Academic literature on the topic 'Bending strain measurement'
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Journal articles on the topic "Bending strain measurement"
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Li, Rui, Zhensheng Wang, and Pengchao Chen. "Development the method of pipeline bending strain measurement based on microelectromechanical systems inertial measurement unit." Science Progress 103, no. 2 (April 2020): 003685042092523. http://dx.doi.org/10.1177/0036850420925231.
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With the development of pipeline construction, the additional stress and strain becomes the key factor to induce the damage for oil and gas pipeline. The in-line inspection of pipeline bending strain which is based on high-end tactical-grade inertial measurement unit has become routine practice for the oil and gas pipelines over recent years. However, these accurate inertial measurement units are large size and high cost limit to use in small diameter pipelines of bending strain inspection. Microelectromechanical systems–based inertial navigation has been applied to mapping the centerline of the small size pipeline, and the accurate trajectory and attitude information become key factors to calculate the bending strain of pipelines. This article proposed a method not only to calculate the pipeline bending strain but also to improve the accuracy for the bending strain based on the wavelet analysis. Tests show that this method can be effectively used in the calculation and optimization of the bending strain, and it will increase the accuracy to within 19.1% of the actual bending strain.
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Ridge, I. M. L., J. Zheng, and C. R. Chaplin. "Measurement of cyclic bending strains in steel wire rope." Journal of Strain Analysis for Engineering Design 35, no. 6 (August 1, 2000): 545–58. http://dx.doi.org/10.1243/0309324001514288.
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This paper reports strain gauge measurements of cyclic bending strain in the wires of a six-strand right-handed Lang's lay steel wire rope running on and off a pulley. The paper describes the measurement procedures and presents the results for the two tests conducted which had different gauge configurations along and around the sample. It was found that the strain waveforms observed had some similarities with those reported elsewhere and the magnitudes of strains matched theoretical predictions. However, in contrast with behaviour reported for fluctuating tension, the initial differences between and along wires rapidly attenuated. This observation helps to explain reported similarities in bending fatigue performance of ropes from different sources which contrasts with the very significant differences in characteristics found in tensile fatigue. The dependence of wire strain amplitude on rope bending deformation further contrasts with tensile fatigue in which wire strain range is dependent on the local sharing of axial load.
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Liu, Shucong, Dezhi Zheng, Tianhao Wang, Mengxi Dai, Rui Li, and Qingshan Feng. "A novel algorithm for pipeline displacement and bending strain of in-line inspection based on inertia measurement technology." Advances in Mechanical Engineering 10, no. 12 (December 2018): 168781401881675. http://dx.doi.org/10.1177/1687814018816755.
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The in-line inspection tool with Inertial Measurement Unit tool is becoming a routine and important practice for many pipeline companies and is effective for whole-line bending strain measurement. However, the measurements of Inertial Measurement Unit tool are always affected by noises and errors, which are caused by inherent inaccuracies and deficiencies of the experimental techniques and measuring devices. For the calculations of the bending strain, the results are very sensitive to the noises and errors. A filtering algorithm based on cubic spline interpolation was proposed for Inertial Measurement Unit data processing to eliminate noises and errors for bending strain, and the effectiveness is validated through the pipeline field test. The results showed that the average pipeline displacement deviation declined 13.82% in the three tests, and the bending strain error reduced from 0.037% to 0.014%. The proposed method effectively improves the inspection accuracy and provides an effective method for pipeline displacement and strain inspection, which ensures the safe operation of the pipeline.
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Panich, Sansot. "Bending Limit Curves in Sheet Metal Bending Evaluation." Key Engineering Materials 751 (August 2017): 180–85. http://dx.doi.org/10.4028/www.scientific.net/kem.751.180.
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Bending and hemming process are used in automotive industries for assembling the car body panel.The main failure mechanism under bending loads is the intercrystalline fracture. This is due to the fact that the Forming Limit Curve (FLC) describes first occurrence of membrane instability and no material failure in consequence of an intercrystalline fracture at bending.The FLC fails to predict the formability in hemming processes since difference in failure mechanism. A new failure criterion, the so-called Bending Limit Curve (BLC) has been developed. In this work, the left hand side BLCs are experimentally determined for Advanced High Strength Steel grade DP1000, Stainless Steel grade SUS430 and Deep Drawing Steel grade SPCC having a thickness of 1.0 mm. The influence of various bending radii and level of pre-strain on the bending strains are investigated and discussed by using the Three Point Bending Test. Bendability of investigated materials are evaluated by using optical strain measurement system GOM-Aramis to determine maximal achievable bending strain on the specimens. The developed left hand side BLCs were found to be higher level than conventional FLCs. The bigger bending radius established lower bending limit strain. The higher bending strain was obtained from the higher pre strain level.
