scholarly journals A Feasibility Study on Timber Moisture Monitoring Using Piezoceramic Transducer-Enabled Active Sensing

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3100 ◽  
Author(s):  
Jicheng Zhang ◽  
Yong Li ◽  
Yongshui Huang ◽  
Jinwei Jiang ◽  
Siu-Chun Ho
Keyword(s):  
Moisture Content ◽  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Structural Damage ◽  
Wave Attenuation ◽  
Lead Zirconate ◽  
Active Sensing ◽  
Non Invasive ◽  
Potential Damage ◽  
Piezoceramic Transducer

In recent years, the piezoceramic transducer-enabled active sensing technique has been extensively applied to structural damage detection and health monitoring, in civil engineering. Being abundant and renewable, timber has been widely used as a building material in many countries. However, one of the more challenging applications of timber, in construction, is the potential damage caused by moisture. Increased moisture may cause easier warping of timber components and encourage corrosion of integrated metal members, on top of potentially causing rot and decay. However, despite numerous efforts to inspect and monitor the moisture content of timber, there lacks a method that can provide truly real time, quantitative, and non-invasive measurement of timber moisture. Thus, the research presented in this paper investigated the feasibility of moisture-content monitoring using an active sensing approach, as enabled by a pair of the Lead Zirconate Titanate (PZT) transducers bonded on the surface of a timber specimen. Using a pair of transducers in an active sensing scheme, one patch generated a designed stress wave, while another patch received the signal. While the active sensing was active, the moisture content of the timber specimen was gradually increased from 0% to 60% with 10% increments. The material properties of the timber correspondingly changed under varying timber moisture content, resulting in a measurable differential in stress wave attenuation rates among the different specimens used. The experimental results indicated that the received signal energy and the moisture content of the timber specimens show a parabolic relationship. Finally, the feasibility and reliability of the presented method, for monitoring timber moisture content, are discussed.

scholarly journals Detecting Debonding between Steel Beam and Reinforcing CFRP Plate Using Active Sensing with Removable PZT-Based Transducers

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 41 ◽  
Author(s):  
Jian Jiang ◽  
Jinwei Jiang ◽  
Xiaowei Deng ◽  
Zifeng Deng
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Wavelet Packet ◽  
Experimental Studies ◽  
Steel Structure ◽  
Steel Structures ◽  
Lead Zirconate ◽  
Steel Beam ◽  
Active Sensing ◽  
Cfrp Plate

Carbon fiber reinforced polymer (CFRP) plates are widely used to retrofit or reinforce steel structures, and the debonding damage between the steel structure and the CFRP plate is a typical failure in strengthening steel structures. This paper proposes a new approach to detecting debonding between a steel beam and a reinforcing CFRP plate by using removable lead zirconate titanate (PZT)-based transducers and active sensing. The removable PZT-based transducers are used to implement the active sensing approach, in which one transducer, as an actuator, is used to generate stress wave, and another transducer, as a sensor, is used to detect the stress wave that propagates across the bonding between the steel beam and the reinforcing CFRP plate. The bonding condition significantly influences the received sensor signal, and a wavelet-packet-based energy index (WPEI) is used to quantify the energy of the received signal to evaluate the severity of debonding between the steel beam and the reinforcing CFRP plate. To validate the proposed approach, experimental studies were performed, and two removable PZT-based transducers were designed and fabricated to detect the debonding between a steel beam and the reinforcing CRFP plate. The experimental results demonstrate the feasibility of the proposed method in detecting the debonding between a steel beam and the reinforcing CFRP plate using removable PZT-based transducers.

scholarly journals Monitoring bond-slip behavior of CFRP-RCESC beams using piezoelectric active sensing method

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Tianyong Jiang ◽  
Donghai Yu ◽  
Min Xiao ◽  
Lingyun Li ◽  
Lei Wang
Keyword(s):  
Reinforced Concrete ◽  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Wavelet Packet ◽  
Lead Zirconate ◽  
Active Sensing ◽  
Bond Slip ◽  
Damage States ◽  
Damage Process ◽  
As Stress

