A PZT-based electromechanical impedance method for monitoring the moisture content of wood

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Quan Zhai ◽  
Jicheng Zhang ◽  
Guofeng Du ◽  
Yulong Rao ◽  
Xiaoyu Liu
Keyword(s):  
Moisture Content ◽  
Mechanical Impedance ◽  
Impedance Method ◽  
Impedance Change ◽  
Monitoring Method ◽  
Content Type ◽  
Electromechanical Impedance ◽  
Wide Range ◽  
Impedance Technique ◽  
Piezoelectric Impedance

Purpose At present, piezoelectric impedance technology has been used in the study of wood damage monitoring. However, little effort has been made in the research on the application of piezoelectric impedance system to monitor the change of wood moisture content (MC). The monitoring method of wood MC is used by piezoelectric impedance technique in this study. Design/methodology/approach One piezoceramic transducer is bonded to the surface of wood specimens. The MC of the wood specimens increases gradually from 0% to 60% with 10% increments; the mechanical impedance of the wood specimen will change, and the change in the mechanical impedance of the structure is reflected by monitoring the change in the electrical impedance of lead zirconate titanate. Therefore, this paper investigates the relationship between wood MC change and piezoelectric impedance change to verify the feasibility of the piezoelectric impedance method for monitoring wood MC change. Findings The experiment verified that the real part of impedance of the wood increased with the increase of wood MC. Besides, the damage index root mean square deviation is introduced to quantify the damage degree of wood under different MC. At the same time, the feasibility and validity of this experiment were verified from the side by finite element simulation. Finally, MC monitoring by piezoelectric impedance technique is feasible. Originality/value To the best of the authors’ knowledge, this work is the first to apply piezoelectric ceramics to the monitoring of wood MC, which provides a theoretical basis for the follow-up study of a wide range of wood components and even wood structure MC changes.

scholarly journals Finite Element Simulation of Electro-Mechanical Impedance Technique

2015 ◽  
Vol 1115 ◽  
pp. 539-542
Author(s):  
Kamyar Tahmasebpour ◽  
Meftah Hrairi ◽  
Mohd Sultan I.S. Dawood
Keyword(s):  
Finite Element ◽  
Piezoelectric Materials ◽  
Piezoelectric Element ◽  
Mechanical Impedance ◽  
Signal Frequency ◽  
Impedance Method ◽  
Electromechanical Impedance ◽  
Finite Element Software ◽  
Sensor Position ◽  
Impedance Technique

Electro-mechanical impedance method is emerging as an important and powerful technique for structural health monitoring (SHM). Active elements of the technique are Piezoelectric Wafer Active Sensor (PWAS) bonded on the structure. Modeling and simulation of PWAS and host structure play an important role in the SHM applications with PWAS. For decades finite element method has been extensively applied in the analysis of piezoelectric materials and structures. In this paper, piezoelectric element and a host metallic structure were modeled using Ansys finite element software to find the Electromechanical Impedance (EMI) according to the signal frequency. After that, the EMI signature of the beam was found for different position of the PWAS patch. The study shows that sensor position may directly control the EMI signature.

Non Destructive Evaluation Based on Impedance Method Using Embedded PZT Sensor

2009 ◽  
Vol 79-82 ◽  
pp. 35-38 ◽  
Author(s):  
Dong Yu Xu ◽  
Xin Cheng ◽  
Shi Feng Huang ◽  
Min Hua Jiang
Keyword(s):  
Structural Damage ◽  
Crack Depth ◽  
Impedance Method ◽  
Impedance Spectra ◽  
Electromechanical Impedance ◽  
Non Destructive Evaluation ◽  
Increasing Trend ◽  
Impedance Technique ◽  
Impedance Curve ◽  
Non Destructive

The structural damage of mortar caused by simulated crack was evaluated using embedded PZT sensor combining with dynamic electromechanical impedance technique. The influence of embedded PZT sensors layout on detecting structural damage induced by the simulated cracks was also investigated. The results indicate that with increasing the simulated crack depth, the impedance real part of PZT sensors shift leftwards accompanying with the appearance of new peaks in the spectra. When more simulated cracks occur, the shift of the impedance curve becomes more obvious, and the amounts of new peaks in the impedance spectra also increase. RMSD indices of the structures with PZT sensors embedded in them with different layout can show the structural incipient damage clearly. With increasing more simulated cracks in the mortar structures, RMSD values of the structures with different PZT sensors layout become larger, under the same depth, RMSD indices of the structures with PZT sensor embedded transversely and horizontally in them show the increasing trend.