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Socha, Bernard J., Edward T. Bednarz, and Wei-Dong Zhu. "A combined loading transducer for calculating the bending moment and torque in a slender circular beam using the minimum numbers of strain gauges, strain grids, and measurement channels." International Journal of Distributed Sensor Networks 16, no. 6 (June 2020): 155014772092177. http://dx.doi.org/10.1177/1550147720921774.
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The purpose of this work is to develop a new methodology that uses the minimum numbers of strain gauges, strain grids, and measurement channels to calculate the bending moment and torque in a slender circular beam under combined loading from measured strains in it. In general, each independent variable requires a minimum of one independent measurement. Two grids of a single-rosette strain gauge located at 45° and −45° from the longitudinal axis of the beam are used in conjunction with two measurement channels to gather all measurements and form a combined loading transducer. A theoretical set of equations of the new methodology is developed to minimize numbers of strain grids and measurement channels, and an experimental configuration was tested in a variety of scenarios. Calibration factors were independently developed for the bending moment and torque of the beam by separately loading it in their respective directions. These calibration factors were applied to different combined loading scenarios, where errors were found to be on average 1.6% for moment comparison and 6.7% for torque comparison.
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Li, Rui, Maolin Cai, Yan Shi, Qingshan Feng, Shucong Liu, and Xiaoming Zhao. "Pipeline Bending Strain Measurement and Compensation Technology Based on Wavelet Neural Network." Journal of Sensors 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/8363242.
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The bending strain of long distance oil and gas pipelines may lead to instability of the pipeline and failure of materials, which seriously deteriorates the transportation security of oil and gas. To locate the position of the bending strain for maintenance, an Inertial Measurement Unit (IMU) is usually adopted in a Pipeline Inspection Gauge (PIG). The attitude data of the IMU is usually acquired to calculate the bending strain in the pipe. However, because of the vibrations in the pipeline and other system noises, the resulting bending strain calculations may be incorrect. To improve the measurement precision, a method, based on wavelet neural network, was proposed. To test the proposed method experimentally, a PIG with the proposed method is used to detect a straight pipeline. It can be obtained that the proposed method has a better repeatability and convergence than the original method. Furthermore, the new method is more accurate than the original method and the accuracy of bending strain is raised by about 23% compared to original method. This paper provides a novel method for precisely inspecting bending strain of long distance oil and gas pipelines and lays a foundation for improving the precision of inspection of bending strain of long distance oil and gas pipelines.
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Yu, Feng, and Michael T. Hendry. "A new strain gauge configuration on the rail web to decouple the wheel–rail lateral contact force from wayside measurement." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 233, no. 9 (January 13, 2019): 951–60. http://dx.doi.org/10.1177/0954409718822870.
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The simultaneous presence of bending moments and torques produced by the lateral and vertical contact forces between the wheel and the rail generates a complex strain state on the rail surface, which makes it difficult to identify the strain signals produced purely from the lateral contact force. In this study, a new strain gauge configuration is proposed to decouple strain signals of the wheel–rail lateral contact force from wayside measurements by analyzing the bending strains on the rail web using a full Wheatstone bridge. For this purpose, a finite element modeling of the wheel–rail contact is performed to analyze the bending strains on the rail web and to optimize two instrumented sections for eight electric resistance strain gauges. Laboratory testing is also used to examine the installation scheme of the strain gauges at the two optimal instrumented sections. A good agreement is observed between the experimental data and the simulation results. Strain signals are evenly distributed for about 10 cm in the middle region between the two optimal instrumented sections and only account for the lateral contact force.
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Leski, Andrzej, Wojciech Wronicz, Piotr Kowalczyk, Michał Szmidt, Robert Klewicki, Karol Włodarczyk, and Grzegorz Uliński. "Modular Test Stand for Fatigue Testing of Aeronautical Structures – Verification of Assumptions." Fatigue of Aircraft Structures 2020, no. 12 (December 1, 2020): 78–91. http://dx.doi.org/10.2478/fas-2020-0008.
