Journal articles: 'Smart structures; Distributed sensors'

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Martínez, Fernando, E. Tynan, M. Arregui, G. Obieta, and J. Aurrekoetxea. "Electroactive Pressure Sensors for Smart Structures." Advances in Science and Technology 56 (September 2008): 122–26. http://dx.doi.org/10.4028/www.scientific.net/ast.56.122.

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A hardware-software interface for smart electroactive pressure sensors has been designed with the objective of providing a low power consumption and high performance impact monitoring system, integrated in new smart structures. The interface is specifically designed for its use with distributed pressure sensors based on conductive polymers. Their low cost and flexibility make them suitable for placing on large surfaces. The smart sensor integrates a microprocessor, a radio chip and a complete analog front end based on a period-modulated oscillator. The software developed implements new interface applications for this hardware in TinyOS. The response of the sensor, both loading and unloading, to different impact energies first, and then to different probe stiffness is presented. The behaviour of the sensor to impact is also compared to the response in static, and the different factors affecting the sensor response in both conditions are described. Comparing and contrasting the sensor signal with that of an impact pendulum shows that the sensor is suitable for measuring impact in both flexible and rigid structures.

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Kim, Sang Hoon, Jung Ju Lee, Dae Cheol Seo, and Jeong Ok Lim. "Application of Point and Distributed Optical Fiber Sensors to Health Monitoring of Smart Structures." International Journal of Modern Physics B 17, no. 08n09 (2003): 1368–73. http://dx.doi.org/10.1142/s0217979203019010.

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Point optical fiber sensors are useful in the monitoring of localized structural damage, but a large number of the sensors must be multiplexed for large structure monitoring. On the other hand, distributed optical fiber sensors can obtain a continuous distribution of strain or temperature with one sensing fiber, and they are suitable for the large structure monitoring due to their measurement range reaching tens of kilometers. However, the distributed sensors have the spatial resolution of tens of centimeters to several meters, and they measure averaged strain or temperature. In this paper, the application results of transmission-type extrinsic Fabry-Perot interferometric (TEFPI) optical fiber sensors and Brillouin distributed optical fiber sensors to structural monitoring are presented. The TEFPI optical fiber sensors and Brillouin distributed sensors were applied to the fatigue damage monitoring of an aluminum plate patched with CFRP composite and the deflection monitoring of an alumimum-bending beam, respectively.

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Alwis, Lourdes S. M., Kort Bremer, and Bernhard Roth. "Fiber Optic Sensors Embedded in Textile-Reinforced Concrete for Smart Structural Health Monitoring: A Review." Sensors 21, no. 15 (2021): 4948. http://dx.doi.org/10.3390/s21154948.

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The last decade has seen rapid developments in the areas of carbon fiber technology, additive manufacturing technology, sensor engineering, i.e., wearables, and new structural reinforcement techniques. These developments, although from different areas, have collectively paved way for concrete structures with non-corrosive reinforcement and in-built sensors. Therefore, the purpose of this effort is to bridge the gap between civil engineering and sensor engineering communities through an overview on the up-to-date technological advances in both sectors, with a special focus on textile reinforced concrete embedded with fiber optic sensors. The introduction section highlights the importance of reducing the carbon footprint resulting from the building industry and how this could be effectively achieved by the use of state-of-the-art reinforcement techniques. Added to these benefits would be the implementations on infrastructure monitoring for the safe operation of structures through their entire lifespan by utilizing sensors, specifically, fiber optic sensors. The paper presents an extensive description on fiber optic sensor engineering that enables the incorporation of sensors into the reinforcement mechanism of a structure at its manufacturing stage, enabling effective monitoring and a wider range of capabilities when compared to conventional means of structural health monitoring. In future, these developments, when combined with artificial intelligence concepts, will lead to distributed sensor networks for smart monitoring applications, particularly enabling such distributed networks to be implemented/embedded at their manufacturing stage.

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Murayama, Hideaki, Kazuro Kageyama, Isamu Ohsawa, Makoto Kanai, Kiyhoshi Uzawa, and Tsuyoshi Matsuo. "Development of Smart Composite Panel with Optical Fiber Sensors." Key Engineering Materials 297-300 (November 2005): 659–64. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.659.

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We have developed a novel fiber-optic vibration sensors and applied commercially available strain and temperature sensors to health monitoring of composite structures. In this study, we constructed an optical fiber network integrating four types of optical fiber sensor into a carbon reinforced plastic (CFRP) panel. These four sensors were the vibration sensor developed by our laboratory, two distributed sensors based on Brillouin and Raman backscattering and Fiber Bragg Grating (FBG) sensors. By dealing the data obtained from the measurement systems corresponding to these four sensors, strain/stress and temperature distributions throughout the panel can be monitored. Vibration and elastic waves transmitting on the panel are also detected at several sensing points. Furthermore, we will be able to determine damage locations and modes by processing the wave signals. To make the panel with the optical fiber sensor network more sensitive and smarter, we are developing some techniques that can improve the performance of the sensors and can assess the structural integrity by analyzing measurement results. In this paper, the development of the first generation of our smart composite panel with the optical fiber sensors is described and the techniques making the panel more sensitive and smarter are also described.

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Tzou, H. S., and C. I. Tseng. "Distributed Modal Identification and Vibration Control of Continua: Piezoelectric Finite Element Formulation and Analysis." Journal of Dynamic Systems, Measurement, and Control 113, no. 3 (1991): 500–505. http://dx.doi.org/10.1115/1.2896438.

