scholarly journals Health Monitoring of Bolt Looseness in Timber Structures Using PZT-Enabled Time-Reversal Method

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Ze Zhao ◽  
Pengcheng Chen ◽  
En Zhang ◽  
Guoyun Lu
Keyword(s):  
Wavelet Analysis ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Time Reversal ◽  
Lead Zirconate ◽  
Maintenance Cost ◽  
Timber Structures ◽  
Prestress Loss ◽  
Loss Index ◽  
Bolt Connection

A prestressed bolt connection is one of the crucial connection types in timber structures. The daily checking and maintenance of bolt connections have to be carried out in order to avoid the collapse of timber structures due to bolt looseness. Real-time health monitoring of bolt connections can not only reduce the daily maintenance cost of timber structures, but it can also avoid property loss and casualties by giving early warning if the bolt connection is loosened in timber structures. This paper proposes a method of prestress monitoring of bolt joints in timber structures by pasting lead zirconate titanate (PZT) patches on the surface of timber structures, and the time-reversal method is applied to denote the connection status of bolts in timber structures. The prestress loss index of timber structural bolts based on wavelet analysis is designed to quantify the bolt looseness of the timber structure. The experimental timber specimen was fabricated consisting of two timber panels, one bolt, and two PZT patches. One of the PZT patches acted as an actuator to emit the stress waves, and another one acted as a sensor to receive the stress wave propagating through the connection interface. The experimental results showed that the amplitude of the focused signal increases significantly with the increase of the prestress value of the bolts, which verify that the proposed method can be utilized to monitor the looseness of bolts in timber structures. The analysis results of the focused signal is proof that the prestress loss index of timber structural bolts designed based on wavelet analysis can reflect the looseness of timber structural bolts.

Development of PZT fiber rosette to locate acoustic source

2021 ◽  
pp. 1045389X2199192
Author(s):  
Bao Chi Ha ◽  
Kevin Gilbert ◽  
Gang Wang
Keyword(s):  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Lamb Wave ◽  
Lead Zirconate ◽  
Acoustic Source ◽  
Mechanical Coupling ◽  
Monitoring Applications ◽  
Commercial Off The Shelf ◽  
Lamb Wave Propagation ◽  
Strain Direction

Because of their electro-mechanical coupling property, Lead-Zirconate-Titanate (PZT) materials have been widely used for ultrasonic wave sensing and actuation in structural health monitoring applications. In this paper, a PZT rosette concept is proposed to conduct Lamb wave-based damage detection in panel-like structures by exploring its best directional sensing capability. First, a directivity study was conducted to investigate sensing of flexural Lamb wave propagation using a PZT fiber having d33 effects. Then, commercial off-the-shelf PZT fibers were polarized in-house in order to construct the PZT rosette configuration, in which three PZT fibers are oriented at 0°, 45°, 90°, respectively. Since Lamb wave responses are directly related to measured PZT fiber voltage signals, a simple interrogation scheme was developed to calculate principal strain direction in order to locate an acoustic source. Comprehensive tests were conducted to evaluate the performance of the proposed PZT rosette using an aluminum plate. It is shown that the PZT rosette is able to sense Lamb wave responses and accurately locate an acoustic source. We expect to further evaluate the PZT rosette performance when damages are introduced.

scholarly journals A New Structural Health Monitoring Strategy Based on PZT Sensors and Convolutional Neural Network

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2955 ◽  
Author(s):  
Mario de Oliveira ◽  
Andre Monteiro ◽  
Jozue Vieira Filho
Keyword(s):  
Neural Network ◽  
Structural Health Monitoring ◽  
Convolutional Neural Network ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Lead Zirconate ◽  
Industrial Applications ◽  
Electromechanical Impedance ◽  
Structural Health

