Research on Piezoelectric Based Sensing in Civil Engineering SHM

This research paper investigates the applications of piezoelectric based sensing techniques in structural health monitoring (SHM) within the field of civil engineering. The study focuses on the importance of monitoring the condition of buildings to detect potential damages that could lead to structural failure. The research explores the use of piezoelectric sensors for damage detection, employing experimental procedures and analysis on in-situ damage detection using frequency response and Lamb wave methods. The paper examines the sensor technology methods used for health monitoring, including a literature review covering the need for piezoelectric sensors in SHM, sensor technology methods for concrete structures, and repair detection methods in civil structures. The research aims to design a SHM system for civil engineering applications and analyzes the sensor functionality under extreme loading events, with objectives including the design of SHM, analysis of sensor methods, and study of damage detection methods. The paper also addresses key research questions concerning the usefulness of piezoelectric sensors, sensor technology methods, and the response of damage detection methods to frequency changes. The study highlights the significance of SHM in ensuring the safety and longevity of civil structures, emphasizing the role of piezoelectric materials in providing real-time information, detecting defects, and monitoring stress and temperature. The paper concludes by discussing the advantages and disadvantages of piezoelectric materials and their application in SHM systems, emphasizing the importance of wireless sensor networks for enhanced monitoring capabilities.

Running head: RESEARCH PAPER
Investigation on civil engineering applications of Piezoelectric based sensing techniques in
structural health monitoring
Name of the Student:
Name of the University:

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Abstract
Into the field of civil engineering, it is critically importance that condition of the buildings is
required to monitor for detecting of damages that is possible to failure of the civil structure. The
research is based on “Investigation on civil engineering applications of Piezoelectric based
sensing techniques in structural health monitoring”. Structural health monitoring is based on
capability of the system to detect and overcome with the structural damages of the buildings. In
this particular study, piezoelectric based sensing techniques are being used for detection of the
damages. The researcher performed of experimental procedures and did analysis on selected
research topic. The analysis is being performed with in-situ damage those are detecting the
materials with use of piezoelectric sensors. Two of the methods are used in this particular study
such as frequency response method and lamb wave method. Lamb wave methods are used to
handle of the location of the damages.
Keywords: Piezoelectric based sensing techniques, Structural health monitoring, Frequency
response method, Lamb wave method

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Table of Contents
1.0 Introduction................................................................................................................................3
2.0 Research Aims and Objectives..................................................................................................4
3.0 Research questions.....................................................................................................................5
4.0 Literature review........................................................................................................................5
4.1 Introduction............................................................................................................................5
4.2 Need of Piezoelectric Sensor in SHM (Structural Health Monitoring) in Civil Engineering
.....................................................................................................................................................7
4.3 Sensor Technology Methods that are used for Health Monitoring in Concrete Structures...9
4.4 Repair Detection Methods that are used in Civil Structures................................................11
5.0 Theoretical content or methods...............................................................................................13
6.0 Experimental set up.................................................................................................................16
7.0 Analysis, discussion and performance.....................................................................................17
8.0 Conclusion...............................................................................................................................19
References......................................................................................................................................21

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1.0 Introduction
Liu et al. (2017) stated that infrastructure of civil engineering is most expensive
nationwide investment and their structures have longer service life as evaluated to additional
commercial products. The prototypes into civil engineering and the structure is lead to innovative
in terms of design with construction. The important structure of civil engineering includes of
bridges, buildings and dams. Yaphary et al. (2017) demonstrated that the civil structures are
equipped with Structural Health Monitoring (SHM) for ensuring of structural integrity as well as
safety. SHM aims to develop of automated systems for monitoring, tear down inspection and
damage detection of the civil structures (Tao et al. 2016). SHM system provides real time
information, detects defects and monitoring of stress and temperature. It is required to monitor
for ensuring of safety and tough service life. SHM system consists of three components such as
sensor, data processing and health evaluation system. The first step to set up the system is to
integrate of level of consistent structural sensing ability.
Chopra, Nigam and Pandey (2015) cited that SHM system is based on civil structure
which allows remote monitoring with handling of automated system over inspection cycle to
reduce down time. The main focus of this paper is to replace of current cycle to inspect with
monitoring system which tends to increase damage probability before catastrophic failures
(Amezquita-Sanchez et al. 2014). Incidents such as collapse of building are rise into various
parts of the world with little warning before it occurs. Due to increase into total number of
building incidents, it becomes important to develop detection methods for reduction of buildings
damage. Wang, Paur and Ravikovitch (2017) mentioned that buildings as well as critical
infrastructure are being monitored such as patient into the hospital, signs for degradation,

