A Low Cost Interrogation Method for Strain Monitoring in Bridge Beams

Author(s):  
Sravanthi Alamandala ◽  
V Durga Rama Pavan ◽  
R.L.N. Sai Prasad ◽  
P. Rathish Kumar
2019 ◽  
Vol 887 ◽  
pp. 633-640
Author(s):  
Enrique Gil ◽  
Fernando Gómez ◽  
Ángeles Mas ◽  
Jose Vercher ◽  
Carlos Lerma ◽  
...  

A reasonably accurate, low-cost system for the monitoring of strains in simple physical models within the field of Structural Engineering, based on Internet of Things, is presented, calibrated and discussed. The system only requires average, economic devices as Arduino microcontroller and strain gauges. Several tests on a case study of a scaled-cantilevered aluminium beam with different loading are conducted. Governing parameters are calibrated aimed at an optimization when benchmarked against theoretical and experimental results obtained with a reference device. Results show great accuracy; however, the need of setting of the parameters campaign-by-campaign, especially aimed at dealing with thermal drift, becomes a shortcoming. Still, its minimum cost and user-friendly management makes it a suitable solution for different applications.


2012 ◽  
Vol 226-228 ◽  
pp. 2062-2065
Author(s):  
Luan Xiong Chen ◽  
Wei Xu ◽  
Xu Guang Huang

In order to monitoring the health of the structure, a quasi-distributed fiber Bragg grating (FBG) interrogator based on two-channel theory of the arrayed waveguide grating (AWG) demultiplexer is presented. As is known, a slightly change of the temperature or strain or other related parameters applied on the FBG will lead to a shift of the Bragg wavelength of the FBG, which makes sense on the precisely temperature and strain monitoring of structures, including viaduct bridges, towers, railway, skyscraper, etc. It can be interrogated by the relative intensity of two-adjacent-channel of the AWG-based demultiplexer, which offers a low-cost, high sensitivity for the interrogation of FBG distributed sensors.


2014 ◽  
Vol 494-495 ◽  
pp. 979-982
Author(s):  
Shuang Rui Chen ◽  
Quan Sheng Yan ◽  
Shuang Cong Chen

In order to overcome the disconnection and high cost and maintenance difficulties of the conventional data collection systems for structure monitoring of long span bridge, we developed a low-cost and effective data acquisition system composed of several wireless communication modules connected to vibrating wire type sensors. This system has the function to change conventional wire-based data collector into wireless one instantly. The prototype of wireless data acquisition system for vibrating sensors is described in this paper. Laboratory tests demonstrate that the wireless data acquisition system is of high accuracy and good stability. In addition, the application of this system to the strain monitoring of a large steel box arch shows the wireless data acquisition system with good performance improve the efficiency of data acquisition and reduces the cost of monitoring.


2020 ◽  
Author(s):  
Umberto Giacomelli ◽  
Enrico Maccioni ◽  
Giorgio Carelli ◽  
Daniele Carbone ◽  
Salvatore Gambino ◽  
...  

<p>Rock strains detection is one of the principal ways to monitor geohazards. Classic strainmeters are cumbersome, hard to install and very expensive. Opto-electronics devices based on fiber Bragg grating technology allow to realize strainmeters with high sensitivity, low-cost, small volume and high performance.<br>We present the long term result of continuous soil strain monitoring on the Etna mount by a three-axial fiber Bragg grating sensor. The sensor has been developed in the framework of European Project MED-SUV (MEDiterranean SUpersite Volcanos). The installation site is a 8.5 meters deep borehole at a distance of about 7 km South-West from the summit craters of the Etna mount, at an elevation of about 1740 meters. This kind of sensor has a resolution better than 100 nanostrains on a daily timescale. Despite it is only a prototype, the sensor has worked for four years with a duty-cycle higher than 90% detecting both fast event, as earthquakes, and slow event, as epochal rocks strain behavior.</p>


Author(s):  
Y. L. Chen ◽  
S. Fujlshiro

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.


Author(s):  
J. D. Muzzy ◽  
R. D. Hester ◽  
J. L. Hubbard

Polyethylene is one of the most important plastics produced today because of its good physical properties, ease of fabrication and low cost. Studies to improve the properties of polyethylene are leading to an understanding of its crystalline morphology. Polyethylene crystallized by evaporation from dilute solutions consists of thin crystals called lamellae. The polyethylene molecules are parallel to the thickness of the lamellae and are folded since the thickness of the lamellae is much less than the molecular length. This lamellar texture persists in less perfect form in polyethylene crystallized from the melt.Morphological studies of melt crystallized polyethylene have been limited due to the difficulty of isolating the microstructure from the bulk specimen without destroying or deforming it.


Author(s):  
J. Temple Black

In ultramicrotomy, the two basic tool materials are glass and diamond. Glass because of its low cost and ease of manufacture of the knife itself is still widely used despite the superiority of diamond knives in many applications. Both kinds of knives produce plastic deformation in the microtomed section due to the nature of the cutting process and microscopic chips in the edge of the knife. Because glass has no well defined slip planes in its structure (it's an amorphous material), it is very strong and essentially never fails in compression. However, surface flaws produce stress concentrations which reduce the strength of glass to 10,000 to 20,000 psi from its theoretical or flaw free values of 1 to 2 million psi. While the microchips in the edge of the glass or diamond knife are generally too small to be observed in the SEM, the second common type of defect can be identified. This is the striations (also termed the check marks or feathers) which are always present over the entire edge of a glass knife regardless of whether or not they are visable under optical inspection. These steps in the cutting edge can be observed in the SEM by proper preparation of carefully broken knives and orientation of the knife, with respect to the scanning beam.


Author(s):  
H. O. Colijn

Many labs today wish to transfer data between their EDS systems and their existing PCs and minicomputers. Our lab has implemented SpectraPlot, a low- cost PC-based system to allow offline examination and plotting of spectra. We adopted this system in order to make more efficient use of our microscopes and EDS consoles, to provide hardcopy output for an older EDS system, and to allow students to access their data after leaving the university.As shown in Fig. 1, we have three EDS systems (one of which is located in another building) which can store data on 8 inch RT-11 floppy disks. We transfer data from these systems to a DEC MINC computer using “SneakerNet”, which consists of putting on a pair of sneakers and running down the hall. We then use the Hermit file transfer program to download the data files with error checking from the MINC to the PC.


Author(s):  
T. P. Nolan

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.


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