Electromechanical Impedance Method for Damage Detection of Typical Joint on Jacket Platform

2018 ◽  
Author(s):  
Boying Zhang ◽  
Hamad Hameed ◽  
Yuxin Xu ◽  
Chonglin Zhang ◽  
Yong Bai
Keyword(s):  
Health Monitoring ◽  
Mechanical Impedance ◽  
Theoretical Background ◽  
Impedance Method ◽  
Laboratory Measurements ◽  
Direct Evaluation ◽  
Jacket Platform ◽  
Health Monitoring System ◽  
Electromechanical Impedance ◽  
Experimental Works

Health monitoring of welded structural joints is a very important factor of the engineering community. Electro-mechanical impedance (EMI) technique allows the direct evaluation of structural dynamics by evaluating its E/M impedance or admittance signatures. This paper first gives a brief introduction of the theoretical background on the described method. Then, the described EMI technique is applied to recognize the presence of damage by executing experimental works where the damage in the form of crack is simulated with an impedance analyzer at various distances. Four typical welded metallic joints on a jacket platform successfully produced submillimeter cracks under cyclic loading and root mean square deviation (RMSD) is used to evaluate the degree of crack damage. Finally, an outcome of laboratory measurements performed with developed structural health monitoring system based on the electromechanical impedance phenomenon is presented.

Monitoring of concrete curing using the electromechanical impedance technique: review and path forward

2019 ◽  
pp. 147592171989306 ◽  
Author(s):  
Yee Yan Lim ◽  
Scott T Smith ◽  
Ricardo Vasquez Padilla ◽  
Chee Kiong Soh
Keyword(s):  
State Of The Art ◽  
Research Field ◽  
Strength Development ◽  
Early Age ◽  
Remote Monitoring System ◽  
Electromechanical Impedance ◽  
Wide Range ◽  
Impedance Technique ◽  
Technology Modeling ◽  
Early Age Concrete

The ability to monitor the strength development of early-age concrete is an important capability in the laboratory and in the field. Accurate and reliable in situ measurements can inform the appropriate time for removal of formwork and loading of structural elements, as well as determination of batch quality. The piezoelectric-based electromechanical impedance technique is emerging as a viable option for such monitoring needs. The first research articles on the topic started to appear in 2005, and since then, the research field has advanced and has grown in popularity. This article therefore presents the first state-of-the-art review of the topic to date. In this article, existing research is reviewed and sorted into key themes while critical developments as well as knowledge gaps are identified. The topics addressed range from miniaturization of hardware, methods of installation, incorporation of wireless technology, modeling, data interpretation, signal processing, influence of curing, and environmental conditions to a wide range of other practical issues. Previous studies have indicated that the electromechanical impedance technique has the potential to be developed into an autonomous and remote monitoring system, capable of predicting the strength development of early-age concrete structures in real time. An end game is therefore the realization of this capability. Appropriate comments are therefore also provided in this article about this goal. Researchers interested in venturing into this research area shall find this article a useful introduction as well as a state-of-the-art assessment. In addition, the identified research gaps can inform projects for more experienced research teams.

scholarly journals Piezoelectric Electro-Mechanical Impedance (EMI) Based Structural Crack Monitoring

2020 ◽  
Vol 10 (13) ◽  
pp. 4648 ◽  
Author(s):  
Tao Wang ◽  
Bohai Tan ◽  
Mingge Lu ◽  
Zheng Zhang ◽  
Guangtao Lu
Keyword(s):  
Resonance Frequency ◽  
Signal To Noise Ratio ◽  
Mechanical Impedance ◽  
Peak Frequency ◽  
Crack Size ◽  
Impedance Method ◽  
Small Scale ◽  
Element Simulation ◽  
Piezoelectric Impedance ◽  
Good Repeatability

To detect small cracks in plate like structures, the high frequency characteristics of local dynamics were studied with the piezoelectric electro-mechanical impedance (EMI) method, and damages were monitored by the changes of the EMI. The finite element simulation model of EMI was established, and numerical analysis was conducted. The simulation results indicated that the peak frequency of the piezoelectric admittance signal is a certain order resonance frequency of the structure, and the piezoelectric impedance method could effectively detect the dynamic characteristics of the structure. The piezoelectric admittance simulation and experimental study of aluminum beams with different crack sizes were performed. Simulation and experimental results revealed that the peak admittance frequency decreases with the increase of crack size, and the higher resonance frequency is more sensitive to the small-scale damage. The proposed method has good repeatability and strong signal-to-noise ratio to monitor the occurrence and development of small-scale crack damage, and it has an important application prospect.

