scholarly journals A Running Reference Analysis Method to Greatly Improve Optical Backscatter Reflectometry Strain Data from the Inside of Hardening and Shrinking Materials

2018 ◽  
Vol 8 (7) ◽  
pp. 1137 ◽  
Author(s):  
Søren Heinze ◽  
Andreas Echtermeyer

Due to the increasing ease of use and the superiority of the results, distributed strain measurements, utilizing Optical Backscatter Reflectometry (OBR), have become more important and widespread over the last few years. Strains are calculated from the difference between an actual optical Raleigh backscattering measurement and an initial reference value. However, under certain physical conditions, e.g., pinching or microbending of the optical fiber, no meaningful strain values are yielded by the commonly-used method to analyze OBR data. Such conditions were experienced in this study where the optical fiber was embedded into hardening epoxy for measuring shrinkage due to curing. In this work, it is shown that a new data analysis method called the “running reference analysis method” can overcome such obstacles and deliver meaningful strain values in circumstances in which the traditional method fails. In the new approach, each measurement is compared to the previous measurement, and the strain differences are added up to the absolute strain value. This method does not require a new experimental technique and will also work on old measurement files. It is also useful for other types of (OBR) strain measurements that contain many outliers and is not restricted to the investigation of cured epoxy.

2007 ◽  
Vol 2007.6 (0) ◽  
pp. 209-210
Author(s):  
Kohei OHARA ◽  
Hideaki MURAYAMA ◽  
Kazuro KAGEYAMA ◽  
Isao OSAWA ◽  
Kiyoshi UZAWA ◽  
...  

2010 ◽  
Vol 18 (25) ◽  
pp. 26484 ◽  
Author(s):  
Dragan Coric ◽  
Marco Lai ◽  
John Botsis ◽  
Aiping Luo ◽  
Hans G. Limberger

Author(s):  
Martin Weisbrich ◽  
Klaus Holschemacher

Optical fiber measurement systems have recently gained popularity following a multitude of intensive investigations. A new technique has been developed for these measurement systems that uses Rayleigh backscatter to determine the distributed strain measurement over the total length of a fiber. These measurement systems have great potential in civil engineering and structural health monitoring. This paper addresses some preliminary comparisons between three different fiber coatings and six different adhesives on steel structures. The results are based on a bending test with specimens made of precision flat steel; optical fiber strain measurements were compared with photogrammetric strain measurements. Analysis of the test data showed a strong correlation between the optical measurement system’s results and the theoretical results up to the yielding point of the steel. Furthermore, the results indicate that fibers with the Ormocer® and polyimide coatings have almost no loss in the strain measurements. The main results of this investigation are a guideline describing how to attach optical fibers to steel surfaces for distributed fiber optical strain measurements and recommendations for coatings to obtain realistic strain values. Additionally, the advantages of distributed strain measurements were revealed, which illustrates the potential of Rayleigh backscattering applications.


Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 141
Author(s):  
Ismail Alj ◽  
Marc Quiertant ◽  
Aghiad Khadour ◽  
Quentin Grando ◽  
Karim Benzarti

The present study investigates the environmental durability of a distributed optical fiber sensing (DOFS) cable on the market, commonly used for distributed strain measurements in reinforced concrete structures. An extensive experimental program was conducted on different types of specimens (including samples of bare DOFS cable and plain concrete specimens instrumented with this DOFS cable) that were exposed to accelerated and natural ageing (NA) conditions for different periods of up to 18 months. The instrumentation of both concrete specimens consisted of DOFS cables embedded at the center of the specimens and bonded at the concrete surface, as these two configurations are commonly deployed in the field. In these configurations, the alkalinity of the surrounding cement medium and the outdoor conditions are the main factors potentially affecting the characteristics of the DOFS component materials and the integrity of the various interfaces, and hence impacting the strain transfer process between the host structure and the core optical fiber (OF). Therefore, immersion in an alkaline solution at an elevated temperature or freeze/thaw (F/T) and immersion/drying (I/D) cycles were chosen as accelerated ageing conditions, depending on the considered configuration. Mechanical characterizations by tensile and pull-out tests were then carried out on the exposed specimens to assess the evolution of the mechanical properties of individual component materials as well as the evolution of bond properties at various interfaces (internal interfaces of the DOFS cable, and interface between the cable and the host structure) during ageing. Complementary physico-chemical characterizations were also performed to better understand the underlying degradation processes. The experimental results highlight that immersion in the alkaline solution induced a significant and rapid decrease in the bond properties at internal interfaces of the DOFS cable and at the cable/concrete interface (in the case of the embedded cable configuration), which was assigned to chemical degradation at the surface of the cable coating in contact with the solution (hydrolysis and thermal degradation of the EVA copolymer component). Meanwhile, F/T and I/D cycles showed more limited effects on the mechanical properties of the component materials and interfaces in the case of the bonded cable configuration. A comparison with the same specimens exposed to outdoor NA suggested that the chosen accelerated ageing conditions may not be totally representative of actual service conditions, but provided indications for improving the ageing protocols in future research. In the last part, an analysis of the distributed strain profiles collected during pull-out tests on instrumented concrete specimens clearly illustrated the consequences of ageing processes on the strain response of the DOFS cable.