AbstractCombination of carbon fiber reinforced polymer (CFRP) tendon and reinforced concrete encased steel composite (RCESC) beam can improve the workability and the energy dissipation capacity of members. In this paper, three RCESC beams reinforced with steel bars or CFRP bars were designed and fabricated to study the bond-slip behavior between I-shaped steel and CFRP reinforced concrete and the damage states between bond-slip interfaces of the beams. The lead zirconate titanate (PZT) patch as stress wave actuator, the smart aggregates (SAs) were installed in concrete as the sensors to collect the stress wave signal. A method based on piezoelectric active sensing was developed to monitor the bond-slip damage of CFRP-RCESC beam. The changes of responding signals were characterized in time- and frequency- domains. The characteristic information of bond-slip damage was further quantified by wavelet packet energy. Results show the bond-slip resistance of the CFRP-RCESC beams can be improved by increasing reinforcement ratio and elastic modulus of the main bars. The bond-slip damage process of the specimens can be effectively monitored by the active sensing method.

scholarly journals A PZT-Based Electromechanical Impedance Method for Monitoring the Soil Freeze–Thaw Process

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1107 ◽  
Author(s):  
Jicheng Zhang ◽  
Chuan Zhang ◽  
Jiahao Xiao ◽  
Jinwei Jiang
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Soil Freezing ◽  
Impedance Method ◽  
Active Sensing ◽  
Freezing And Thawing ◽  
Engineering Structures ◽  
Electromechanical Impedance ◽  
Freeze Thaw ◽  
Wave Signal

It is important to conduct research on the soil freeze–thaw process because concurrent adverse effects always occur during this process and can cause serious damage to engineering structures. In this paper, the variation of the impedance signature and the stress wave signal at different temperatures was monitored by using Lead Zirconate Titanate (PZT) transducers through the electromechanical impedance (EMI) method and the active sensing method. Three piezoceramic-based smart aggregates were used in this research. Among them, two smart aggregates were used for the active sensing method, through which one works as an actuator to emit the stress wave signal and the other one works as a sensor to receive the signal. In addition, another smart aggregate was employed for the EMI testing, in which it serves as both an actuator and a receiver to monitor the impedance signature. The trend of the impedance signature with variation of the temperature during the soil freeze–thaw process was obtained. Moreover, the relationship between the energy index of the stress wave signal and the soil temperature was established based on wavelet packet energy analysis. The results demonstrate that the piezoceramic-based electromechanical impedance method is reliable for monitoring the soil freezing and thawing process.

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.

Estimate buried metal pipe length using PZT detected stress wave reflection

2020 ◽  
pp. 1045389X2096605
Author(s):  
Chuan Xu ◽  
Mingzhang Luo ◽  
Chuang Hei ◽  
Gangbing Song
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Wave Reflection ◽  
Wavelet Denoising ◽  
Lead Zirconate ◽  
Time Interval ◽  
Pipe Length ◽  
Metal Pipe ◽  
Metal Pipes ◽  
Reflected Signal

A roadway guardrail, as the driver’s last safety barrier, is an important part of a transportation system. The buried depth of the metal pipe directly determines the bearing capacity of the guardrail during an impact. It is important to estimate the buried depth during the inspection of a guardrail system. In this paper, we proposed an original method by integrating wavelet denoising, multiple self-correlation analysis (MSA) and energy spectrum analysis (ESA) to estimate the length of buried metal pipe based on the stress wave reflection. The stress wave is initiated by an impact on the exposed end of the buried pipe and stress wave reflection is detected by a PZT (Lead Zirconate Titanate) transducer. To execute the proposed method, firstly, Wavelet denoising is used to process the reflected stress wave signal to improve the signal-to-noise ratio. Then, the MSA detects the major frequency of the reflected signal. At last, the ESA extracts the time interval between the reflected signal and the excitation signal with the help of Short Time Fourier Transform (STFT) that acquires the frequency band where the reflected signal is located. Experimental verifications were carried out, and two different lengths of buried metal pipes are selected to verify the feasibility of the proposed method. The experimental results indicate that the proposed method can accurately extract the length of buried metal pipes. The superiority of the proposed method over the traditional methods, such as Peak-Peak Discriminance (PPD) and Phase Analysis Method (PAM), is demonstrated by experimental comparative studies.