scholarly journals Structural Health Monitoring of Timber Using Electromechanical Impedance (EMI) Technique

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Han ◽  
Quanjing Zhang ◽  
Chengfeng Wang ◽  
Guangtao Lu ◽  
Jinwei Jiang
Keyword(s):  
Lead Zirconate Titanate ◽  
Low Cost ◽  
Damage Index ◽  
Stress Waves ◽  
Impedance Method ◽  
Size Factor ◽  
Location Factor ◽  
Electromechanical Impedance ◽  
Damage Location ◽  
Impedance Technique

Nowadays, the electromechanical impedance method has been widely used in the field of structural healthy monitoring, especially for the concrete and steel materials. However, the electromechanical impedance studies on damage detection for timber are limited due to the anisotropic and ununiform biomaterial properties. As a low-cost and environment-friendly building material, timber has been widely used in the construction. Thus, it is beneficial to develop electromechanical impedance technique for structural healthy monitoring of timber so as to ensure the stability and safety of the entire timber structures. In this paper, two damage factors, i.e., the damage location factor and the damage size factor of timber specimens are investigated by using the electromechanical impedance method. The method is implemented by using a patch of Lead Zirconate Titanate transducer both as an actuator to generate stress waves and a sensor to detect stress waves after propagating across the timber specimens. Then, the damage index-root mean square deviation is employed to evaluate the damage severity of the timber specimens. The results indicate that the damage index changes consistently with the change of damage location and size factors, and the proposed method using electromechanical impedance technique can efficiently estimate the damage and its severity.

Sustainable dyeing of selected natural and synthetic fabrics using waste teak leaves (Tectona Grandis L.)

2020 ◽  
Vol 24 (4) ◽  
pp. 357-374
Author(s):  
Akshita Agrawal ◽  
Sheetal Chopra
Keyword(s):  
Moisture Content ◽  
Tectona Grandis ◽  
Waste Utilization ◽  
Ash Content ◽  
Test Method ◽  
Fastness Properties ◽  
Light Fastness ◽  
Content Type ◽  
Wide Range ◽  
Natural And Synthetic

Purpose This paper aims to extract the dye colourant from teak leaves using different aqueous mediums (Alkaline, Neutral and Acidic); to characterize the dye in terms of yield %; ash content and moisture content; to standardize the conditions of application of dye extracted from teak leaves on selected natural and synthetic fabrics using selected natural and chemical mordants; to assess the colour value (K/S, L*, c*/ h*, a*, b*) and fastness properties of the dyed samples in terms of wash, rub, light and perspiration fastness; and to develop dyed and printed designs using combinations of mordant and extracted dye. Design/methodology/approach Stage 1 – Extraction of dye from teak leaves; and characterization of dye: yield% ash content and moisture content. Stage 2 – Preparation of fabrics for dyeing; optimization of mordanting parameters using pre mordanting method followed by post mordanting; and optimization of dyeing parameters. Stage 3 – Testing of dyed fabric – Colour Measurement; K/S L*a*b*/L*c*h*; fastness properties; wash fastness done in the Laundrometer using ISO 2 standard test method; crock fastness done by Crockmeter using AATCC 116–1995 test method; perspiration fastness tested by perspirometer using AATCC 15– 2007 test method; and light fastness assessment in Mercury Bulb Tungsten Filament (MBTF) light fastness tester using AATCC Test Method 16–2004. Findings The findings of the study show that waste teak leaves can be used as an effective dye for natural as well as synthetic fabrics giving a wide range of colours on wool, silk and nylon. The maximum relative colour strength of the extracted dye on unmordanted dyed samples was found to be at pH 5 on wool and silk and at pH 7 on nylon. A range of shades was obtained with the use of different mordants. The extracted dye showed moderate to good fastness properties in terms of light, wash, rub and perspiration on wool and silk and excellent on nylon. Fastness properties were found to improve with the application of mordants both as pre and post method. Various combinations of mordants and dye result in obtaining pleasing and harmonious colours which were used aesthetically for printing. Research limitations/implications Due to time constrains, extraction in an organic medium could not be done, which could be a further scope for study. Practical implications Dyeing using teak leaves is a step towards sustainability and effective waste utilization with promising potential for application on natural as well as synthetic fabrics. Good colour with added properties will provide excellent solutions for eco-friendly methods of dyeing. Social implications This paper demonstrates the new possibilities offered by innovative uses of by-products of the timber industry and open good prospects for alternatives to synthetic colourants and new markets for the textile industry. It offers a new tool for the development of slow fashion. Originality/value It is a common practice to prune the tree branches to improve wood quality; thus, leaves are easily available as by product from pruning and also from wood harvesting. In the present study, waste teak leaves (Tectona grandis L.) were used for the extraction of dye.