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Abstract The Modular Test Stand was developed and manufactured to decrease the cost of fatigue testing and reduce the time of its completion as well as to enable testing specimens under more complex load conditions. The stand consists of three connected sections, similar to a wing box, all being loaded in the same way. Thanks to that, several specimens can be tested simultaneously. This configuration requires that stress and strain distribution should be reasonably uniform, as assumed in the design stage. The structure can be loaded with bending or torsion. A whole section, selected structural node or a specimen mounted in the structure as well as a repair or a sensor can be a test object. Two stands, one for bending and one for torsion were prepared. This paper presents the verification of the assumed strain and stress distributions on the skin panels. The measurements were performed with the use of Digital Image Correlation (DIC) as well as strain gauges. DIC measurements were performed on one skin panel of the central section. Five strain gauge rosettes were installed on both panels of the one section. In addition, one rosette was applied to one skin panel in each of two other sections. Measurements were performed on the stand for torsion as well as on the stand for bending. The results of DIC analysis and strain gauge measurement during torsion show uniform shearing strain distributions on the panels. During bending, on the tensioned side, the strains obtained indicate quite uniform strain distributions. On the compressed side, local buckling of the skin panels results in high strain gradients. Strain levels obtained with the use of a DIC analysis and strain gauge measurements were similar. Moreover, horizontal displacements of markers in the spar axis during bending was determined based on a series of photographic. The deflection line obtained in this way has a shape similar to arc, which is characteristic of the constant bending moment. The stand was tested with torsional and bending loads in order to verify the design assumptions. The results of strain distributions on the skin panels with the use of DIC and strain gauges as well as the deflection line of the spar axis indicate that the Modular Test Stand performs as assumed and can be used for tests.
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Devivier, C., Daniel Thompson, Fabrice Pierron, and M. R. Wisnom. "Correlation between Full-Field Measurements and Numerical Simulation Results for Multiple Delamination Composite Specimens in Bending." Applied Mechanics and Materials 24-25 (June 2010): 109–14. http://dx.doi.org/10.4028/www.scientific.net/amm.24-25.109.
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This paper studies the effect of delaminations on strain maps for a simple cantilever beam. The aim is to build an experimental set-up which allows detecting very slight modifications in the strain maps. The case studied is a single delamination on the mid-plane. The measurement method is the deflectometry technique which enables direct slope measurements on a reflective specimen. The comparison with finite element models clearly indicated that the surface strains bear the information of the extent of the delamination. The second step is to use these surface strains to identify a stiffness reduction map for real impact damages.
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Xu, Y., and R. N. Miles. "FULL-FIELD RANDOM BENDING STRAIN MEASUREMENT OF A PLATE FROM VIBRATION MEASUREMENT." Journal of Sound and Vibration 191, no. 5 (April 1996): 847–58. http://dx.doi.org/10.1006/jsvi.1996.0159.
Full textDissertations / Theses on the topic "Bending strain measurement"
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TANAKA, Keisuke, Yoshiaki AKINIWA, Yoshihisa SAKAIDA, and Hirohisa KIMACHI. "Lattice Strain and Domain Switching Induced in Tetragonal PZT by Poling and Mechanical Loading." The Japan Society of Mechanical Engineers, 2000. http://hdl.handle.net/2237/9183.
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Oscarsson, Jan. "Strength grading of structural timber and EWP laminations of Norway spruce : Development potentials." Licentiate thesis, SP Sveriges Tekniska Forskningsinstitut, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-23757.
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Strength grading of structural timber is a process by which value is added to sawn products. It is to the greater part carried out using machine grading based on statistical relationships between so called indicating properties and bending strength. The most frequently applied indicating property (IP) on the European market is the stiffness in terms of average modulus of elasticity (MOE) of a timber piece, although MOE is a material property that varies within timber. A major limitation of today’s grading methods is that the described relationships are relatively poor, which means that there is a potential for more accurate techniques. The main purpose of this research has been to initiate development of more accurate and efficient machine grading methods. Strength of timber is dependent on the occurrence of knots. At the same time, knot measures applied as indicating properties until today have shown to be poor predictors of strength. However, results from this research, and from previous research, has shown that not only size and position of knots but also fibre deviations in surrounding clear wood are of great importance for local stiffness and development of