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“Smart” continua with integrated sensor/actuator for structural identification and control have drawn much attention in recent years due to the rapid development of high-performance “smart” structures. The continua are distributed and flexible in nature. Thus, distributed dynamic measurement and active vibration control are of importance to their high-demanding performance. In this paper, continua (shells or plates) integrated with distributed piezoelectric sensors and actuators are studied using a finite element technique. A new piezoelectric finite element with internal degrees of freedom is derived. Two control algorithms, namely, constant gain feedback control and Lyapunov control, are implemented. Structural identification and control of a plate model with distributed piezoelectric sensor/actuator is studied. Distributed modal voltage and control effectiveness of mono and biaxially polarized piezoelectric actuators are evaluated.

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Meoni, Andrea, Antonella D’Alessandro, Massimo Mancinelli, and Filippo Ubertini. "A Multichannel Strain Measurement Technique for Nanomodified Smart Cement-Based Sensors in Reinforced Concrete Structures." Sensors 21, no. 16 (2021): 5633. http://dx.doi.org/10.3390/s21165633.

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Nanomodified smart cement-based sensors are an emerging self-sensing technology for the structural health monitoring (SHM) of reinforced concrete (RC) structures. To date, several literature works demonstrated their strain-sensing capabilities, which make them suited for damage detection and localization. Despite the most recent technological improvements, a tailored measurement technique allowing feasible field implementations of smart cement-based sensors to concrete structures is still missing. In this regard, this paper proposes a multichannel measurement technique for retrieving strains from smart cement-based sensors embedded in RC structures using a distributed biphasic input. The experiments performed for its validation include the investigation on an RC beam with seven embedded sensors subjected to different types of static loading and a long-term monitoring application on an RC plate. Results demonstrate that the proposed technique is effective for retrieving time-stable simultaneous strain measurements from smart cement-based sensors, as well as for aiding the identification of the changes in their electrical outputs due to the influence of environmental effects variable over time. Accordingly, the proposed multichannel strain measurement technique represents a promising approach for performing feasible field implementations of smart cement-based sensors to concrete structures.

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KOSAKA, Tatsuro, and Nobuo TAKEDA. "Sensitivity Analysis of Modal Domain Distributed Fiber Optic Sensors for Smart Structures." Transactions of the Japan Society of Mechanical Engineers Series C 64, no. 618 (1998): 565–70. http://dx.doi.org/10.1299/kikaic.64.565.

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Chen, Xiyuan, Tanay Topac, Wyatt Smith, Purim Ladpli, Cheng Liu, and Fu-Kuo Chang. "Characterization of Distributed Microfabricated Strain Gauges on Stretchable Sensor Networks for Structural Applications." Sensors 18, no. 10 (2018): 3260. http://dx.doi.org/10.3390/s18103260.

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Smart structures mimic biological systems by using thousands of sensors serving as a nervous system analog. One approach to give structures this sensing ability is to develop a multifunctional sensor network. Previous work has demonstrated stretchable sensor networks consisting of temperature sensors and impact detectors for monitoring external environments and interacting with other objects. The objective of this work is to develop distributed, robust and reliable strain gauges for obtaining the strain distribution of a designated region on the target structure. Here, we report a stretchable network that has 27 rosette strain gauges, 6 resistive temperature devices and 8 piezoelectric transducers symmetrically distributed over an area of 150 × 150 mm to map and quantify multiple physical stimuli with a spatial resolution of 2.5 × 2.5 mm. We performed computational modeling of the network stretching process to improve measurement accuracy and conducted experimental characterizations of the microfabricated strain gauges to verify their gauge factor and temperature coefficient. Collectively, the results represent a robust and reliable sensing system that is able to generate a distributed strain profile of a common structure. The reported strain gauge network may find a wide range of applications in morphing wings, smart buildings, autonomous cars and intelligent robots.

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Wu, Bin-Yi, Xian-Sheng Qin, Shun-Qi Zhang, Jing Bai, Ting Xue, and Rüdiger Schmidt. "Unknown disturbance estimation for vibration systems using distributed piezoelectric sensors." Mechanics & Industry 19, no. 5 (2018): 506. http://dx.doi.org/10.1051/meca/2018042.

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Vibration is usually caused by external disturbances, which may lead to structural damage. Vibrations can be significantly suppressed by taking disturbances into account. However, in many cases disturbances are unknown or difficult to be measured directly. In order to estimate external unknown disturbances, this article develops a proportional-integral (PI) disturbance observer with measurement noises for smart structures using multiple distributed piezoelectric sensors. For simulation purpose, a dynamic finite element model of piezoelectric bonded smart structure is presented. This disturbance observation method is validated by estimating various kinds of unknown disturbances using piezoelectric measurements. Furthermore, the measurement numbers and the position of measurements are investigated.

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Jha, Akhilesh K., and Daniel J. Inman. "Sliding Mode Control of a Gossamer Structure Using Smart Materials." Journal of Vibration and Control 10, no. 8 (2004): 1199–220. http://dx.doi.org/10.1177/1077546304044796.

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Gossamer structures have been a subject of renewed interest for space applications because of their low weights, on-orbit deploying capabilities, and minimal stowage volumes. In this study, vibration suppression of an inflated structure using piezoelectric actuators and sensors has been attempted. These actuators and sensors can be suitably used for gossamer structures since they can conform to curved surfaces and provide distributed actuation and sensing capabilities. Using the natural frequencies and mode shapes of the system (structure, actuators, and sensors), a state-space model is derived. For designing a robust vibration controller, we used a sliding mode technique. The derivations of the sliding model controller and observer are presented in details. Finally, by means of numerical analysis, the method was demonstrated for an inflated torus considering Macro-Fiber Composite (MFC™) as actuators and Polyvinylidene Fluoride (PVDF) as sensors. The simulation studies show that the piezoelectric actuators and sensors are suitable for vibration suppression of an inflatable torus. The robustness properties of the controller and observer against the parameter uncertainty and disturbances are also studied.