scholarly journals Modeling, Simulation, Experimentation, and Compensation of Temperature Effect in Impedance-Based SHM Systems Applied to Steel Pipes

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2802 ◽  
Author(s):  
Rothschild A. Antunes ◽  
Nicolás E. Cortez ◽  
Bárbara M. Gianesini ◽  
Jozue Vieira Filho
Keyword(s):  
Temperature Effect ◽  
Petroleum Industry ◽  
Experimental Results ◽  
Temperature Changes ◽  
Steel Pipes ◽  
Electromechanical Impedance ◽  
Wide Range ◽  
Impedance Technique ◽  
Complete Study ◽  
Chemical Products

Pipelines have been widely used for the transportation of chemical products, mainly those related to the petroleum industry. Damage in such pipelines can produce leakage with unpredictable consequences to the environment. There are different structural health monitoring (SHM) systems such as Lamb wave, comparative vacuum, acoustic emission, etc. for monitoring such structures. However, those based on piezoelectric sensors and electromechanical impedance technique (EMI) measurements are simple and efficient, and have been applied in a wide range of structures, including pipes. A disadvantage of such technique is that temperature changes can lead to false diagnoses. To overcome this disadvantage, temperature variation compensation techniques are normally incorporated. Therefore, this work has developed a complete study applied to damage detection in pipelines, including an innovative technique for compensating the temperature effect in EMI-based SHM and the modeling of piezoceramics bonded to pipeline structures using finite elements. Experimental results were used to validate the model. Moreover, the compensation method was tested in two steel pipes—healthy and damaged—compensating the temperature effect ranging from −40 °C to +80 °C, with analysis on the frequency range from 5 kHz to 120 kHz. The simulated and experimental results showed that the studies effectively contribute to the SHM area, mainly to EMI-based techniques.

The Study on Piezoelectric Impedance Technique Used in Loading Damage Identification

2010 ◽  
Vol 139-141 ◽  
pp. 2612-2615 ◽  
Author(s):  
Jun Zhang ◽  
Zi Jian Qin
Keyword(s):  
Material Property ◽  
Health Monitoring ◽  
Damage Identification ◽  
Damage Index ◽  
Impedance Method ◽  
Frequency Range ◽  
Impedance Analyzer ◽  
Testing Frequency ◽  
Impedance Technique ◽  
Piezoelectric Impedance

The superiority and feasibility of piezoelectric impedance method used in damage detecting was expounded, and the research status of the technical was summarized. Then, the rationale of the basic theory of the technique used in damage identification and health monitoring was analyzed here. The experiment of the damage change of loaded beam was researched. The experiment of the beam which was loaded by a material property, the value of the beam was got by an impedance analyzer, while the beam with different pull force. The research indicates that while the testing frequency range should elect as 300k-800k, with the increasing of loading force, the value of real part impedance is descending, the damage index of beam is increasing. PZT can sensitively catch the influence brought by stress varying

Damage Detection Using Electromechanical Impedance Technique Combined with Scanning Laser Vibrometry

2013 ◽  
Vol 569-570 ◽  
pp. 687-694
Author(s):  
Szymon Opoka ◽  
Pawel Malinowski ◽  
Tomasz Wandowski ◽  
L. Skarbek ◽  
Wieslaw Ostachowicz
Keyword(s):  
Moisture Content ◽  
Damage Detection ◽  
Scanning Laser ◽  
Laser Vibrometry ◽  
Electromechanical Impedance ◽  
Impedance Technique ◽  
Vibrational Characteristics ◽  
Scanning Laser Vibrometry

The paper consists of two parts. First, Electromechanical Impedance (EMI) method is proven to be able to determine some vibrational characteristics of the investigated structure. In order to verify this statement, Scannig Laser Vibrometry (SLV) is used to correlate frequency peaks of velocity (or displacement) operational deflection shapes with corresponding ones obtained by EMI method. Finally, the influence of moisture content in CFRP sample on resonance peaks is investigated using EMI method. Damage detection indicator in this case is based on shifts of resonant peaks.

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