fracture under loading. Thus, development of new indicating properties which take account of knots as well as properties of surrounding fibres, determined on a very local scale, was considered as a possible path towards better strength grading. In the research, results from contact-free deformation measurements were utilized for analysis of structural behaviour of timber on both local and global level. Laser scanning was used for detection of local fibre directions projected on surfaces of pieces. Scanned information, combined with measures of density and average axial dynamic MOE, was applied for calculation of the variation of local MOE in the longitudinal board direction. By integration over cross-sections along a piece, a stiffness profile in edgewise bending was determined and a new IP was defined as the lowest bending MOE along the piece. For a sample of Norway spruce planks, a coefficient of determination of 0.68 was achieved between the new IP and bending strength. For narrow side boards to be used as laminations in wet-glued glulam beams, the relationship between IP and tensile strength was as high as 0.77. Since the intended use of the narrow boards was as laminations in wet-glued beams, the possibility of grading them in a wet state was also investigated. Grading based on axial dynamic excitation and weighing gave just as good results in a wet state as when the same grading procedure was applied after drying. It was also found that the relationship between the new IP and strength was dependent on what scale the IP was determined. Optimum was reached for moving average MOE calculated over lengths corresponding with approximately half the width of investigated pieces. Implementation of the new IP will result in grading that is more accurate than what is achieved by the great majority of today’s grading machines. The new method will probably also be particularly favourable for development of engineered wood products made of narrow laminations.Hållfasthetssortering av konstruktionsvirke innebär att värdet på sågade produkter ökar. Sorteringen genomförs oftast med maskinella metoder baserade på statistiska samband mellan s.k. indikerande egenskaper och böjhållfasthet. Den indikerande egenskap (indicating property, IP) som är vanligast på den Europeiska marknaden är styvhet uttryckt som ett medelvärde för elasticitetsmodulen (modulus of elasticity, MOE) i ett virkesstycke, trots att MOE är en materialegenskap som varierar i virket. En betydande begränsning med dagens sorteringsmetoder är att de beskrivna sambanden är förhållandevis svaga, vilket innebär att det finns en potential för metoder med högre noggrannhet. Det huvudsakliga syftet med detta doktorandprojekt har varit att initiera en utveckling mot sådana metoder. Hållfasthet hos virke är beroende av förekomst av kvistar. Samtidigt har de kvistmått som fram till idag kommit till användning visat sig vara dåliga prediktorer av hållfasthet. Resultat från såväl denna som tidigare forskning har dock visat att inte bara kvistars storlek och läge, utan också variationen i fiberriktning i omgivande träfibrer, är av stor betydelse för lokal styvhet och brottförlopp under inverkan av last. Utveckling av nya IP som tar hänsyn till såväl kvistar som omgivande träfibrers egenskaper fastställda på mycket lokal nivå bedömdes vara en möjlig väg för att uppnå bättre hållfasthetssortering. I detta doktorandprojekt användes beröringsfri deformationsmätning för analys av det strukturella beteendet hos virkesstycken på såväl lokal som global nivå. Laserskanning utnyttjades för detektering av lokala fiberriktningar projicerade på virkesstyckenas ytor. Med utgångspunkt från skannad information, virkesdensitet och medelvärde för axiell dynamisk elasticitetsmodul kunde variationen i lokal elasticitetsmodul i virkesstyckenas längdriktning bestämmas. Genom integration över tvärsektioner längs ett virkesstycke kunde en profil över hur böjstyvheten i styva riktningen varierade i virkesstyckets längdriktning beräknas. En ny IP definierades som den lägsta elasticitetsmodulen i böjning utmed virkesstyckets längd. För ett urval av granplankor erhölls en förklaringsgrad på 0.68 mellan den nya indikerande egenskapen och böjhållfasthet. För smala sidobrädor avsedda att användas som lameller i våtlimmade limträbalkar var motsvarande förklaringsgrad mellan samma IP och draghållfasthet så hög som 0.77. Eftersom sidobrädorna var avsedda att användas som lameller i våtlimmade balkar genomfördes en studie avseende möjligheten att hållfasthetssortera i vått tillstånd med hjälp av axiell dynamisk excitering och vägning. Det visade sig att sådan sortering gav lika bra resultat som då samma metod användes efter torkning. Sambandet mellan den nya indikerande egenskapen och hållfasthet visade sig också vara beroende av på vilken lokal nivå som egenskapen beräknades. Optimum uppnåddes då den bestämdes som ett glidande medelvärde beräknat över en längd motsvarande ungefär halva virkesstyckets höjd. Implementering av den nya sorteringsmetoden kommer att resultera i sortering som är noggrannare än vad som kan erhållas med det stora flertalet av de sorteringsmetoder som finns idag. Den nya indikerande egenskapen kommer sannolikt att bli särskilt gynnsam att använda för utveckling av ingenjörsmässiga träprodukter bestående av smala lameller.
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Feng, Chih-Min, and 馮智敏. "Digital Image Analysis for Strain Measurement of Flexible Substrate under Bending Test." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/35522950857470760578.