2018 ◽  
Vol 7 (2) ◽  
pp. 601-608 ◽  
Author(s):  
Martin Weisbrich ◽  
Klaus Holschemacher

Abstract. Optical fiber measurement systems have recently gained popularity following a multitude of intensive investigations. A new technique has been developed for these measurement systems that uses Rayleigh backscatter to determine the distributed strain measurement over the total length of a fiber. These measurement systems have great potential in civil engineering and structural health monitoring. This paper addresses some preliminary comparisons between three different fiber coatings and six different adhesives on steel structures. The results are based on a bending test with specimens made of precision flat steel; optical fiber strain measurements were compared with photogrammetric strain measurements. Analysis of the test data showed a strong correlation between the optical measurement system's results and the theoretical results up to the yielding point of the steel. Furthermore, the results indicate that fibers with the Ormocer® and polyimide coatings have almost the same strain values as the reference measurement method. The main results of this investigation are a guideline describing how to attach optical fibers to steel surfaces for distributed fiber optical strain measurements and recommendations for coatings to obtain realistic strain values. Additionally, the advantages of distributed strain measurements were revealed, which illustrates the potential of Rayleigh backscattering applications.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Leijun Hu ◽  
Liwen Sheng ◽  
Jisong Yan ◽  
Ligong Li ◽  
Ming Yuan ◽  
...  

A multiparameter Brillouin fiber-optic sensor for distributed strain and temperature information measuring based on spontaneous scattering in a common communication optical fiber (the G. 652. D commercial fiber) is presented and experimentally demonstrated. Benefiting from the difference of the temperature and strain sensitivity from different Brillouin peaks with different acoustic modes, our proposed sensing configuration can be used to distinguish ambient temperature and applied strain at the same time, which is an excellent candidate to address the problem of cross-sensitivity in the classical Brillouin system. In the experimental section, using a 21.8 km sensing length of communication optical fiber, a temperature accuracy of 1.13°C and a strain accuracy of 21.46 με are obtained simultaneously. Considering the performance we achieved now, the proposed innovation and experimental setup will have some potential applications in the field of fiber sensors.


2020 ◽  
Vol 6 (2) ◽  
pp. 187-197
Author(s):  
Nurlaila Suci Rahayu Rais ◽  
Dedeh Apriyani ◽  
Gito Gardjito

Monitoring of warehouse inventory data processing is an important thing for companies. PT Talaga mulya indah is still manual using paper media, causing problems that have an effect on existing information, namely: problems with data processing of incoming and outgoing goods. And the difference between data on the amount of stock of goods available with physical data, often occurs inputting data more than once for the same item, searching for available data, and making reports so that it impedes companies in monitoring inventory of existing stock of goods. Which aims to create a system that can provide updated information to facilitate the warehouse admin in making inventory reports, and reduce errors in input by means of integrated control. In this study, the authors used the data collection method used in this analysis using the method of observation, interviews, and literature review (literature study). For analysis using the PIECES analysis method. Furthermore, the system design used is UML (Unified Modeling Language). The results of this study are expected to produce the right data in the process of monitoring inventory data processing, also can provide the right information and make it easier to control the overall availability of goods.