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Huo, Linsheng, Hao Cheng, Qingzhao Kong, and Xuemin Chen. "Bond-Slip Monitoring of Concrete Structures Using Smart Sensors—A Review." Sensors 19, no. 5 (2019): 1231. http://dx.doi.org/10.3390/s19051231.

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Concrete structures with various reinforcements, such as steel bars, composite material tendons, and recently steel plates, are commonly used in civil infrastructures. When an external force overcomes the strength of the bond between the reinforcement and the concrete, bond-slip will occur, resulting in a relative displacement between the reinforcing materials and the concrete. Monitoring bond health plays an important role in guaranteeing structural safety. Recently, researchers have recognized the importance of bond-slip monitoring and performed many related investigations. In this paper, a state-of-the-art review on various smart sensors based on piezoelectric effect and fiber optic technology, as well as corresponding techniques for bond-slip monitoring is presented. Since piezoelectric sensors and fiber-optic sensors are widely used in bond-slip monitoring, their principles and relevant monitoring methods are also introduced in this paper. Particularly, the piezoelectric-based bond-slip monitoring methods including the active sensing method, the electro-mechanical impedance (EMI) method and the passive sensing using acoustic emission (AE) method, and the fiber-optic-based bond-slip detecting approaches including the fiber Bragg grating (FBG) and the distributed fiber optic sensing are highlighted. This paper provides guidance for practical applications and future development of bond-slip monitoring.

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Stroia, Nicoleta, Daniel Moga, Istvan Kovacs, Gabriela Mocanu, and Mirela Dobra. "Hydropower Structures Monitoring System with Hierarchically Distributed Smart Sensor Network." IFAC Proceedings Volumes 46, no. 6 (2013): 37–41. http://dx.doi.org/10.3182/20130522-3-ro-4035.00047.

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Jenkins, R. Brian, Peter Joyce, Adam Kong, and Charles Nelson. "Discerning Localized Thermal Heating from Mechanical Strain Using an Embedded Distributed Optical Fiber Sensor Network." Sensors 20, no. 9 (2020): 2583. http://dx.doi.org/10.3390/s20092583.

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Prior research has demonstrated that distributed optical fiber sensors (DOFS) based on Rayleigh scattering can be embedded in carbon fiber/epoxy composite structures to rapidly detect temperature changes approaching 1000 °C, such as would be experienced during a high energy laser strike. However, composite structures often experience mechanical strains that are also detected during DOFS interrogation. Hence, the combined temperature and strain response in the composite can interfere with rapid detection and measurement of a localized thermal impulse. In this research, initial testing has demonstrated the simultaneous response of the DOFS to both temperature and strain. An embedded DOFS network was designed and used to isolate and measure a localized thermal response of a carbon fiber/epoxy composite to a low energy laser strike under cyclic bending strain. The sensor interrogation scheme uses a simple signal processing technique to enhance the thermal response, while mitigating the strain response due to bending. While our ultimate goal is rapid detection of directed energy on the surface of the composite, the technique could be generalized to structural health monitoring of temperature sensitive components or smart structures.

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Hušek, Petr, Filip Svoboda, Martin Hromčík, and Zbyněk Šika. "Low-Complexity Decentralized Active Damping of One-Dimensional Structures." Shock and Vibration 2018 (December 2, 2018): 1–9. http://dx.doi.org/10.1155/2018/6421604.

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In the paper, we propose distributed feedback control laws for active damping of one-dimensional mechanical structures equipped with dense arrays of force actuators and position and velocity sensors. We consider proportional position and velocity feedback from the neighboring nodes with symmetric gains. Achievable control performance with respect to stability margin and damping ratio is discussed. Compared to full-featured complex controllers obtained by modern design methods like LQG, H-infinity, or mu-synthesis, these simplistic controllers are more suitable for experimental fine tuning and are less case-dependent, and they shall be easier to implement on the target future smart-material platforms.

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Narayanan, S., and V. Balamurugan. "Finite element modelling of piezolaminated smart structures for active vibration control with distributed sensors and actuators." Journal of Sound and Vibration 262, no. 3 (2003): 529–62. http://dx.doi.org/10.1016/s0022-460x(03)00110-x.

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Wan, Z., J. D. Li, M. Jia, and J. L. Li. "Structural Health Monitoring (SHM) of Three-Dimensional Braided Composite Material using Carbon Nanotube Thread Sensors." Journal of Mechanics 29, no. 4 (2013): 617–21. http://dx.doi.org/10.1017/jmech.2013.42.

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ABSTRACTStructural Health Monitoring (SHM) takes advantage of the recent advances in nanotechnology and sensing in order to monitor the behavior of a structure, assess its performance and identify damage at an early stage. Monitoring the state of strain throughout an entire structure is essential to determine its state of stress, detect potential residual stresses after fabrication, and also to help to establish its integrity. The Carbon nanotube thread was integrated into three-dimensional braiding materials and used for the first time as a sensor to monitor strain and also to detect damage in the three-dimensional braided composite material.In this paper a literature review about the application of carbon nanotubes thread for sensors and smart materials used for SHM of braiding structures is presented. The test data show the braided angle is important parameter for structural health monitoring of three-dimensional. The research will provide a new integrated and distributed technologies for the built-in carbon nanotube sensor to detect the health of composite. The subject will provide the new idea and method for the development of smart composite materials research and application.

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Jiang, Jian-Ping, and Dong-Xu Li. "Decentralized Robust Vibration Control of Smart Structures with Parameter Uncertainties." Journal of Intelligent Material Systems and Structures 22, no. 2 (2011): 137–47. http://dx.doi.org/10.1177/1045389x10391496.