Preliminaries convolutional neural network (CNN) applications have recently emerged in structural health monitoring (SHM) systems focusing mostly on vibration analysis. However, the SHM literature shows clearly that there is a lack of application regarding the combination of PZT-(lead zirconate titanate) based method and CNN. Likewise, applications using CNN along with the electromechanical impedance (EMI) technique applied to SHM systems are rare. To encourage this combination, an innovative SHM solution through the combination of the EMI-PZT and CNN is presented here. To accomplish this, the EMI signature is split into several parts followed by computing the Euclidean distances among them to form a RGB (red, green and blue) frame. As a result, we introduce a dataset formed from the EMI-PZT signals of 720 frames, encompassing a total of four types of structural conditions for each PZT. In a case study, the CNN-based method was experimentally evaluated using three PZTs glued onto an aluminum plate. The results reveal an effective pattern classification; yielding a 100% hit rate which outperforms other SHM approaches. Furthermore, the method needs only a small dataset for training the CNN, providing several advantages for industrial applications.

An experimental study on piezoelectric energy harvesting from wind and ambient structural vibrations for wireless structural health monitoring

2019 ◽  
Vol 23 (5) ◽  
pp. 1010-1023 ◽  
Author(s):  
Naveet Kaur ◽  
Dasari Mahesh ◽  
Sreenitya Singamsetty
Keyword(s):  
Structural Health Monitoring ◽  
Energy Harvesting ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Lead Zirconate ◽  
Piezoelectric Energy Harvesting ◽  
Structural Vibrations ◽  
Ambient Wind ◽  
Piezoelectric Energy ◽  
Zirconate Titanate

Energy harvesting is an emerging technology holding promise of sustainability amid the alarming rate at which the human community is depleting the natural resources to cater its needs. There are several ways of harvesting energy in a renewable fashion such as through solar, wind, hydro-electric, geothermal, and artificial photosynthesis. This study focuses on energy harvesting from wind vibrations and ambient structural vibrations (such as from rail and road bridges) through piezo transducers using the direct piezoelectric effect. First, the potential of the piezoelectric energy harvesting from ambient wind vibrations has been investigated and presented here. Lead zirconate titanate patches have been attached at the fixed end of aluminum rectangular and trapezoidal cantilevers, which have been exposed to varying wind velocity in a lab-size wind tunnel. The effect of perforations and twisting (distortion) on the power generated by the patches under varying wind velocity has also been studied. It has been observed that the power is comparatively higher in rectangular-shaped cantilever than the trapezoidal one. Perforations and shape distortion showed promising result in terms of higher yield. The laboratory experiments have also been extended to the real-life field condition to measure the actual power generated by the lead zirconate titanate patches under the ambient wind vibrations. Next, energy harvesting from the ambient structural vibrations has been done both experimentally and numerically. Four different prototypes have been considered. The power has been measured across the lead zirconate titanate patches individually and in parallel combination. A maximum power output for Prototype 1 to Prototype 4 has been found to be 4.3428, 11.844, 25.97, and 43.12 µW, respectively. Numerical study has also been carried out in ANSYS 14.5 to perform the parametric study to examine the effect of addition of mass at the free end of cantilever. In a nutshell, this article provides a comprehensive study on the effect of various factors on the amount of energy generated by piezoelectric patches under wind and structural vibrations. The energy generated is sufficient for driving low-power-consuming electronics that can further be used for other applications like wireless structural health monitoring, and so on.

Piezoelectric sensor–based damage progression in concrete through serial/parallel multi-sensing technique

2019 ◽  
Vol 19 (2) ◽  
pp. 339-356 ◽  
Author(s):  
Balamonica K ◽  
Jothi Saravanan T ◽  
Bharathi Priya C ◽  
Gopalakrishnan N
Keyword(s):  
Damage Detection ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Structural Damage ◽  
Data Retrieval ◽  
Lead Zirconate ◽  
Structural Damage Detection ◽  
Retrieval Process ◽  
Zirconate Titanate ◽  
In Series