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impeding disability and collapses. The sensors are used to maintain and know the current state of
the building structure and technologies to analyze its current situation. Grauer and Morelli
(2013) stated that intelligent sensors as well as technologies are used to diverse array of the data
and create of structural picture of the buildings that help to determine early detection of the
damage due to natural hazards.
2.0 Research Aims and Objectives
The aim of this paper is based on research for designing of SHM for the applications of
civil engineering. In this paper, it analyzed piezoelectric based sensing techniques for the civil
engineering structures such as buildings. The structural design of the building is based on various
sensing methods which hold of strengths and weakness to conduct of the building materials. It
uses of insulation materials with damage to fibers. The other aim is to analyze the sensor
functionality with the service time with extreme loading events. There are various effects that
provide consequence on wave’s propagation with change of measured impedance spectrum. This
research study is based on effects where both structure bonding as well as sensor is based on
techniques which consist of host structure to monitor the services. Different types of methods are
used for health monitoring of the buildings. The main aspect of this paper is to analyze
piezoelectric sensor for civil engineering applications.
Following are the objectives for this particular research study:
 To design of SHM for the applications of civil engineering
 To analyze the sensor technology methods used for health monitoring
 To study the damage detection methods able to respond to frequency change
method

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3.0 Research questions
Following are the questions which are required to analyze in this paper:
1. How are Piezo sensors useful for the SHM into civil engineering?
2. What are the sensor technology methods which could be used for health monitoring?
3. How are the damage detection methods able to respond to frequency change method?
4.0 Literature review
4.1 Introduction
The structures of Civil engineering have longer life of service and are very impossible to
change the structure or replace them once they are made. Yan et al. (2017) stated that the civil
structures that are built can deteriorate any time before they are expected to. The structures
mainly deteriorate because of overload, environmental erosion, inspection methods, aging,
maintenance lack, excessive use and many more. Civil engineering for SHM (Structural Health
Monitoring) system that is effective can diagnose the defects and location in real time (Hu, X.,
Zhu and Wang 2014).This can help to repair the structure and reinforce them in time so that the
safety and structural integrity can be ensured. Methods of SHM (Structural Health Monitoring)
systems are applied to structures of civil engineering and to their components at present time.
Banerji, Bagchi and Khazaeli (2016) argued that it includes static displacement, methods
of identification, testing and also non- destructive method of testing such as acoustic emission,
impedance, X-ray, pulse radar, thermal imaging and ultrasonic. The methods of Structural Health
Monitoring System are mostly qualitative and are difficult to carry out. Talakokula, Bhalla and
Gupta (2014) demonstrated that the materials that are smart include optical fiber sensor,

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intelligent composites that are cement based, materials of magneto astrictive and piezoelectric
materials. These methods are used to provide a new process that is long term and real time civil
engineering structures of health monitoring. According to Annamdas and Soh (2016) these
materials have sensing technology, driving and sensing function both together, and they can be
integrated with civil structure to build an intelligent structural system. Composition of the signal
processing, user interface, interpretation software of signal is all included in system of structural
health detection (Wymore et al. 2015). Out of all the materials, the piezoelectric material that are
represented by only piezoelectric ceramics have the most integrated driving and sensing
integration which make the SHM (Structural Health Monitoring) suitable to do all the processes.
The phenomenon of Piezoelectricity deals with changing mechanical energy to electrical
energy and also vice-versa. The material which possesses piezoelectricity generates electrical
charge after the application of mechanical pressure on that material. The vice-versa also happens
that when a material gets a geometric change when electric charge is applied on the material.
Banerji, Bagchi and Khazaeli (2016) stated the materials of piezoelectric include piezoelectric
ceramics, Piezoelectricity Ceramics, piezoelectricity polymers and Polymer composites are used
in piezoelectric actuators and the sensors of piezoelectric that are needed for SHM (Structural
Health Monitoring) and also for structural repair.
There is advantage sand disadvantages of each type of materials that are used in
piezoelectric (Zou et al. 2015).The advantages of piezoelectric materials are: Ceramics are very
less expensive and are more fabricated than the polymers. The ceramics have excellent
electromechanical coupling and have very high dielectric constants. They are very flexible and
are the polymer composites and ceramic of piezoelectric are considered to have superior
properties in comparison to materials of single phase (Leung et al. 2015). The disadvantages of