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This study deals with decentralized robust vibration control of a smart composite panel with parameter uncertainties. The composite panel with four collocated piezoelectric actuators and velocity sensors is modeled using finite element method, and then the size of the model is reduced in the state space using Modal Hankel Singular Value. The parameter uncertainties presented by natural frequencies and modal damping ratios are considered in controller design process. To suppress the vibration induced by external disturbance, a decentralized robust H∞ controller is developed using linear matrix inequality techniques. Numerical simulation for the smart panel is performed in order to investigate the effectiveness of decentralized vibration control (DVC). When the system is subjected to an initial displacement field or distributed white noise disturbance, numerical results show that the DVC system is very effective. Although there are 20% parameter uncertainties for modal frequencies, damping ratio, and control input, the decentralized controller can effectively suppress the vibration excited by the external disturbance. Furthermore, the decentralized controller composed of four three-order systems can be practically implemented well.

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Tzou, H. S., and J. P. Zhong. "Electromechanics and Vibrations of Piezoelectric Shell Distributed Systems." Journal of Dynamic Systems, Measurement, and Control 115, no. 3 (1993): 506–17. http://dx.doi.org/10.1115/1.2899129.

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Smart piezoelectric structures, conventional passive materials integrated with piezoelectric sensors, actuators, and control electronics, have great potentials in many engineering applications. This paper is devoted to a new theoretical development of generic piezoelectric shell distributed systems. System electromechanical equations and boundary conditions for a thick piezoelectric shell continuum with symmetrical hexagonal structure (Class C6v = 6 mm) are derived using Hamilton’s principle and linear piezoelectric theory. Further simplification leads to a set of new electromechanical system equations, three translated coordinates and two rotary coordinates, for piezoelectric shell continua including rotary inertias and transverse shears. For thin piezoelectric shells, the second set system equations are further simplified using Kirchhoff-Love’s assumptions. The converse effect induced electric forces/moments and boundary conditions can be used to control system dynamics via open or closed-loop control systems. Applications of the theories to a plate and shells of revolution (spherical, cylindrical, and conical shells) are demonstrated in case studies.

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Wang, Dansheng, Junbing Zhang, and Hongping Zhu. "Embedded Electromechanical Impedance and Strain Sensors for Health Monitoring of a Concrete Bridge." Shock and Vibration 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/821395.

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Piezoelectric lead zirconate titanate (PZT) is one of the piezoelectric smart materials, which has direct and converse piezoelectric effects and can serve as an active electromechanical impedance (EMI) sensor. The design and fabrication processes of EMI sensors embedded into concrete structures are presented briefly. Subsequently, finite element modeling and modal analysis of a continuous rigid frame bridge are implemented by using ANSYS and MIDAS and validated by the field test results. Uppermost, a health monitoring technique by employing the embedded EMI and strain sensors is proposed in this paper. The technique is not based on any physical model and is sensitive to incipient structural changes for its high frequency characteristics. A practical study on health monitoring of the continuous rigid frame bridge is implemented based on the EMI and strain signatures. In this study, some EMI and strain sensors are embedded into the box-sectional girders. The electrical admittances of distributed EMI active sensors and the strains of concrete are measured when the bridge is under construction or in operation. Based on the electrical admittance and strain measurements, the health statuses of the continuous rigid frame bridge are monitored and evaluated successfully in the construction and operation stages using a root-mean-square deviation (RMSD) index.

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Balamurugan, V., and S. Narayanan. "Active vibration control of smart shells using distributed piezoelectric sensors and actuators." Smart Materials and Structures 10, no. 2 (2001): 173–80. http://dx.doi.org/10.1088/0964-1726/10/2/301.

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Zonta, Daniele, Matteo Pozzi, Marco Forti, and Paolo Zanon. "Vibration-Based Condition Monitoring of Smart Prefabricated Concrete Elements." Key Engineering Materials 293-294 (September 2005): 743–52. http://dx.doi.org/10.4028/www.scientific.net/kem.293-294.743.

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The University of Trento is promoting a research effort aimed at developing an innovative distributed construction system based on smart prefabricated concrete elements that can allow real-time assessment of the condition of bridge structures. So far, two reduced-scale prototypes have been produced, each consisting of a 0.2×0.3×5.6m RC beam specifically designed for permanent instrumentation with 8 long-gauge Fiber Optics Sensors (FOS) at the lower edge. The sensors employed are FBG-based and can measure finite displacements both in statics and dynamics. The acquisition module uses a single commercial interrogation unit and a softwarecontrolled optical switch, allowing acquisition of dynamic multi-channel signals from FBG-FOS, with a sample frequency of 625 Hz per channel. The performance of the system is undergoing validation in the laboratory. The scope of the experiment is to correlate changes in the dynamic response of the beams with different damage scenarios, using a direct modal strain approach. Each specimen is dynamically characterized in the undamaged state and in different condition states, simulating different cracking levels. The location and the extent of damage are evaluated through the calculation of damage indices which take into account changes in frequency and in strain-modeshapes. This paper presents in detail the results of the experiment as conducted on one of these prototypes and demonstrates how the damage distribution detected by the system is fully compatible with the damage extent appraised by inspection.

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Kwon, Il Bum, Chi Yeop Kim, and Dae Cheol Seo. "Application of Fiber Optic BOTDA Sensor for Fire Detection in a Building." Key Engineering Materials 321-323 (October 2006): 212–16. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.212.

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Smart structures are to be possessed many functions to sense the external effects, such as seismic loads, temperature, and impact by some explosion, influenced on the safety of structures. This work was focused on the development of a sensing function of smart structures to get the temperature distribution on structures to detect fire occurrences. A fiber optic BOTDA (Brillouin Optical Time Domain Analysis) sensor system was developed to detect the fire occurrence by measuring the temperature distribution of a building’s exterior surfaces. This fiber optic sensor system was constructed with a laser diode and two electro-optic modulators, which made this system faster than systems using only one electro-optic modulator. The temperature distributed on an optical fiber can be measured by this fiber optic BOTDA sensor. An optical fiber, 1400 m in length, was installed on the surface of a building. Using real-time processing of the sensor system, we were able to monitor temperature distribution on the building’s surfaces, and changes in temperature distribution were also measured accurately with this fiber optic sensor.