scholarly journals Prestress Monitoring of a Steel Strand in an Anchorage Connection Using Piezoceramic Transducers and Time Reversal Method

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4018 ◽  
Author(s):  
Xiaoyu Zhang ◽  
Liuyu Zhang ◽  
Laijun Liu ◽  
Linsheng Huo
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Time Reversal ◽  
Stress Wave Propagation ◽  
Suspension Bridges ◽  
Active Sensing ◽  
Sensors And Actuators ◽  
Anchorage System ◽  
Steel Strand ◽  
Peak Value

Steel strands are widely used in cable stay or suspension bridges. The safety and stability of steel strands are important issues during their operation period. Steel strand is subjected to various types of prestress loss which loosens the wedge anchorage system, negatively impacting the stability of the structure and even leading to severe accidents. In this paper, the authors propose a time reversal (TR) method to monitor the looseness status of the wedge anchorage system by using stress wave based active sensing. As a commonly used piezoceramic material, Lead Zirconate Titanate (PZT) with a strong piezoelectric effect is employed. In the proposed active sensing approach, PZT patches are used as sensors and actuators to monitor the steel strand looseness status. One PZT patch is bonded to the steel strand, one PZT patch is bonded to the wedges, and another PZT patch is bonded to the barrel. There are three different interfaces of the wedge anchorage system to monitor the steel strand looseness status. In the first method, the PZT patch on the steel strand is used as an actuator to generate a stress wave and the PZT patch on the wedge is used as a sensor to detect the propagated waves through the wedge anchorage system. In the second method, the PZT patch on the steel strand is used as an actuator to generate a stress wave and the PZT patch on the barrel is used as a sensor to detect the propagated waves through the wedge anchorage system. In the third method, the PZT patch on the wedges is used as an actuator to generate a stress wave and the PZT patches on the barrel is used as a sensor to detect the propagated waves through the wedge anchorage system, of which the looseness will directly impact the stress wave propagation. The TR method is utilized to analyze the transmitted signal between PZT patches through the wedge anchorage system. Compared with the peak values of the TR focused signals, it can be found that the peak value increases as the wedge anchorage system tightness increases. Therefore, the peak value of the TR focused signal can be used to monitor the tightness of the steel strand. In addition, the experimental results demonstrated the time reversal method’s reliability, sensitivity and anti-noise property.

scholarly journals Multi-Scale Stress Wave Simulation for Aggregates Segregation Detection of Concrete Core in Circular CFST Coupled with PZT Patches

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1223 ◽  
Author(s):  
Hongbing Chen ◽  
Bin Xu ◽  
Yilung Mo ◽  
Tianmin Zhou
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Coupling Effect ◽  
Wavelet Packet ◽  
Lead Zirconate ◽  
Stress Wave Propagation ◽  
Voltage Response ◽  
Concrete Aggregate ◽  
Concrete Core ◽  
Multi Scale

In this study, the numerical investigation of the detectability of concrete aggregate segregation in circular concrete-filled steel tubulars (CCFST) based on piezoelectric lead zirconate titanate (PZT) measurement is performed. The stress wave propagation in the concrete core of circular CCFST excited with a surface-mounted PZT actuator is studied with multi-scale and multi-physical field coupling analysis. The piezoelectric effect of PZT patches and its coupling effect with CFSTs are considered. Numerical concrete modeling technology is employed to construct the concrete core composed of randomly distributed aggregates with and without aggregate segregation at different levels, mortar, and an interfacial transition zone (ITZ). The effects of the random distribution of elliptical aggregates, aggregate segregation, and the existence of ITZ in the concrete core on the wave fields in the cross-section and the corresponding voltage response of the embedded PZT sensor are discussed. An evaluation index based on wavelet packet analysis on the output voltage response is defined, and its sensitivity to concrete aggregate segregation is systematically investigated. The multi-scale and multi-physics coupling simulation results indicate that concrete aggregate segregation in the concrete core of CFST members can be efficiently detected based on the stress wave measurement with a PZT sensor.