Manuskripta ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Novarina Novarina

Abstract: This research is a comparative literary study that uses Malay and Javanese versions of Mahabarata text sources. The research objects used were the text edition of Pandhawa Gubah (PG) by Sudibjo Z. Hadisutjipto and the text of Cheritera Pandawa Lima (CPL) by Khalid Hussain. The research method used is descriptive-analysis method. In the comparative study used a comparative literary theory proposed by Endraswara (2011). The results of the text comparison reveal the similarities and differences in the image of Bima figures in the Javanese and Malay versions. The equation as a whole is that both texts contain the same heroic storyline and heroic character, Bima. In addition, Indian influence is still evident in the two texts seen from the nuances of Hinduism that exist in both texts. While the difference is seen in the events that accompany Bima's struggle in achieving his victory. Based on these similarities and differences, it can be seen that the authors attempt to represent the concept of metaphysical interactions vertically and horizontally expressed through PG text. --- Abstrak: Penelitian ini adalah satu kajian sastra bandingan yang menggunakan sumber teks Mahabarata versi Melayu dan Jawa. Objek penelitian yang digunakan adalah edisi teks Pandhawa Gubah (PG) karya Sudibjo Z. Hadisutjipto dan teks Cheritera Pandawa Lima (CPL) karya Khalid Hussain. Metode penelitian yang digunakan adalah metode deskriptif-analisis. Dalam telaah perbandingan digunakan teori sastra bandingan yang dikemukakan Endraswara (2011). Hasil perbandingan teks mengungkapkan adanya persamaan dan perbedaan citra tokoh Bima dalam versi Jawa maupun versi Melayu. Persamaan secara keseluruhan adalah kedua teks tersebut mengandung alur cerita kepahlawanan dan tokoh pahlawan yang sama yaitu Bima. Selain itu, pengaruh India masih tampak dalam kedua teks tersebut dilihat dari nuansa Hinduisme yang ada dalam kedua teks. Sementara perbedaannya tampak pada peristiwa-peristiwa yang menyertai perjuangan Bima dalam mencapai kemenangannya. Berdasarkan persamaan dan perbedaan tersebut tampak adanya upaya penulis untuk merepresentasikan konsep interaksi metafisik secara vertikal dan horizontal yang diungkapkan melalui teks PG.


Metahumaniora ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 368
Author(s):  
Gilang Januarsyah

ABSTRAKUntuk menghasilkan sebuah karangan berbahasa Perancis yang dapat dipahamioleh khalayak umum, mahasiswa harus menguasai kemampuan berbahasa Perancis ragamtulis yang baik dan benar sesuai dengan kaidah yang berlaku. Penelitian ini bertujuanuntuk menjelaskan kesalahan sintaksis yang dilakukan oleh mahasiswa Program StudiSastra Perancis Universitas Padjadjaran. Data yang digunakan dalam penelitian ini diambildari sepuluh karangan mahasiwa yang duduk di semester lima dan tujuh dan dianalisisdengan menggunakan metode simak dan metode analisis padan referensial translasionaldengan pendekatan kualitatif. Hasil dari penelitian ini menunjukkan bahwa kesalahantertinggi yang dilakukan mahasiswa adalah kesalahan dalam penggunaan passé composédan imparfait sebesar 50%, kemudian diikuti oleh kesalahan dalam penggunaan pronomrelatif simple et composé ‘pronomina penghubung bebas dan turunan’ sebesar 30%, danterakhir kesalahan dalam penggunaan pronom COD et COI ‘pronomina COD dan COI’ sebesar20%. Faktor yang menyebabkan terjadinya kesalahan tersebut adalah faktor linguistikyang disebabkan oleh perbedaan kaidah tatabahasa bahasa Indonesia dan Perancis.Selain itu terdapat pula faktor sosiolinguistik yang disebabkan oleh jarangnya mahasiswamembiasakan diri mereka untuk mengaplikasikan bahasa Perancis di luar kelas.Kata kunci: kesalahan, sintaksis, bahasa Perancis, tulis, pengajaranABST RACTTo produce a French-language essay that can be understood by the general public,the students should master the ability of French language in good and true writing skill inaccordance with the applicable rules. The aim of this research is to explain the syntactic errorsmade by students of French literature’s program at University Padjadjaran. The sources ofdata are taken from the ten student essays who sit in the fifth and seventh semesters, and themethods used in this research are Observation Method ‘Metode Simak’ and the analyticalreference translational analysis method with a qualitative approach. The results of thisresearch indicate that the highest errors that students make are the use of passé composéand imparfait as much as fifty percent, followed by errors in the use of pronom relatifsimple et composé ‘the free and derivative pronouns’ thirty percent, and the last error is inthe use of pronom CO D et CO I ‘‘The COD and COI pronouns’ twenty percent. The factors thatcause those errors are a linguistic caused by the difference rules of Indonesian and Frenchgrammar. In addition there are also sociolinguistic factors caused by the rarity of studentsfamiliarize themselves to apply the French language outside the classroom.Keywords: Error, syntax, French language, writing, teaching


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