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Ng, T. Y., Hua Li, J. Q. Cheng, and K. Y. Lam. "A new hybrid meshless-differential order reduction (hM-DOR) method with applications to shape control of smart structures via distributed sensors/actuators." Engineering Structures 25, no. 2 (2003): 141–54. http://dx.doi.org/10.1016/s0141-0296(02)00116-5.

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Chen, Jian, Peng Li, Gangbing Song, Zhang Ren, Yu Tan, and Yongjun Zheng. "Feedback Control for Structural Health Monitoring in a Smart Aggregate Based Sensor Network." International Journal of Structural Stability and Dynamics 18, no. 05 (2018): 1850064. http://dx.doi.org/10.1142/s0219455418500645.

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The concept of smart aggregates, a distributed intelligent multi-purpose sensor network for civil structures, has been implemented to address three important issues including early-age concrete strength monitoring, impact detection and evaluation, and structural health monitoring. This paper presents mainly the employment of smart aggregates' active sensing property to form feedback in a sensor network to reduce damage-location detection time for lower power cost. Firstly, the concept of smart aggregates and the principle of a smart-aggregate-based sensor network are outlined. Next, the data pretreatment methods, including the sensor observation estimation model and the wavelet-packet-based signal processing algorithm, are proposed. A crucial concept using the damage index is also introduced. Moreover, the concept of the geometry structure matching method with the knowledge of an expert system is presented to determine which sensor is the optimal actuator. Finally, the data pretreatment algorithm and the geometry structure matching method are evaluated for a two-story concrete frame instrumented with smart aggregates as a testing object by means of actual experiments. The testing results demonstrate that the proposed algorithms are feasible and perform well in selecting optimal actuators of the sensor network for detecting damage locations.

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Zheng, Shijie, Xinwei Wang, and Wanji Chen. "The formulation of a refined hybrid enhanced assumed strain solid shell element and its application to model smart structures containing distributed piezoelectric sensors/actuators." Smart Materials and Structures 13, no. 4 (2004): N43—N50. http://dx.doi.org/10.1088/0964-1726/13/4/n02.

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Park, Jong Woong, Sung Han Sim, Hyung Jo Jung, and Billie F. Spencer. "Dynamic Displacement Estimation from Acceleration Measurements Using a Wireless Smart Sensor." Key Engineering Materials 558 (June 2013): 227–34. http://dx.doi.org/10.4028/www.scientific.net/kem.558.227.

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A displacement measurement provides useful information for structural health monitoring (SHM) as it is directly related to stiffness of the structure. Most existing methods of direct measurement such as the Laser Doppler Vibrometer (LDV) and the Liner Variable Differential Transformer (LVDT) are known to have accurate performance but have difficulties particularly in the use of large-scale civil structures as the methods rely on fixed reference points. Alternatively, indirect methods have been developed and widely used methods are Global Positioning System (GPS), vision-based displacement measurement system and displacement estimation from acceleration record. Among the indirect method, the use of accelerometer provides simple and economical in term of both hardware installation and operation. The major problem using acceleration based displacement estimation is low frequency drift caused by double integration. Recently, dynamic displacement estimation algorithm that addresses low-frequency drift problem has been developed. This study utilizes Wireless Smart Sensor (WSN) for estimating dynamic displacement from acceleration measurement in combination with the recently developed displacement estimation algorithm. Integrated into WSN that are low-cost, wireless, compatible with accelerometers, and capable of onboard computation, the displacement can be measured without limit of location on large-scale civil structures. Thus, this approach has the significant potential to impact many applications that require displacement measurements. With the displacement estimation algorithm embedded, the WSN performs in-network data processing to estimate displacements at each distributed sensor location wirelessly using only measured acceleration data. To experimentally validate the performance of displacement estimation using WSN for the use in structures with multiple-degree of freedom, the random vibration test is conducted on the three-story shear building model. The estimated displacement is compared with the reference displacements measured from the laser displacement sensor and the result shows good agreement.

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Wang, Dr Haoxiang. "IoT based Clinical Sensor Data Management and Transfer using Blockchain Technology." Journal of ISMAC 2, no. 3 (2020): 154–59. http://dx.doi.org/10.36548/jismac.2020.3.003.

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There has been revolutionary developments in the healthcare industry with the advancement of technology over the past years. Internet of Things, Cloud Computing, Blockchain technology, lab-on-chip, non-invasive and minimally invasive surgeries and so on has simplified several dreadful diseases. The research as well as healthcare industry have been greatly impacted by these new technologies. Clinical exams and self-health tracking can be done by means of miniaturized healthcare sensors that are powered by IoT. They help in early diagnosis and treatment guidance by clinicians at remote locations without directly being in contact with the users. The access control structures and inconsistent security policies have been a hinderance in meeting the security requirements of these data. Blockchain based smart contracts and enterprise-distributed ledger framework can be used for monitoring the vital signs of the patient. This enables accessing medical information of patients globally at any time along with immutable and extensive history log. In comparison with the traditional patient monitoring system, the proposed system offers better monitoring, improved connectivity and enhanced data security.

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Aboshosha, Bassam W., Mohamed M. Dessouky, and Ayman Elsayed. "Energy Efficient Encryption Algorithm for Low Resources Devices." Academic Research Community publication 3, no. 3 (2019): 26. http://dx.doi.org/10.21625/archive.v3i3.520.