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碩士國立交通大學
機械工程系所
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Flexible electronic is important development in modern technology. One of the most widespread applications is “flexible display”, which is mainly developed for the next generation monitor. Flexible display is thin and flexible, shock-resistant, and can serve in daily life as electronic paper and electronic books. Flexibility is one of major characteristics for flexible display. Therefore, how to measure the strain field of bending for flexible polymer substrate that constitute the flexible display is an important technique. In view of the fact that traditional devices such as strain gages and photoelasticity are not suitable for measure large deformation, this study develops noncontact measurement as the first choice. As a result of today's noncontact measurement technology is set up by complex structure of the optical path, and the environment of measurement is demanding. This study develops an imaging method less susceptible of light effect on the environment, rather than sets up complex devices of noncontact measurement. Using two CCD cameras constructs a three-dimensional computer vision system, which captures images of the sample before and after deformation in the bending test. Based on the digital image correlation, this study compares the displacement vector of any point on the display surface when deformation occurs. The deformation gradient of materials is calculated by the displacement vector, and we can obtain the strains of the bending test for flexible electronic. According to the bending test result of PEN substrate, the strain at the center of sample surface indeed increases with curvature increase.
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Wildy, Stuart James. "Scanning laser doppler vibrometry for strain measurement and damage detection." Thesis, 2012. http://hdl.handle.net/2440/93519.
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Numerous strain measurement and damage detection techniques have been developed over the last century. These techniques include strain gauges, digital image correlation, radiography and ultrasonic inspections. All have various advantages, as well as disadvantages, which make each suited to specific applications. With the development of laser Doppler vibrometry, a number of techniques have been established for non-destructive evaluation, such as the measurement of bending strain, as well as damage detection using kinematic parameters, including displacement and curvature. With recent advancements in laser Doppler vibrometry technology (such as 3D scanning laser Doppler vibrometry for three-dimensional displacement measurements, improved velocity decoders and increased spatial resolution) the door has been opened to develop techniques for measuring surface strain from in-plane displacements, as well as the development of new damage detection techniques based on the fundamental principle of deformation:- the governing differential equation of displacement. The extensive literature review contained in this thesis identified a number of gaps in the field, including the evaluation of the accuracy of quasi-static bending strain measurements using current 1D SLDV technology, the precision of full-field surface strain measurement techniques utilising 3D SLDV, and new detection techniques based on the violation of the governing differential equations of displacement. Thus, the research contained in this thesis focussed on these areas. The first part of this thesis presents an investigation into the use of 1D and 3D scanning laser Doppler vibrometry for non-contact measurement of quasi-static bending strain in beams and surface strain in plates, respectively. The second part presents a new damage detection technique based on the governing differential equations of displacement in beam and plate structures. Two algorithms are developed to determine a violation in the governing differential equations created by either a delamination in a composite beam with out-of-plane displacements, or by a crack in a plate with in-plane displacements.Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2012
Books on the topic "Bending strain measurement"
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F, Harrington, and United States. National Aeronautics and Space Administration., eds. Static test induced loads verification beyond elastic limit. [Washington, D.C: National Aeronautics and Space Administration, 1996.
Find full textBook chapters on the topic "Bending strain measurement"
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Grediac, M., and A. Vautrin. "Measurement of Laminate Bending Elastic Parameters from Non-Uniform Strain Fields." In Mechanical Identification of Composites, 91–98. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3658-7_9.
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Hack, Erwin, and Ann Schumacher. "Espi-Measurement of Strain Components on a Cfrp-Reinforced Bending Beam." In Experimental Analysis of Nano and Engineering Materials and Structures, 723–24. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6239-1_359.
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Bremand, F., and A. Lagarde. "Optical Method of Strain Measurement. Application to Study of Circular Bending of a Beam in the Large Strain Range." In Experimental Stress Analysis, 341–50. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4416-9_38.
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Kohzuki, Yohichi. "Study on Influence of a State of Dopants on Dislocation-Dopant Ions Interaction in Annealed Crystals." In Alkaline Chemistry and Applications [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96395.
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Combination method of strain-rate cycling tests and application of ultrasonic oscillations was conducted for KCl:Sr2+ (0.035, 0.050, 0.065 mol.% in the melt) single crystals at low temperatures. The measurement of strain-rate sensitivity (λ) of flow stress under the application of ultrasonic oscillatory stress provides useful information on the interaction between a mobile dislocation and impurities (Sr2+ ions) during plastic deformation and the variation of λ with stress decrement (Δτ) due to oscillation has stair-like shape: The first plateau place ranges below the first bending point (τp1) at low stress decrement and the second one extends from the second bending point (τp2) at high stress decrement. The value of λ decreases with the Δτ between the two bending points. The τp1 is considered to represent the effective stress due to impurities when a dislocation begins to break-away from the impurities with the help of thermal activation during plastic deformation. Annealing the impure crystal by heat treatment, τp1 decreases obviously at low temperature and the critical temperature Tc, at which τp1 is zero, also becomes slightly smaller. Furthermore, it was investigated whether a change in the state of a small amount of impurities has an influential factor of the flow parameters (e.g., the activation energy, the density of forest dislocations) from the data analyzed in terms of Δτ vs. λ curve.
