Printed Graphene-Based Strain Sensors for Structural Health Monitoring

Author(s):  
Long Wang ◽  
Kenneth J. Loh ◽  
Ramin Mousacohen ◽  
Wei-Hung Chiang

Strain sensors are one of the most widely used transducers for structural health monitoring, since strain can provide rich information regarding structural integrity. Recently, it has been shown that thin film sensors that incorporate nanomaterials can be engineered to possess unique properties, such as flexibility, high sensitivity, and distributed sensing capabilities, to name a few. To date, a plethora of different nanomaterials have been explored for fabricating strain sensors, such as by using conductive polymers, metal nanowires, and carbon nanotubes, among others. The aim of this work is to leverage the unique properties of graphene to fabricate next-generation thin film strain sensors. While graphene exhibits impressive mechanical and electrical properties, it remains challenging to harness these properties for sensing, primarily because of difficulties associated with high-quality synthesis and to incorporate them in a scalable fashion. In this study, few-layered graphene nano-sheets (GNS) were first synthesized using a low-cost, liquid-phase exfoliation technique. Second, GNS was dispersed in an aqueous solution with a low-concentration polymer acting as the dispersing agent. Third, the dispersion was printed onto flexible polymer substrates to form complex geometrical patterns, such as strain rosettes. Then, the electrical and electromechanical properties of the printed thin film sensors were characterized. It was found that the strain rosettes could resolve multi-axial strains applied during coupon tests. Overall, the GNS-based strain sensors showed excellent signal-to-noise ratio, stable sensing performance, high strain sensitivity, and remarkable reproducibility.

2021 ◽  
Vol 11 (4) ◽  
pp. 1647
Author(s):  
Georgios Foteinidis ◽  
Alkiviadis S. Paipetis

We report the transformation of a conventional composite material into a multifunctional structure able to provide information about its structural integrity. A purposely positioned grid of carbon fabric strips located within a glass fibre laminate in alternating 0/90 configuration combined with a ternary nanomodified epoxy matrix imparted structural health monitoring (SHM) topographic capabilities to the composite using the impedance spectroscopy (IS) technique. The matrix was reinforced with homogenously dispersed multi-walled carbon nanotubes (MWCNTs) and carbon black (CB). A sinusoidal electric field was applied locally over a frequency range from 1 Hz to 100 kHz between the junction points of the grid of carbon fabric strips. The proposed design enabled topographic damage assessment after a high-velocity impact via the local monitoring of the impedance. The data obtained from the IS measurements were depicted by magnitude and phase delay Bode plots and Nyquist plots. The impedance values were used to create a 2D and a multi-layer (3D) contour topographical image of the damaged area, which revealed crucial information about the structural integrity of the composite.


Respuestas ◽  
2016 ◽  
Vol 21 (1) ◽  
pp. 45 ◽  
Author(s):  
Daniel Alejandro Rodríguez-Caro ◽  
Enrique Vera-López ◽  
Helver Mauricio Muñoz-Barajas

Antecedentes: La protección catódica por corriente impresa es uno de los métodos para prevenir la corrosión de tuberías o tanques, preservando el estado estructural y la integridad del material. Para que un sistema de protección catódica funcione correctamente debe existir un control sobre las variables eléctricas que intervienen en el proceso, es por ello que se hace necesario monitorear variables tales como (Voltaje, Corriente y Potencial de protección). Objetivo: De esta manera se desarrolla un sistema de adquisición y monitoreo de datos en tiempo real, con el propósito de aumentar la accesibilidad a las variables eléctricas y de esta forma mejorar el funcionamiento del sistema de protección catódica. Métodos: El sistema de monitoreo y análisis de la información se basa en el concepto de SHM (Structural Health Monitoring), el cual consta de; un sistema electrónico de adquisición y envío remoto de señales (micro controlador y sistema GSM de comunicaciones) y un sistema de visualización y análisis de la información en un sistema móvil (celular), usando un servidor web para ello. Teniendo en cuenta que la condición de integridad estructural del ducto está determinada por el correcto funcionamiento del rectificador. Resultados: se logró implementar un sistema de monitoreo y visualización remota de las variables principales de un sistema de protección catódica. Se desarrolló un algoritmo basado en el concepto de SHM, el cual permite correlacionar, generar tendencia y establecer criterios de funcionamiento del sistema de protección catódica que permiten establecer si el sistema está asegurando la integridad estructural del ducto de transporte de crudo. Conclusión: lo novedoso del presente trabajo consiste en mostrar el comportamiento en tiempo real de las variables necesarias para analizar si el ducto está siendo correctamente protegido y generar las alarmas e informes sobre protección catódica, lo cual es la base del concepto de SHM (Structural Health Monitoring).AbstractBackground: Cathodic protection by impressed current is one of the methods to prevent corrosion of pipes or tanks, preserving the structural state and integrity of the material. For a cathodic protection system to function properly there must to be a control over the electrical variables involved in the process, which is why it is necessary to monitor variables such as (voltage, current and potential protection). Objective: to develop a system of data acquisition and monitoring in real time, in order to increase accessibility to electrical variables and thus improve the operation of the cathodic protection system. Methods: The monitoring and information analysis system is based on the concept of SHM (Structural Health Monitoring), which consists of an electronic system for remote acquisition and sending of signals (micro controller and GSM communications system) and a system for visualization and analysis of information in a mobile system (cell) using a web server for it. Given that the condition of structural integrity of the pipeline is determined by the correct operation of the rectifier. Results: It was possible to implement a monitoring and remote viewing system of the main variables of a cathodic protection system. An algorithm based on the concept of SHM was developed, allowing to correlate, generate trend and establish performance criteria for the cathodic protection system which allows to establish whether the system is ensuring the structural integrity of the crude transportation pipeline. Conclusion: the novelty of this work is to show the realtime behavior of the variables needed to analyze whether the pipeline is being properly protected and generate alarms and reports regarding cathodic protection, which is based on the concept of SHM (Structural Health Monitoring).Palabras Clave: corriente, corrosión, Innovación, monitoreo, SHM (Structural Health Monitoring)


2006 ◽  
Vol 83 (1) ◽  
pp. 139-148 ◽  
Author(s):  
W. D. NOTHWANG ◽  
S. G. HIRSCH ◽  
J. D. DEMAREE ◽  
C. W. HUBBARD ◽  
M. W. COLE ◽  
...  

Author(s):  
Christian Boller ◽  
Matthias Buderath

An overview of the aircraft design and maintenance process is given with specific emphasis on the fatigue design as well as the phenomenon of the ageing aircraft observed over the life cycle. The different measures taken to guarantee structural integrity along the maintenance process are addressed. The impact of structural health monitoring as a means of possibly revolutionizing the current aircraft structural monitoring and design process is emphasized and comparison is made to jet engines and helicopters, where health monitoring has already found the respective breakthrough.


2021 ◽  
Vol 09 (05) ◽  
pp. 512-527
Author(s):  
Raveendra Kiran ◽  
Kupparavalli Ramamurthy Prakash ◽  
Poorna Chandra ◽  
Venkatarayappa Ravi Kumar ◽  
Padubidere Bhaskara Asha ◽  
...  

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