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Saving energy is one of the most challenging aspects in the wireless network devices. Such devices are connected together to perform a certain task. A well-known example of these structures is the Wireless Sensor Network (WSN). Distributed WSN consists of several spread nodes in a harsh area. Therefore, once network has been established sensors replacement is not a possible option before at least five years which called network lifetime. So, it is a necessity to develop specific energy aware algorithms that could save battery lifetime as much as possible. Security and Privacy are the vital elements which need to be addressed to hold up to the trust of users in WSN environment. Because the majority of modern cryptographic algorithms were designed for desktop/server environments, many of these algorithms cannot be implemented in the constrained devices used by these networks. Symmetric key algorithms are a typically efficient and fast cryptosystem, so it has significant applications in many realms. For a WSN with constraint computational resources, the cryptosystem based on symmetric key algorithms is extremely suitable for such an agile and dynamic environment. Therefore, a Simple Lightweight Encryption Algorithm (SLEA) based on addition and subtraction operations and compact Substitution-boxes (S-boxes) is proposed for wireless networks due to its low energy consumption, simple hardware requirements and suitable level of security. In addition, the algorithm tries to overcome the limitations of both public- and symmetric-key protocols. It relies on a smart version of Feistel structure.

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Azizi, Aydin, and Ali Ashkzari. "Health Monitoring in Petrochemical Vessels." Advanced Materials Research 1030-1032 (September 2014): 983–86. http://dx.doi.org/10.4028/www.scientific.net/amr.1030-1032.983.

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Industrial structures deteriorate generally in an uncontrollable rate. To assess the short-term impact due to hazards and the long-term deterioration process due to physical aging and routine operation, structural health monitoring (SHM) is proposed. In this paper as a model of vessel a simply supported beam under constant distributed force is investigated. The objective is to estimate the severity of damage in a known location with sensing devices. As no actuation is consider the problem is solved statically. Finite element method by using MATLAB software to calculate the global stiffness matrix of the smart beam has been applied. It is expected the results show that higher severity of damage causes higher deflection and higher sensor of voltage.

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Rainieri, Carlo, Carmen Pannunzio, Yi Song, Giovanni Fabbrocino, Mark J. Schulz, and Vesselin Shanov. "The Status of Research on Self-Sensing Properties of CNT-Cement Based Composites and Prospective Applications to SHM." Key Engineering Materials 569-570 (July 2013): 759–66. http://dx.doi.org/10.4028/www.scientific.net/kem.569-570.759.

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Degradation phenomenacan affect civil structures over their lifespan. The recent advances innanotechnology and sensing allow to monitor the behaviour of a structure,assess its performance and identify damage at an early stage. Thus, maintenanceactions can be carried out in a timely manner, improving structural reliabilityand safety. Structural Health Monitoring (SHM) is traditionally performed at aglobal level, with a limited number of sensors distributed over a relativelylarge area of a structure. Thus, only major damage conditions are detectable. Densesensor networks and innovative structural neural systems, reproducing thestructure and the function of the human nervous system, may overcome thisdrawback of current SHM systems. Miniaturization and embedment are keyrequirements for successful implementation of structural neural systems. Carbonnanotubes (CNT) can play an attractive role in the development of embeddedsensors and smart structural materials, since they provide to traditionalmaterials like cement both structural capability and measurable response toapplied stresses, strains, cracks and other flaws. In this paper the mainresults of an extensive literature review about CNT/cement composites and theirself-sensing capabilities are summarized and critically revised. The analysisof experimental results and theoretical developments provides useful designcriteria for the fabrication of CNT/cement composites optimized for SHM applicationsin civil engineering.

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Arshid, Ehsan, Ali Kiani, and Saeed Amir. "Magneto-electro-elastic vibration of moderately thick FG annular plates subjected to multi physical loads in thermal environment using GDQ method by considering neutral surface." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, no. 10 (2019): 2140–59. http://dx.doi.org/10.1177/1464420719832626.

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The vibration analysis of an annular plate made up of functionally graded magneto-electro-elastic materials subjected to multi physical loads is presented. The plate is in thermal environment and temperature is distributed non-uniformly in its thickness direction. In addition, the plate is assumed moderately thick, the material properties vary through the thickness, and the exact neutral surface position is determined and took into account. According to Hamilton’s principle and the first-order shear deformation theory, the governing motion equations are extracted. Numerical results for various boundary conditions are obtained via the generalized differential quadrature method and are validated in simpler states with those of the literature. The effects of different parameters such as material property gradient index, multi physical loads, temperature variations, boundary conditions and geometric specifications of the plate on the natural frequencies and mode shapes are investigated. Temperature changes have little effect on the natural frequencies and the effect of electric potential on them is opposite of magnetic one. In other words, by increasing the magnetic potential, the rigidity of the plate increases too, and the frequency increases. The results of this study are useful to design more efficient sensors and actuators used in the smart or intelligent structures.

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El Mane, Adil, Marouane Chihab, Omar Bencharef, and Younes Chihab. "Architectural scheme of a multi-blockchain in the Agricultural field." E3S Web of Conferences 297 (2021): 01056. http://dx.doi.org/10.1051/e3sconf/202129701056.

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The blockchain represents structured and shared data. Instantly, it is a modern method of distributed databases controlled by a group of individuals. The goal is to store information, create a digital ledger of data, and dispatch them to each network-independent party. Blockchain technology gets used in many fields like government, transportation, healthcare, etc. This article will focus on the blockchain in the agricultural supply chain, especially the multi-blockchain scheme to enhance efficiency and track products. This kind of scheme requires the existence of two chains at least in one system. The article analyzes previous researches on how implementing this model and cites its various steps. Also, this research will offer a novel theoretical architecture inspired by the previous ones. The novel structure will avoid the errors that exist in previous experiments. This novel theoretical scheme uses sensors to provide us with environmental data. Subsequently, we use the multi-blockchain structure to stock our data in blocks. After that, we build Smart Contracts to control all the transactions and make decisions based on the conditions inside the source code of these automated contracts. This scheme would be more effective than the cloud and the simple blockchain storage.