Structural Parameters Identification Using PZT Sensors and Genetic Algorithms

2009 ◽  
Vol 79-82 ◽  
pp. 63-66
Author(s):  
Yao Wen Yang ◽  
Ai Wei Miao
Keyword(s):  
Genetic Algorithms ◽  
Structural Properties ◽  
Lead Zirconate Titanate ◽  
Structural Damage ◽  
Structural Parameters ◽  
Excitation Frequency ◽  
Mechanical Impedance ◽  
Lead Zirconate ◽  
Physical Parameters ◽  
Optimal Values

Piezoelectric ceramic lead zirconate titanate (PZT) based electro-mechanical impedance (EMI) technique for structural health monitoring (SHM) has been successfully applied to various engineering systems [1-5]. In the traditional EMI method, statistical analysis methods such as root mean square deviation indices of the PZT electromechanical (EM) admittance are used as damage indicator, which is difficult to specify the effect of damage on structural properties. This paper proposes to use the genetic algorithms (GAs) to identify the structural parameters according to the changes in the PZT admittance signature. The basic principle is that structural damage, especially local damage, is typically related to changes in the structural physical parameters. Therefore, to recognize the changes of structural parameters is an effective way to assess the structural damage. Towards this goal, a model of driven point PZT EM admittance is established. In this model, the dynamic behavior of the structure is represented by a multiple degree of freedom (DOF) system. The EM admittance is formulated as a function of excitation frequency and the unknown structural parameters, i.e., the mass, stiffness and the damping coefficient of many single DOF elements. Using the GAs, the optimal values of structural parameters in the model can be back-calculated such that the EM admittance matches the target value. In practice, the target admittance is measured from experiments. In this paper, we use the calculated one as the target. For damage assessment, these optimal values obtained before and after the appearance of structural damage can be compared to study the effects of damage on the structural properties, which are specified to be stiffness and damping in this study. Furthermore, the identified structural parameters could be used to predict the remaining loading capacity of the structure, which serves the purpose for damage prognosis.

NONLINEAR ACOUSTIC TECHNIQUE FOR MONITORING POROSITY IN ADDITIVELY MANUFACTURED PARTS

2021 ◽  
pp. 1-17
Author(s):  
Sehyuk Park ◽  
Hamad N. Alnuaimi ◽  
Anna Hayes ◽  
Madison Sitkiewicz ◽  
Umar Amjad ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Lead Zirconate Titanate ◽  
Wave Attenuation ◽  
Signal Amplitude ◽  
Lead Zirconate ◽  
Ultrasonic Waves ◽  
Analysis Technique ◽  
Nonlinear Ultrasonic ◽  
Linear And Nonlinear ◽  
Characterization Of Materials

Abstract Ultrasonic wave based techniques are widely used for damage detection, and for quantitative and qualitative characterization of materials. In this study, ultrasonic waves are used for probing the response of additively manufactured 316L stainless steel samples as their porosity changes. The additively manufactured stainless steel specimens were fabricated using a laser powder bed fusion (LPBF) metal 3D printer. Four different levels of porosity were obtained by suitably controlling the LPBF process parameters. For generating ultrasonic waves, lead zirconate titanate (PZT) transducers were used. The signals were generated and propagated through the specimens in a transmission mode setup. Both linear and nonlinear analyses were used during the signal processing of the recorded signals for damage characterization. Linear ultrasonic parameters such as the time-of-flight (related to wave velocity) and signal amplitude (related to wave attenuation) were recorded. The nonlinear ultrasonic parameter, Sideband Peak Count - Index (SPC-I), was obtained by a newly developed nonlinear analysis technique called the SPC-I technique. Results obtained for the specimens were analyzed and compared for both linear and nonlinear ultrasonic analyses. Finally, the effectiveness of the SPC-I technique in monitoring porosity levels in additively manufactured specimens is discussed.

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