scholarly journals MWCNT-Epoxy Nanocomposite Sensors for Structural Health Monitoring

2018 ◽  
Author(s):  
Omid Sam-DaIiri ◽  
Lisa-Marie Faller ◽  
Mohammadreza Farahani ◽  
Ali Roshanghias ◽  
Hannes Oberlercher ◽  
...  
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Impedance Measurement ◽  
Building Structures ◽  
Adhesive Bonds ◽  
Multi Wall Carbon Nanotubes ◽  
Structural Health ◽  
Nanocomposite Sensors ◽  
Parallel Resistance ◽  
Alternating Voltage

We address Multi-Wall Carbon NanoTubes (MWCNTs) for structural health monitoring in adhesive bonds such as in building structures. MWCNT-loaded composites are employed to sense strain changes under tension load using an AC impedance measurement setup. Different weight percentages of 1, 1.5, 2 and 3 wt.% MWCNT are added to the base epoxy resin using different dispersion times, i.e. 5, 10 and 15 minutes. The equivalent parallel resistance of the specimens is measured by applying an alternating voltage at different frequencies. To determine the mechanical as well as sensory properties, the specimens are subjected to a tensile test with concurrent impedance measurement. Using alternating voltage, a higher sensitivity of the impedance reading can be achieved. Employing these sensors in buildings and combining the readings of a network of such devices can significantly improve the buildings’ safety. Additionally, networks of such sensors can be used to identify necessary maintenance actions and locations.   

scholarly journals MWCNT–Epoxy Nanocomposite Sensors for Structural Health Monitoring

Electronics ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 143 ◽  
Author(s):  
Omid Sam-Daliri ◽  
Lisa-Marie Faller ◽  
Mohammadreza Farahani ◽  
Ali Roshanghias ◽  
Hannes Oberlercher ◽  
...  
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Impedance Measurement ◽  
Building Structures ◽  
Adhesive Bonds ◽  
Structural Health ◽  
Multi Walled Carbon Nanotubes ◽  
Nanocomposite Sensors ◽  
Walled Carbon Nanotubes ◽  
Alternating Voltage

We address multi-walled carbon nanotubes (MWCNTs) for structural health monitoring in adhesive bonds, such as in building structures. MWCNT-loaded composites are employed to sense strain changes under tension load using an AC impedance measurement setup. Different weight percentages of 1, 1.5, 2 and 3 wt % MWCNTs are added to the base epoxy resin using different dispersion times, i.e., 5, 10, and 15 min. The equivalent parallel resistance of the specimens is first measured by applying an alternating voltage at different frequencies. To determine the mechanical as well as sensory properties, the specimens are then subjected to a tensile test with concurrent impedance measurement at a fixed pre-chosen frequency. Using alternating voltage, a higher sensitivity of the impedance reading can be achieved. Employing these sensors in buildings and combining the readings of a network of such devices can significantly improve the buildings’ safety. Additionally, networks of such sensors can be used to identify necessary maintenance actions and locations.

Blockchain-Enabled Internet of Things for Unsupervised Structural Health Monitoring in Potential Building Structures

2021 ◽  
pp. 158-170
Author(s):  
Wael Mohammad Alenazy
Keyword(s):  
Artificial Intelligence ◽  
Decision Making ◽  
Structural Health Monitoring ◽  
Internet Of Things ◽  
Health Monitoring ◽  
Remote Monitoring ◽  
Building Structures ◽  
Stress Strain ◽  
Structural Health ◽  
Automated Decision Making

The integration of internet of things, artificial intelligence, and blockchain enabled the monitoring of structural health with unattended and automated means. Remote monitoring mandates intelligent automated decision-making capability, which is still absent in present solutions. The proposed solution in this chapter contemplates the architecture of smart sensors, customized for individual structures, to regulate the monitoring of structural health through stress, strain, and bolted joints looseness. Long range sensors are deployed for transmitting the messages a longer distance than existing techniques. From the simulated results, different sensors record the monitoring information and transmit to the blockchain platform in terms of pressure points, temperature, pre-tension force, and the architecture deems the criticality of transactions. Blockchain platform will also be responsible for storage and accessibility of information from a decentralized medium, automation, and security.