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Jamil, Faisal, Shabir Ahmad, Naeem Iqbal, and Do-Hyeun Kim. "Towards a Remote Monitoring of Patient Vital Signs Based on IoT-Based Blockchain Integrity Management Platforms in Smart Hospitals." Sensors 20, no. 8 (2020): 2195. http://dx.doi.org/10.3390/s20082195.

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Over the past several years, many healthcare applications have been developed to enhance the healthcare industry. Recent advancements in information technology and blockchain technology have revolutionized electronic healthcare research and industry. The innovation of miniaturized healthcare sensors for monitoring patient vital signs has improved and secured the human healthcare system. The increase in portable health devices has enhanced the quality of health-monitoring status both at an activity/fitness level for self-health tracking and at a medical level, providing more data to clinicians with potential for earlier diagnosis and guidance of treatment. When sharing personal medical information, data security and comfort are essential requirements for interaction with and collection of electronic medical records. However, it is hard for current systems to meet these requirements because they have inconsistent security policies and access control structures. The new solutions should be directed towards improving data access, and should be managed by the government in terms of privacy and security requirements to ensure the reliability of data for medical purposes. Blockchain paves the way for a revolution in the traditional pharmaceutical industry and benefits from unique features such as privacy and transparency of data. In this paper, we propose a novel platform for monitoring patient vital signs using smart contracts based on blockchain. The proposed system is designed and developed using hyperledger fabric, which is an enterprise-distributed ledger framework for developing blockchain-based applications. This approach provides several benefits to the patients, such as an extensive, immutable history log, and global access to medical information from anywhere at any time. The Libelium e-Health toolkit is used to acquire physiological data. The performance of the designed and developed system is evaluated in terms of transaction per second, transaction latency, and resource utilization using a standard benchmark tool known as Hyperledger Caliper. It is found that the proposed system outperforms the traditional health care system for monitoring patient data.

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Breunig, Martin, Patrick Erik Bradley, Markus Jahn, et al. "Geospatial Data Management Research: Progress and Future Directions." ISPRS International Journal of Geo-Information 9, no. 2 (2020): 95. http://dx.doi.org/10.3390/ijgi9020095.

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Without geospatial data management, today’s challenges in big data applications such as earth observation, geographic information system/building information modeling (GIS/BIM) integration, and 3D/4D city planning cannot be solved. Furthermore, geospatial data management plays a connecting role between data acquisition, data modelling, data visualization, and data analysis. It enables the continuous availability of geospatial data and the replicability of geospatial data analysis. In the first part of this article, five milestones of geospatial data management research are presented that were achieved during the last decade. The first one reflects advancements in BIM/GIS integration at data, process, and application levels. The second milestone presents theoretical progress by introducing topology as a key concept of geospatial data management. In the third milestone, 3D/4D geospatial data management is described as a key concept for city modelling, including subsurface models. Progress in modelling and visualization of massive geospatial features on web platforms is the fourth milestone which includes discrete global grid systems as an alternative geospatial reference framework. The intensive use of geosensor data sources is the fifth milestone which opens the way to parallel data storage platforms supporting data analysis on geosensors. In the second part of this article, five future directions of geospatial data management research are presented that have the potential to become key research fields of geospatial data management in the next decade. Geo-data science will have the task to extract knowledge from unstructured and structured geospatial data and to bridge the gap between modern information technology concepts and the geo-related sciences. Topology is presented as a powerful and general concept to analyze GIS and BIM data structures and spatial relations that will be of great importance in emerging applications such as smart cities and digital twins. Data-streaming libraries and “in-situ” geo-computing on objects executed directly on the sensors will revolutionize geo-information science and bridge geo-computing with geospatial data management. Advanced geospatial data visualization on web platforms will enable the representation of dynamically changing geospatial features or moving objects’ trajectories. Finally, geospatial data management will support big geospatial data analysis, and graph databases are expected to experience a revival on top of parallel and distributed data stores supporting big geospatial data analysis.

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Liu, Shih-Chi. "Sensors, smart structures technology and steel structures." Smart Structures and Systems 4, no. 5 (2008): 517–30. http://dx.doi.org/10.12989/sss.2008.4.5.517.

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Tanaka, N., S. D. Snyder, and C. H. Hansen. "Distributed Parameter Modal Filtering Using Smart Sensors." Journal of Vibration and Acoustics 118, no. 4 (1996): 630–40. http://dx.doi.org/10.1115/1.2888345.

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This paper considers the design of distributed parameter modal sensors called “smart sensors,” with a particular emphasis on filtering the combination of appropriately weighted vibration modes providing a specific performance index in control strategy. First, with a two-dimensional distributed parameter sensor using a PVDF film, the necessary and sufficient condition for sensing the transformed modes of a structure is derived. Then, by considering the practicability of the two-dimensional sensors, an alternative approach based upon one-dimensional smart sensors is presented. It is found that the latter approach holds the necessary condition for sensing the transformed mode. This problem is overcome by introducing multiple one-dimensional smart sensors. Moreover, the design procedure for the multiple one-dimensional smart sensors for measuring the transformed mode is established. Finally, an experiment is conducted, demonstrating the validity of the smart sensors.

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Measures, R. M., M. LeBlanc, K. Liu, et al. "Fiber optic sensors for smart structures." Optics and Lasers in Engineering 16, no. 2-3 (1992): 127–52. http://dx.doi.org/10.1016/0143-8166(92)90005-r.

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Measures, Raymond M. "Smart composite structures with embedded sensors." Composites Engineering 2, no. 5-7 (1992): 597–618. http://dx.doi.org/10.1016/0961-9526(92)90045-8.