Structural damage detection using unmanned Structural Health Monitoring techniques is becoming the need of the day with the technologies available presently. Sensors made of Lead Zirconate Titanate materials, due to their simplicity and robustness, are increasingly used as an effective monitoring sensor in Structural Health Monitoring. Continuous monitoring of the structures using Lead Zirconate Titanate sensors often results in a laborious data retrieval process due to the large amount of signal generated. To speed up the data retrieval process, a multi-sensing technique in which the Lead Zirconate Titanate patches are connected in series and parallel is proposed for structural damage detection. The proposed method is validated using an experimental investigation carried out on a reinforced concrete beam embedded with smart Lead Zirconate Titanate sensor units. The beam is subjected to damage, and the location of damage is identified using conductance signatures obtained from patches sensed individually and through multiplexing. This article proposes an effective methodology for selection of patches to be connected in series/parallel to maximise the efficiency of damage detection. Damage quantification using conventional statistical metrics such as root mean square deviation, mean absolute percentage deviation and cross correlations are found to be ineffective in identifying the location of damage from the multiplexed signatures. In turn, dynamic metrics such as moving root mean square deviation, moving mean absolute percentage deviation and moving cross correlation with overlapped moving blocks of data are proposed in the present work and their ability to detect the damage location from multiplexed signatures is discussed.

Interfacial debonding detection in fiber-reinforced polymer rebar–reinforced concrete using electro-mechanical impedance technique

2017 ◽  
Vol 17 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Weijie Li ◽  
Shuli Fan ◽  
Siu Chun Michael Ho ◽  
Jianchao Wu ◽  
Gangbing Song
Keyword(s):  
Reinforced Concrete ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Mechanical Impedance ◽  
Lead Zirconate ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Monitoring Technique

For reinforced concrete structures, the use of fiber-reinforced polymer rebars to replace the steel reinforcement is a topic that is receiving increasing attention, especially where corrosion is a serious issue. However, fiber-reinforced polymer rebar–reinforced concrete always carries the risk of structural failure initiated from the debonding damage that might occur at the reinforcement–concrete interface. This study employed an electro-mechanical impedance–based structural health monitoring technique by applying lead–zirconate–titanate ceramic patches to detect the debonding damage of a carbon fiber–reinforced polymer rebar reinforced concrete. In the experimental study, a carbon fiber–reinforced polymer rebar reinforced concrete specimen was fabricated and it was subjected to a pullout test to initiate the debonding damage at the reinforcement–concrete interface. The impedance and admittance signatures were measured from an impedance analyzer according to the different debonding conditions between the reinforcement and the concrete. Statistical damage metrics, root-mean-square deviation and mean absolute percentage deviation, were used to quantify the changes in impedance signatures measured at the lead–zirconate–titanate patches due to debonding conditions. The results illustrated the capability of the electro-mechanical impedance–based structural health monitoring technique for detecting the debonding damage of fiber-reinforced polymer rebar–reinforced concrete structures.

Durability of Embedded PZTs in Structural Health Monitoring Systems under Cyclic Loading

2014 ◽  
Vol 891-892 ◽  
pp. 1255-1260 ◽  
Author(s):  
Sanghyun Yoo ◽  
Akbar Afaghi Khatibi ◽  
Everson Kandare
Keyword(s):  
Cyclic Loading ◽  
Structural Health Monitoring ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Low Cycle Fatigue ◽  
Maintenance Cost ◽  
Clear Understanding ◽  
Structural Health ◽  
Service Conditions

Structural Health Monitoring (SHM) systems are developed to decrease the maintenance cost and increase the life of engineering structures by fundamentally changing the way structural inspections are performed. However, this important objective can only be achieved through the consistent and predictable performance of a SHM system under different service conditions. The capability of a Piezoelectric lead Zirconate Titanate (PZT)-based SHM system in detecting structural flaws strongly depends on the sensor signals as well as actuator performance. But service conditions can change the behaviour of transducers, raising questions about long term SHM system capability. Although having a clear understanding of the reliable sensor life is important for surface mounted systems, however, this is particularly critical for embedded sensors. This is due to the fact that opportunity for replacement of sensors exists for surface bonded transducers while for the embedded systems, sensor replacement is not straightforward. Therefore, knowledge of the long term behaviour of embedded-SHM systems is critical for their implementation. This paper reports a study on the degradation of embedded PZT transducers under cyclic loadings. Carbon/epoxy laminates with an embedded PZT were subjected to fatigue loading and their performance was monitored using Scanning Laser Vibrometery (SLV). The functionality of PZT transducers under sensing and actuating modes were studied. High and low cycle fatigue tests were performed to establish strain-voltage relationships which can be used to identify critical cyclic loading parameters (number of cycles and R value) under sensing and actuating modes.