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Zhao, Hongduo, Songyuan Gu, Jianming Ling, and Yizhou Peng. "Measurement of flexural displacement and strain in bending test based on digital image analysis." In Bituminous Mixtures and Pavements VI, 367–72. CRC Press, 2015. http://dx.doi.org/10.1201/b18538-53.
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"Fatigue of Metals." In Fatigue and Fracture, 147–207. ASM International, 2012. http://dx.doi.org/10.31399/asm.tb.ffub.t53610147.
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Abstract This chapter discusses the factors that play a role in fatigue failures and how they affect the service life of metals and structures. It describes the stresses associated with high-cycle and low-cycle fatigue and how they differ from the loading profiles typically used to generate fatigue data. It compares the Gerber, Goodman, and Soderberg methods for predicting the effect of mean stress from bending data, describes the statistical nature of fatigue measurements, and explains how plastic strain causes cyclic hardening and softening. It discusses the work of Wohler, Basquin, and others and how it led to the development of a strain-based approach to fatigue and the use of fatigue strength and ductility coefficients. It reviews the three stages of fatigue, beginning with crack initiation followed by crack growth and final fracture. It explains how fracture mechanics can be applied to crack propagation and how stress concentrations affect fatigue life. It also discusses fatigue life improvement methods and design approaches.
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"In Situ Curvature Measurements, Strains, and Stresses in the Case of Large Wafer Bending and Multilayer Systems." In III-V Compound Semiconductors, 375–410. CRC Press, 2016. http://dx.doi.org/10.1201/b10390-13.
Full textConference papers on the topic "Bending strain measurement"
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Zhang, Z. T., and J. L. Duncan. "Strain Modeling and Measurement in Tube Bending." In International Congress & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1996. http://dx.doi.org/10.4271/960825.
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Christopherson, Adam, and Young-Hoon Han. "Validation for External Tieback Connector Bending Capacity by Strain Measurement." In ASME 2019 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/pvp2019-93925.
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Abstract Strain gauges provide a convenient and affordable method to accurately measure the strain field for complex systems. Not only do they provide crucial information for predicting the fatigue life of components, but they can also determine the principle stresses which can be used to compare design factors with accepted industry standards. The use of electrical resistance strain gauges for load verification has become an ever-increasing practice in the design of subsea connectors as evidenced by the recent application in the industry guidance API 17TR7 [1]. The design is aided by the development of a Finite Element Analysis (FEA) which is used to predict the load capacities for normal, extreme, and survival conditions. The present work describes the experimental validation of a 18-3/4in 10,000 psi subsea collet connector model by applying linear pattern CEA-06-062UW-350 strain gauges at discrete points along the circumferentially spaced collet segments. The collet segments are the selected components for strain gauge placement because not only are they the primary connecting element between the subsea wellhead and the connector body, but they also only support axial loads. The axial strain of the collet segments in tension were compared at two combined loading cases: maximum bending capacity with and without internal working pressure and found to be in good correlation with the elastic-plastic FEA. The experimentally validated FEA is a crucial tool in determining the connector’s application to project or customer specific load and fatigue requirements and eliminates the need for unnecessary experimentation.
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Ferguson, N. S., and J. B. Carpentier. "The Use of the Laser Vibrometer as an Alternative to Strain Gauges to Measure Bending Strain." In Stress and Vibration: Recent Developments in Measurement and Analysis, edited by Peter Stanley. SPIE, 1989. http://dx.doi.org/10.1117/12.952920.
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Landwehr, Derek, Jim Watts, Daryl Crawmer, and Beth Aperavich. "Instrumented Strain-Gage Measurement for Coating Adhesion During Four-Point Bending." In ITSC2018, edited by F. Azarmi, K. Balani, H. Li, T. Eden, K. Shinoda, T. Hussain, F. L. Toma, Y. C. Lau, and J. Veilleux. ASM International, 2018. http://dx.doi.org/10.31399/asm.cp.itsc2018p0120.