Wireless Structural Health Monitoring Using MEMS

2005 ◽  
Vol 293-294 ◽  
pp. 625-634 ◽  
Author(s):  
Markus Krüger ◽  
Christian U. Grosse ◽  
Pedro José Marrón
Keyword(s):  
Structural Health Monitoring ◽  
Monitoring System ◽  
Health Monitoring ◽  
Visual Inspection ◽  
Microelectromechanical Systems ◽  
Life Time ◽  
Building Structures ◽  
Wireless Monitoring ◽  
Structural Health ◽  
Reliability And Robustness

So far, the inspection of building structures and especially of bridges is mainly done visually. Therefore, the condition of the structure is examined from the surface and the interpretation and assessment is based on the experience of the expert. However, the main purpose of monitoring civil structures is not to substitute visual inspection. Continuous structural health monitoring should provide data from the inside of a structure to better understand its structural performance and to predict its durability and remaining life time. Monitoring should render objective data and observable alterations in the structure continuously, which cannot be done by visual inspection. More detailed information is needed with respect to different exposure due to dynamic and static loads and also temperature and moisture. Today mainly wired monitoring systems are used to monitor structures, which are relatively expensive and time consuming to install. In this paper the basic principle of a wireless monitoring system equipped with MEMS sensors is presented, which can be easily installed at different structures. Microelectromechanical systems (MEMS) are small integrated devices or systems that combine electrical and mechanical components. A wireless monitoring sensor network equipped with such MEMS could be produced with a very low budget and becomes very efficient. This permits a wide area of applications not only in civil engineering. With respect to different applications relevant properties of a wireless monitoring system are described. In detail network configuration, power consumption, data acquisition and data aggregation, signal analysis and data reduction as well as reliability and robustness are discussed.

New Directions of Health Monitoring for Building Structures

2016 ◽  
Vol 101 ◽  
pp. 15-19
Author(s):  
Akira Nishitani ◽  
Ping Xiang ◽  
Shohei Marutani ◽  
Tomohiko Hatada ◽  
Ryuta Katamura
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Building Structures ◽  
Structural Health ◽  
Displacement Sensors ◽  
New Directions ◽  
Story Drift ◽  
Direct Sensing ◽  
Structural Engineers

The concept of structural health monitoring (SHM) has appealed the attentions of structural engineers. However, most of the proposed schemes for SHM do not seem “friendly” to the practicing engineers in terms of the used data or employed methods. In this regard, the direct sensing of inter-story drift displacements could open the door to the construction of “practicing engineers friendly” SHM schemes. The authors‘ group developed non-contact types of inter-story drift displacement sensors. Several schemes based on the drift displacement sensing are discussed, which do not involve heavy researchers-oriented processes.

scholarly journals Damage Localization in a Building Structure during Seismic Excitation

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Jesús Morales-Valdez ◽  
Luis Alvarez-Icaza ◽  
José A. Escobar
Keyword(s):  
Structural Health Monitoring ◽  
Real Time ◽  
Health Monitoring ◽  
Damage Assessment ◽  
Early Stage ◽  
Detection Methods ◽  
Identification System ◽  
Building Structures ◽  
Simple Method ◽  
Structural Health

Aging of buildings during their service life has attracted the attention of researchers on structural health monitoring (SHM). This paper is related with detecting damage in building structures at the earliest possible stage during seismic activity to facilitate decision-making on evacuation before physical inspection is possible. For this, a simple method for damage assessment is introduced to identify the damage story of multistory buildings from acceleration measurements under a wave propagation approach. In this work, damage is assumed as reduction in shear wave velocities and changes in damping ratios that are directly related with stiffness loss. Most damage detection methods are off-line processes; this is not the case with this method. First, a real-time identification system is introduced to estimate the current parameters to be compared with nominal values to detect any changes in the characteristics that may indicate damage in the building. In addition, this identification system is robust to constant disturbances and measurement noise. The time needed to complete parameter identification is shorter compared to the typically wave method, and the damage assessment can keep up with the data flow in real time. Finally, using a robust threshold, postprocess of the compared signal is performed to find the location of the possible damage. The performance of the proposed method is demonstrated through experiments on a reduced-scale five-story building, showing the ability of the proposed method to improve early stage structural health monitoring.

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