Monitoring Vibrating Structures Using PZT Impedance Transducers

2008 ◽  
Vol 47-50 ◽  
pp. 85-88
Author(s):  
Ai Wei Miao ◽  
Yao Wen Yang
Keyword(s):  
Experimental Study ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Lead Zirconate ◽  
Frequency Range ◽  
External Excitation ◽  
Real Situation ◽  
Electromechanical Impedance ◽  
Structural Health ◽  
Vibrating Structures

Electromechanical impedance (EMI) technique using lead zirconate titanate (PZT) transducers has been increasingly applied to structural health monitoring (SHM) of aerospace, civil and mechanical structures. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in the electromechanical admittance (inverse of EMI) signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the monitored structure is only excited by the PZT transducers for the interrogating of EMI signature, while the vibration of the structure caused by the external excitations other than the PZT actuation is not considered. However, in real situation many structures work under vibrations. To monitor such structures, issues related to the effects of vibration on the EMI signature need to be addressed because these effects may lead to misinterpretation of the structural health. This paper develops an EMI model for beam structures, which takes into account the effect of beam vibration caused by the external excitations. An experimental study is carried out to verify the theoretical model. A Lab sized specimen with external excitation is tested and the effect of excitation on EMI signature is discussed.

Structural Health Monitoring of High Temperature Composites

2011 ◽  
Author(s):  
Nathan Salowitz ◽  
Yu-Hung Li ◽  
Sang-Jong Kim ◽  
Surajit Roy ◽  
Fu-Kuo Chang
Keyword(s):  
High Temperature ◽  
Structural Health Monitoring ◽  
Polymer Matrix ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Polymer Matrix Composites ◽  
Lead Zirconate ◽  
Baseline Data ◽  
Matrix Composites ◽  
Diagnostic Algorithms

High-temperature polymer-matrix composites (PMCs) are necessary and critical for the development of supersonic aircraft and orbital re-entry vehicles because of the need for light-weight design, high strength-to-weight ratios and high thermal stability in structures. Damage detection is a primary concern in composite structures because they are prone to multiple damage forms that can be hidden within the structure. Damage can include matrix cracking, fiber breakage, and delamination which can be caused by impacts, fatigue, or overloading. To overcome these shortfalls highly damage tolerant structures are employed to improve the safety of structures. Unfortunately this requires additional, potentially unnecessary, structural weight which is detrimental to aerospace structures. Acoustic ultrasound based structural health monitoring (SHM) has demonstrated the ability to overcome these problems by using arrays of Lead Zirconate Titanate piezoelectric transducers typically mounted on a flex circuit all of which is permanently affixed to, or embedded within, a structure [1] [2] [3] [4]. These transducers can excite and detect ultrasonic wave propagation in the structure and diagnostic algorithms, interpreting the signals, have been developed enabling real time inspection for damage. However, modern SHM systems are not capable of surviving the high temperatures experienced in the fabrication and service of High-temperature polymer matrix composites. In particular the Lead Zirconate Titanate piezoelectric elements typically depolarize and lose their functionality at around 200°C [5] [6]. Additionally, current SHM diagnostic algorithms are dependent on baseline data to compare signals to. These signals change with temperature and even just a few degree change can be detrimental to the system’s abilities. The current method for enabling functionality over a range of temperatures is to take numerous sets of baseline data at very high resolution across a range of temperatures. In order to adapt SHM for high temperature composites new piezoelectric materials must be developed capable of surviving elevated fabrication and operational temperatures. Small scale network components must be integrated to reduce detrimental effects of embedding SHM systems within the composite layup [7] [8] [9]. Additionally, methods for reducing the number of baseline data sets in the diagnostic algorithms must be developed. This paper presents development and testing of Bismuth Scandium Lead Titanate piezo ceramic transducers for high temperature SHM. These transducers are incorporated into a stretchable network system and mounted on a glass backing. Functionality is tested using a commercially available data acquisition system designed for SHM and intended for use with PZT transducers. Ongoing development of temperature compensation algorithms is also presented herein.