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Abstract ASTM C633 has been an industry standard for determining thermal spray coating adhesion and cohesion strengths for nearly 40 years. The test, however, has several drawbacks that can greatly affect the results. The epoxies used cannot withstand stresses greater than 15,000psi, producing data that may suggest coatings cannot function beyond the epoxy threshold under uniaxial tensile loading, resulting in data that can only be used for general quality control or acceptance testing. Previously published data shows coatings functioning beyond C633 limits, yet there is no standardized test to show true functional stress limitations. A four-point bend test method with an instrumented strain-gage has been used to show coating adhesion well beyond the yield point of the steel substrates and beyond the C633 limits for three materials and thermal spray processes: electric arc sprayed aluminum bronze, plasma sprayed alumina, and HVOF WC/Co/Cr. A strain-gage is applied to a prepared coating surface on a bend bar and loaded under tension or compression. The MTS universal load frame force data is used to calculate the stress at the coating/substrate interface by beam theory equations, allowing for stress and strain vs displacement curves to be generated and directly compared against C633 data for coating adhesion strengths. The resulting data can indicate microscopic coating behavior (cracking, de-bonding) as a result of the test sensitivity and can ultimately be used as design data for the practicing engineer.
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Ozkan, Istemi F., Daryl J. Bandstra, Chris M. J. Timms, and Arthur T. Zielinski. "Employing Visual Image Correlation for the Measurement of Compressive Strains for Arctic Onshore Pipelines." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10952.
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The Arctic onshore environment contains regions of discontinuous permafrost, where pipes may be subject to displacement-controlled bending in addition to high hoop stresses due to the pressurized fluids being transported. Considering the displacement-controlled nature of the deformations, strain-based design methodologies have been developed for permafrost pipelines when they are subject to bending and tension, which limit the longitudinal compressive and tensile strains. The widely accepted methodology in the industry to obtain the compressive strain capacity of line pipes subject to bending is to conduct Finite Element Analysis, incorporating material and geometrical nonlinearity calibrated against benchmark full-scale tests (bend tests) [1,2]. During these tests, compressive strains can be measured by various methods. The seemingly obvious choice is to apply strain gauges along the compression face of the specimen with respect to bending (intrados). This method will provide reasonable results until the compressive strain pattern begins to vary due to the initiation of buckle formation, which typically occurs shortly after yield. In order to measure average compressive strain beyond yield and up to buckling, the method used by C-FER Technologies (C-FER) involves using rotation measurement devices (inclinometers) to calculate the strain change between the most compressive and tensile fibres of the specimen (intrados and extrados, respectively) with respect to the bending direction. This value is then subtracted from the tensile strain gauge readings as measured by the strain gauge(s) located on the extrados of the specimen. The average compressive strain values derived from the inclinometer and extrados strain gauge measurements are based on the assumption that the plane sections remain plane. Recently, five large diameter pipes were bend-tested at C-FER’s testing facility in Edmonton, Alberta. In addition to the compressive strain measurement method used by C-FER described above (C-FER method), a visual image correlation (VIC) camera system was used to survey the strain distribution on the compressive face of the specimens. This paper gives a brief description of the test setup and instrumentation of this test program. The VIC camera setup and measurement technique are described and the overall strain distribution on the bending intrados as measured by the VIC cameras is presented. Strain measured by the VIC system is compared with gauge measurements at local points as well as the average compressive strain behaviour of the specimens obtained through the C-FER method described above. The results show that the VIC system can be a candidate to replace the conventional measurement techniques employed for compressive strain limit testing in support of strain-based design of arctic pipelines.
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Choquette, Jeremie J., Sylvain Cornu, Mohamed ElSeify, and Raymond Karé. "Understanding Pipeline Strain Conditions: Case Studies Between ILI Axial and ILI Bending Measurement Techniques." In 2018 12th International Pipeline Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/ipc2018-78577.
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In-Line inspection (ILI) tools consisting of combined sensor technologies provide a unique opportunity for operators to understand the conditions of pipelines. There is also an additional opportunity to contrast and validate individual sensing techniques against each other when their functionalities and purposes overlap. By using multi-technologies ILI measurements for strain, a pipeline operator can gain further insight into the pipeline strain behavior at any point along the length of the inspection. This paper establishes the relationship between ILI axial strain measurement tool data and conventional geometric strain data obtained from inertial measurement unit (IMU) based on data collected during in-service inspection of a 12″ liquid pipeline. Within any pipeline section, the tool configuration with circumferentially spaced strain sensors allows the use of appropriate analysis techniques to decompose the longitudinal strain into its primary components (axial, bending and out of roundness). The axial strain measurement tool sensing system provides an indirect measurement of bending strain that can be compared to the geometric measurement of bending strain determined from the pipeline trajectory as determined from the IMU analysis. Flexural bending strain resulting from horizontal directional drilling (HDD) is investigated in this paper. Convergences and divergences between the measurement techniques are presented. Data available from different strain technologies mounted on ILI tools offers an opportunity to conduct a comparative study and to provide a better understanding of a pipeline’s strain condition. This paper will present the framework for understanding the different strain measurement technologies and an investigation into the pipeline prior strain history (effects from fabrication, hydrostatic testing and external loads) and their corresponding impact on the material state at the time of inspection.