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piezoelectric are: The ceramics are brittle and stiff. The monolithic ceramics cannot be coated on
any curved surface which gives a limitation to the flexibility of design of the transducer. The
polymers of piezoelectric have less dielectric constant and very low electromechanical coupling.
The polymers and the ceramics of piezoelectric have impedance, intermediate dielectric constant
and very less spurious mode.
4.2 Need of Piezoelectric Sensor in SHM (Structural Health Monitoring) in Civil
Engineering
All civil infrastructures, industrial structures, residential buildings are the most common
concrete structures that are available now-a-days. Annamdas, Bhalla and Soh (2017) concluded
the life of all such concrete structures gets affected and constantly degraded by different factors
such as fatigue, natural disasters, aging and corrosion throughout their life. The degradation that
occurs to the structures reduces the disaster resistance ability of the structure and can also lead to
full collapse of the structure or may lead to partial failure of the concrete building (Zhang, Lie
and Xiang 2013). The safety of property and life of people faces the threat for such accidents if
occurs. To mitigate such threat that arrives in the structure, technology of health monitoring in
concrete structures is considered as the most important research areas in present days (Lim et al.
2017). Good results have been received from the transducers of piezo ceramic for health
monitoring in concrete structures. The SHM (Structural Health Monitoring) that are based on
piezoelectric are mainly classified into two categories: passive monitoring and active monitoring.
For methods of damage diagnosis, technology of active monitoring can further be divided into
two parts, stress wave based method and mechanical impedance wave based method.
The wave based method depends on the principle to use the sensing property of
piezoelectric ceramics so that the actuators that are sensor based are established in the inside

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structures (Basu et al. 2014). The diagnosis and the identification of the difference between the
current signal and the original signal are analyzed and scanned by this process. A new sensor
which is known as smart aggregate is embedded in the piezo ceramic patch inside a small block
of concrete that is same as the real aggregate that were previously used to monitor the concrete
structure’s health. Baptista et al. (2014) stated that with the new sensor aggregate, the cracks that
occur in the concrete structure can be detected and can be effective monitored with monitoring
methods that are sensor based. The method of mechanical impedance is used for monitoring the
local damage that occurs in the structure. This can be done by comparing the value of
mechanical impedance of a structure that is affected or damaged with a structure that is perfectly
healthy (Chopra, Nigam and Pandey 2015).
The technology of SHM (Structural Health Monitoring) that are traditional mainly uses
wired network for the collection of data. The traditional method of SHM had an advantage
ability of good anti interference. The disadvantage of the traditional methods of SHM is that the
system uses large amount of cables and also uses manpower (Talakokula, Bhalla and Gupta
2014). This increases the complexity of wiring and also increase the maintenance cost because
due to wiring, the number of nodes in the structure also increases. Some structures also may not
permit the use of cable surrounding the buildings for the traditional method of SHM. For making
the structure wireless, WSNs (Wireless Sensor Networks) can be applied to the SHM (Structure
health Monitoring) for making the structure secure and safe (Zou et al. 2015). The system of
WSN (Wireless Sensor Network) is much lower and the cost of maintenance is vey less. The
WSN (Wireless Sensor Network) boost the practical use of Structure Health Monitoring to a
large scale.