Reusable piezoelectric transducer for structural health monitoring using both Lamb wave and electromechanical impedance modes

2020 ◽  
Vol 31 (16) ◽  
pp. 1898-1909
Author(s):  
Qijian Liu ◽  
Yuan Chai ◽  
Xinlin Qing
Keyword(s):  
Structural Health Monitoring ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Lamb Wave ◽  
Lead Zirconate ◽  
Aluminum Plate ◽  
Electromechanical Impedance ◽  
Structural Health ◽  
Zirconate Titanate ◽  
Piezoelectric Lead Zirconate Titanate

A variety of structural health monitoring techniques have been developed to support the efficient online monitoring of structural integrity. Moreover, Lamb wave and electromechanical impedance methods are increasingly used for structural health monitoring applications due to their high sensitivity and effectiveness in detecting damage. However, these techniques require transducers to be permanently attached to structures because of the usage of baselines recorded under the condition without damage. In this study, a reusable piezoelectric lead zirconate titanate transducer for monitoring corrosion damage on the aluminum plate is introduced, which can be removed from the test specimen and reused with the repeatability of signals. The reusable piezoelectric lead zirconate titanate transducer is bonded on the aluminum plate using the ethylene-acrylic acid copolymer with an aluminum enclosure. A series of experiments are conducted on an aluminum plate, including the investigation for repeatability of signals and the capability of corrosion detection of the designed piezoelectric lead zirconate titanate transducer through the Lamb wave and electromechanical impedance methods. The simulated corrosion defect with the area of 15 × 15 mm2 is detected during experiments. The experimental results confirm that the reusable piezoelectric lead zirconate titanate transducer can effectively evaluate the corrosion damage to plate structure and can be reused many times.

scholarly journals A New Structural Health Monitoring Strategy Based on PZT Sensors and Convolutional Neural Network

2018 ◽  
Author(s):  
Mario A. de Oliveira ◽  
Andre V. Monteiro ◽  
Jozue Vieira Filho
Keyword(s):  
Neural Network ◽  
Structural Health Monitoring ◽  
Convolutional Neural Network ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Lead Zirconate ◽  
Industrial Applications ◽  
Electromechanical Impedance ◽  
Structural Health

Preliminaries Convolutional Neural Network (CNN) applications have recently emerged in Structural Health Monitoring (SHM) systems focusing mostly on vibration analysis. However, the SHM literature shows clearly that there is a lack of application regarding the combination of PZT (Lead Zirconate Titanate) based method and CNN. Likewise, applications using CNN along with the Electromechanical Impedance (EMI) technique applied to SHM systems are rare. To encourage this combination, an innovative SHM solution through the combination of the EMI-PZT and CNN is presented here. To accomplish this, the EMI signature is split into several parts followed by computing the Euclidean distances among them to form a RGB (red, green and blue) frame. As a result, we introduce a dataset formed from the EMI-PZT signals of 720 frames, encompassing a total of 4 types of structural conditions for each PZT. In a case study, the CNN-based method was experimentally evaluated using three PZTs glued onto an aluminum plate. The results reveal an effective pattern classification; yielding a 100% hit rate which outperforms other SHM approaches. Furthermore, the method needs only a small dataset for training the CNN, providing several advantages for industrial applications.

Sign in / Sign up

Export Citation Format

Share Document