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Berthold III, John W. "Measurement of axial and bending strain in pipelines using Bragg grating sensors." In Environmental and Industrial Sensing, edited by Brian Culshaw, James A. Harrington, Michael A. Marcus, and Mohammed Saad. SPIE, 2001. http://dx.doi.org/10.1117/12.417396.
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Rogge, Renee D., Scott R. Small, Derek B. Archer, Michael E. Berend, and Merrill A. Ritter. "Validation of Digital Image Correlation Techniques for Strain Measurement in Biomechanical Test Models." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14540.
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Many previous biomechanical studies of bone and bone substitutes have estimated strains in these materials using strain gages. The purpose of this study was to compare digital image correlation (DIC) strain measurements to those obtained from strain gages in order to assess the applicability of DIC technology to common biomechanical testing scenarios. Compression and bending tests were conducted on aluminum alloy, polyurethane foam, and laminated polyurethane foam specimens. Results showed no significant differences in the principal strain values (or the variances) between strain gage and DIC measurements on the aluminum alloy and laminated polyurethane foam specimens. There were significance differences between the principal strain measurements of the non-laminated polyurethane foam specimens, but the deviation from the theoretical results was similar for both measurement techniques. In summary, DIC techniques provide similar results to those obtained from strain gages and also provide full field strain results.
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Bergman, Jason, Ming Liu, and Chris Timms. "Visual Image Correlation Compared to Discrete Instrumentation for Measurement of Compressive Strains for Strain Based Design." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-62676.
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Strain-based design philosophies have been developed to ensure safe pipeline operation through regions of slope instability, seismic activity or discontinuous permafrost while extending the life expectancy of the pipeline in those zones. Strain-based design methodology typically involves a comparison of the strain demand (estimated conservatively using numerical pipe-soil interaction analysis techniques) to the strain capacity (predicted using experimentally benchmarked models). This paper presents a comparison of measurement techniques for laboratory testing of critical compressive strain capacity (CCS). The CCS is defined as the strain coinciding with the peak bending moment, averaged over a gauge length often selected as one pipe diameter across the buckle location. As explored in previous work [1], the three most common methods to measure strain on the specimen intrados, with respect to bending, include 1) direct measurement using strain gauges on the intrados with respect to bending, 2) calculation of CCS from the output of discrete instrumentation (DI) including strain gauges and inclinometers; and 3) direct measurement of surface strains using Visual Image Correlation (VIC) techniques. In 2015 and 2016, the Centre for Reliable Energy Systems (CRES) and C-FER Technologies 1999 Inc. (C-FER) collaborated on a series of full-scale experiments (performed by C-FER) and detailed finite element analysis (FEA) (performed by CRES) intended to assess and understand the effect of various anomalies on the strain capacity of line pipe. To facilitate comparison of the DI strain measurement method and the newer VIC method, these tests were conducted using both methods. The results demonstrate that the VIC technique can provide a more complete measure of the strain field and greater accuracy in cases where uneven strain distributions challenge the assumptions associated with DI methods. High level test data is presented and one test displaying the discrepancy between VIC and DI results is described. Finite element modelling, employed to explore the digression observed between the two strain measurement methods, is also presented and the comparative results of the two strain measurement techniques are discussed.
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Takahama, Tsunemichi, Kazuma Nishimura, Seiichiro Ninomiya, Yoshihiro Matsumoto, and Yutaka Harada. "Development of a Quick and Easy-to-Install Strain Measurement Tool for Both Bending and Torsional Piping Stress Assessment." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63144.
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To assess the stresses on small-bore piping, we have developed a new tool that can be easily installed on a piping surface without adhesive bonding and that measures strains on piping quickly and accurately. This tool, which we call a “strain gauge holder,” is patented in Japan. As the tool can contain four strain gauge rosettes, with each rosette comprising three elements, the longitudinal strains and sheer strains can be measured synchronously at any four points precisely 90 degrees apart, with one point in each quadrant. By mockup testing, we confirmed that the measured bending and torsional strains by the holder were almost equivalent to the measured strains by the bonded gauges with adhesive, and that the holder made it possible to synchronously measure all of the strains resulting from the moment of force acting in three axes on the piping by measuring the bending and torsional strains in each quadrant. The strain gauge holder is expected to significantly reduce the pre- and post-working time required for strain measurement and stress assessment of piping in real plants.