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4.3 Sensor Technology Methods that are used for Health Monitoring in Concrete
Structures
According to Di Sante (2015) some of the comprehensive methodologies that are
determined and located to extent the linear crack in plates, pipes and cracks that are developed
on flight time analysis. These are done mainly by data analysis methods which includes wavelet
transform. The applications where the sensor technology is used in detecting the health of
concrete structures are described as follows:
Beams- The data that are experimented to locate a crack in the aluminum beam are based
on consideration of wave propagation (Na and Baek 2017). Let the beam that is considered has a
length of 650 mm, depth of 6mm, 32 mm width having an elasticity of 73.1 GPa. The density of
the beam let be 2,790 kg/m3. Choosing the sensor that is fit for the structure is considered as a
very important part of SHM (Structural Health Monitoring). Conventional strain gauge and
piezoelectric sensor are attached with the beam at 300mm for comparing it with other structures
that are healthy. The signals that are collected are based on the impact force at 0.5mm and 200
mm and 1.0 mm deep (Annamdas and Soh 2016). The linear cracks that are at 450 mm are
mainly possessed using the wavelet transform. The second peak is detected by the piezoelectric
data where the data of strain gauge is non-existent.
The cracks that are deeper than 1mm, both of the sensors give a particular second peak.
The result that comes from the piezoelectric sensor is much more reliable and consistent than the
strain gauge for locating the damage and can be used anywhere it is needed. Talakokula and
Bhalla (2015) stated different boundaries of data are analyzed with three sets of data. This
includes fixed ended, cantilever conditions and simply supported. The gauges of conventional

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strain and the piezoelectric sensor are used to capture the wave signal that has the timings of
direct, boundary reflected waves and also reflects damage. These timings that are estimated by
technique of signal processing can deduce the damage location in the structure (Padiyar and
Balasubramaniam 2016). The results that are received from the experiment indicates the wavelet
transform that come from the dynamic response data from sensor of piezoelectric that is used to
locate the damage in beams.
Plates- According to Zheng (2015) the defects in plate structure, damage extent of the
crack, orientation and the location are to be identified by the sensor technology. A foci method is
proposed to detect such defects. To understand the concept, an ellipse is to be considered such as
PZT1 and PZT2. The foci of two ellipses are considered and the sum of distance from the foci of
the ellipse to the crack is constant and is made equal to the major diameter of the ellipse (Hu,
Zhu and Wang 2015). To get the exact position of crack from infinite solution that is provided by
an ellipse, signals from the sensor or actuator at different locations are to be used. This process
allows to construct more ellipse and the intersection will at last give the location of crack that is
estimated from the calculations. To get an unambiguous position of the crack, a minimum
number of three cracks are needed to do the calculations (Seshadrinath, Singh and Panigrahi
2014). When the position of the crack is estimated by intersecting three ellipses, the next method
is followed to determine the extent of the crack and the orientation of the crack.
The extent of the crack can be measured by using smaller tiny step shifts at both the ends.
To determine orientation of the crack, the foci of two ellipses is placed collinear with the crack
that is identified at two distinct positions (Talakokula and Bhalla 2015). The sensor location is
considered as C0S and the actuator location is considered as C0A along a line C0. Taking the
Snell’s Law and the Huygen’s Principle, the direction of that crack can be determined. This can

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be done by monitoring the cracks reflection peak’s energy in that area for all the lines at different
angles (Yan et al. 2017). After the determination of the orientation of the crack, the sensors and
actuators are shifted in positions that are parallel to right or left of the line C0 that was
considered. The Lamb wave is then actuated and spectrum of signal from sensor is also plotted.
The point when the energy peak vanishes from spectrum for the reflection from crack denotes
the end point of the crack.
Pipes- According to Yuen and Mu (2015) the cracks that are present in the homogeneous
pipes can be detected by this proposed methodology. The location, damage extent and the
orientation of the crack that occurs in the homogenous pipes can be determined. The attenuation
in strength of direct wave incidence of the sensor is observed to determine the crack of the pipe.
To interrogate the presence of the crack, four actuation positions on the pipe segment is needed.
The actuation position must be placed on two on each end of pipe segment. The circular sensor
and actuator of the piezoelectric method can be used to detect a crack in the pipe which is
experimentally proved. The proposed methodology of the piezoelectric actuator and sensor also
works for aluminum pipes (Zheng 2015). If the pipes are buried under sand, the sensor and the
actuators only helps to detect the cracks in the pipes. Experimentally it has been proved that this
proposed methodology is capable of detecting cracks that are concealed even when the pipes are
buried under the sand.
4.4 Repair Detection Methods that are used in Civil Structures
Different models are studied to repair the detection methods that are detected from the
piezoelectric materials. The models help to repair the structure that includes mechanical models
to repair the cracks or the beams that are delaminated or the cracks that are in the plate structures
under different load conditions (Yuen and Mu 2015). The size and the placement of piezoelectric