure , the proposed method requires only the impedance signals of the healthy state for training the network. Therefore, the collection of the training data from the in situ target structures can be feasible by using wire/wireless impedance monitoring systems . The number of collected impedance data can be also minimized via evaluating the performance of the proposed RBFN‐based method.…”

Section: Rbfn‐based Temperature Compensation Algorithm For Damage Detmentioning

confidence: 99%

“…Therefore, the collection of the training data from the in situ target structures can be feasible by using wire/wireless impedance monitoring systems. [18][19][20]31] The number of collected impedance data can be also minimized via evaluating the performance of the proposed RBFN-based method. The above features make the proposed RBFN-based scheme become simple and feasible for real implementations on in situ structures.…”

Section: Figurementioning

confidence: 99%

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RBFN-based temperature compensation method for impedance monitoring in prestressed tendon anchorage

Huynh

Kim

2018

Self Cite

Summary In this study, a temperature compensation method based on radial basis function network (RBFN) is developed to monitor damage‐induced impedance signatures in prestressed tendon anchorages under temperature variation. First, an impedance monitoring technique via a piezoelectric interface device is outlined for prestress‐loss detection in the tendon anchorage system. Second, an RBFN‐based algorithm is designed to filter out the temperature‐induced variation in impedance signatures for damage monitoring. Finally, the feasibility of the proposed algorithm is verified for the prestress‐loss monitoring in the test structure under the temperature‐varying condition. A series of impedance measurements are conducted for the temperature‐varying and prestress force‐varying conditions. The RBFN‐based algorithm is used to train a set of baseline impedance signatures for varying temperatures, and also to quantify damage‐induced impedance signatures of the test structure. The effect of the size of RBFN training patterns on the accuracy of the proposed temperature compensation algorithm is also evaluated.

Damage‐sensitive impedance sensor placement on multi‐strand anchorage based on local stress variation analysis

Dang

Huynh

Pham

et al. 2020

Summary An important issue in impedance‐based damage monitoring is to deploy sensors in proper positions in which damage‐sensitive impedance responses can be captured effectively. In this study, a full‐scale multi‐strand anchorage is analyzed to determine optimal locations of piezoelectric sensors for impedance‐based monitoring of locally damaged strands. First, stress variations of the multi‐strand anchorage are experimentally measured to estimate the anchorage behavior under the effect of locally damaged strands. Strain signals are examined for axial, circumferential, and radial stress components under the variation of prestress forces. Second, a finite element analysis is made on the multi‐strand anchorage to back up the experimental findings. Third, a damage‐sensitive structural model is interpreted for the local strand breakage. Finally, impedance responses sensitive to local strand breakage are experimentally examined for a few scenarios simulated in the anchorage system. PZT (lead zirconate titanate) sensors deployed on the anchor head and the bearing plate are evaluated to comparatively determine ideal regions of interest for impedance monitoring. The results show that the greater stress variation yields the greater variations in impedance responses and the near‐top and near‐anchor heads are ideal regions of interest for damage‐sensitive impedance monitoring.