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Shaffer, P. L. "Distributed Control System for Turbine Engines." Journal of Engineering for Gas Turbines and Power 121, no. 1 (1999): 102–7. http://dx.doi.org/10.1115/1.2816295.

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A distributed control system (DCS) for a turbine engine has been demonstrated and tested, consisting of prototype electronic interface units (EIUs) connected to data and power busses. In the DCS, a central control computer communicated with smart sensors and smart actuators via a 2.5 megabit/sec digital data bus, using the Fields protocol. Power was distributed to the smart devices as 100 kHz 100V peak AC, allowing light, simple power converters at each smart device. All smart sensors, smart actuators, and cables were dual redundant. The smart actuators received position demand from the central control computer, exchanged data between channels to provide local redundancy management, closed the position loop locally, and reported actuator position to the central controller. Smart sensors converted sensed signals to digital values in engineering units, and performed local built-in tests. Testing of the DCS was done in a closed-loop simulation with an engine model. Frequency response of the DCS was almost identical with the conventional system.

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Turner, Roderick D., Tomas Valis, W. Dayle Hogg, and Raymond M. Measures. "Fiber-Optic Strain Sensors for Smart Structures." Journal of Intelligent Material Systems and Structures 1, no. 1 (1990): 26–49. http://dx.doi.org/10.1177/1045389x9000100103.

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Liu, Shih-Chi, Masayoshi Tomizuka, and Galip Ulsoy. "Strategic issues in sensors and smart structures." Structural Control and Health Monitoring 13, no. 6 (2006): 946–57. http://dx.doi.org/10.1002/stc.88.

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TZOU, H. S., H. J. LEE, and S. M. ARNOLD. "Smart Materials, Precision Sensors/Actuators, Smart Structures, and Structronic Systems." Mechanics of Advanced Materials and Structures 11, no. 4-5 (2004): 367–93. http://dx.doi.org/10.1080/15376490490451552.

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Jian, Kailin, and Michael I. Friswell. "Distributed Modal Sensors for Rectangular Plate Structures." Journal of Intelligent Material Systems and Structures 18, no. 9 (2007): 939–48. http://dx.doi.org/10.1177/1045389x06070589.

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Li, Hui, and Jin Ping Ou. "Smart Concrete, Sensors and Self-Sensing Concrete Structures." Key Engineering Materials 400-402 (October 2008): 69–80. http://dx.doi.org/10.4028/www.scientific.net/kem.400-402.69.

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Smart concrete technology provides a new alternative way for health monitoring of reinforced concrete structures. In this paper, the piezoresistivity of two kinds of smart concrete filled with carbon black or carbon fiber was studied, and two types of embedded sensors were fabricated using the smart concrete with favorable piezoresistivity. The sensing performance, the measuring methods and the response to environmental temperature and humidity of embedded sensors were investigated. A compensation circuit was incorporated to reduce the effect of temperature and humidity on the output of embedded sensors. The sensors were embedded in concrete beams and columns to monitor the structural compressive strain under field conditions. Experimental results indicate that the embedded sensors fabricated using smart concrete filled with carbon black or carbon fiber feature favorable sensing performance (gauge factors are 55.28 and 138 respectively). The self-sensing concrete components embedded with these sensors can realize the monitoring of their local compressive strain. It therefore can be concluded that the prepared smart concrete and the developed embedded sensors have great potential to be used for health monitoring and damage assessment of concrete structures.

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Singa, Naveen Kumar, Nilesh Jadhav, and Bony Mathew. "Distributed computing using SMART sensors in industrial automation framework." International Journal of Forensic Software Engineering 1, no. 1 (2019): 1. http://dx.doi.org/10.1504/ijfse.2019.10030652.

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Singa, Naveen Kumar, Nilesh Jadhav, and Bony Mathew. "Distributed computing using SMART sensors in industrial automation framework." International Journal of Forensic Software Engineering 1, no. 2/3 (2020): 215. http://dx.doi.org/10.1504/ijfse.2020.110621.

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Desforges, Xavier, Abdallah Habbadi, Laurent Geneste, and François Soler. "Distributed machining control and monitoring using smart sensors/actuators." Journal of Intelligent Manufacturing 15, no. 1 (2004): 39–53. http://dx.doi.org/10.1023/b:jims.0000010074.22952.de.

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Tanaka, Nobuo, Yoshihiro Kikushima, and Masaharu Kuroda. "Design Procedure of One-dimensional Distributed Parameter Smart Sensors." Transactions of the Japan Society of Mechanical Engineers Series C 61, no. 590 (1995): 3923–30. http://dx.doi.org/10.1299/kikaic.61.3923.

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Le Hir, Juliette, Anthony Kolar, and Filipe Vinci Dos Santos. "Distributed mixed-signal architecture for programmable smart image sensors." Analog Integrated Circuits and Signal Processing 97, no. 3 (2018): 493–501. http://dx.doi.org/10.1007/s10470-018-1342-y.

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Kim, Chi Yeop, Il Bum Kwon, and Dae Cheol Seo. "Wireless Instrumentation for Monitoring of Smart Structures." Key Engineering Materials 321-323 (October 2006): 192–95. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.192.

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Smart structures needs lots of sensor installation to sense their status and also the external environmental change. Wireless technique can give a good solution to install sensors without heavy cables. So, in this work, a wireless device was developed to transmit static strain and elastic wave propagation of structures. The specification of this device was as follows: 2.4 GHz of transmitted frequency, 8 channels, 57,600 bps of the transmitted speed, and 10 mW of the transmitted power. In order to confirm the wireless device’s feasibility, a beam test was performed with five optical fiber strain sensors and two piezo-ceramic sensors with the wireless instrumentation.

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Journal articles on the topic 'Smart structures; Distributed sensors'

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