• Title/Summary/Keyword: Deflection test

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Flexural behavior of concrete beams reinforced with CFRP prestressed prisms

  • Liang, J.F.;Yu, Deng;Yu, Bai
    • Computers and Concrete
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    • v.17 no.3
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    • pp.295-304
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    • 2016
  • An experimental investigation on the behaviour of concrete beams reinforced with various reinforcement, including ordinary steel bars, CFRP bars and CFRP prestressed concrete prisms(PCP). The main variable in the test program was the level of prestress and the cross section of PCP.The modes of failure and the crack width were observed. The results of load-deflection and load-crack width characteristics were discussed. The results showed that the CFRP prestressed concrete prisms as flexural reinforcement of concrete beams could limit deflection and crack width under service load and PCP can overcome the serviceability problems associated with the low elastic modulus/strength ratio of CFRP.

Development of Measuring Data System of Reinforced Concrete Beam Under Cyclic Loading Using Fiber Bragg Grating Sensors (FBG센서를 이용한 반복하중을 받는 RC보의 계측 시스템 개발)

  • Kwak Kae-Hwan;Jang Hwa-Sup;Jung Hyun-Soo;Yang Dong-Oun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.440-447
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    • 2005
  • In this study, strain measurement and its applicability to estimated deflection curve using fiber bragg grating sensors was conducted. For this purpose, reinforced concrete beams were made and sensors were attached both on the surface of the beams and inside steel. Two types of sensors were used to detect strain on the beams and steel : fiber bragg grating sensors, electric resistance strain sensors. So fatigue test is done with measuring strain of specimen. In addition, this experiments estimates the optimum deflection curve that converts strain curve data measured by FBG sensors into deflection.

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A Study of Machining Error Due to Tool Deflection in Micro Endmilling (마이크로 엔드밀링시 공구 변형이 가공오차에 미치는 영향에 관한 연구)

  • Seo, Tae-Il;Sohn, Jong-In;Lee, Hak-Yong
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.18 no.3
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    • pp.294-299
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    • 2009
  • Micro end-milling has been becoming an important machining process to manufacture a number of small products such as micro-devices, bio-chips, micro-patterns and so on. Many related researches have given grand effects to micro end-milling phenomenon, for example, micro end-milling mechanism, cutting force modeling and machinability. This paper strongly concerned actual problem, micro tool deflection, which causes excessive machining errors on the workpiece. Machining error were predicted and measured through a series of test micro cutting and analysis of their SEM images and FEM analysis. Experiments are carried out to validate the approaches.

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Process Design of Shaft Considering Effect of Preform and Eccentric Load on Cold Forging Product in Multistage Former of Horizontal Type (수평식 냉간 다단포머에서 예비성형체와 편심하중을 고려한 Shaft의 성형공정설계)

  • Park S. S.;Lee J. M.;Kim B. M.
    • Transactions of Materials Processing
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    • v.14 no.1 s.73
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    • pp.57-64
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    • 2005
  • This study deals with the cold forging process design for shaft in the main part of automobile motors with rectangular deep groove. In forging process, the accuracy and die lift is very important because it have influence on reduction of the production cost and the increase of the production rate. Therefore, it is necessary to develop the manufacturing process of shaft by cold forging., process variables are the cropped face angle of billet and the eccentric load of punch. The former is derived from cropping test, the latter is occurred by clearance between container and preform. Also, grooved preform select the process variable for decrease in punch deflection. We investigate that a deflection of punch and a deformation of preform to every process variables. Through this investigation, we suggest the optimal preform and process design, expect to be improved the tool life in forging process.

Analysis and prediction of ultimate strength of high-strength SFRC plates under in-plane and transverse loads

  • Perumal, Ramadoss;Palanivel, S.
    • Structural Engineering and Mechanics
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    • v.52 no.6
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    • pp.1273-1287
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    • 2014
  • Plates are most widely used in the hulls of floating concrete structures, bridge decks, walls of off-shore structures and liquid storage tanks. A method of analysis is presented for the determination of load-deflection response and ultimate strength of high-strength steel fiber reinforced concrete (HSSFRC) plates simply supported on all four edges and subjected to combined action of external compressive in-plane and transverse loads. The behavior of HSSFRC plate specimens subjected to combined uniaxial in-plane and transverse loads was investigated. The proposed analytical method is compared to the physical test results, and shows good agreement. To predict the constitutive behavior of HSSFRC in compression, a non-dimensional characteristic equation was proposed and found to give reasonable accuracy.

Microphone-Based Whisker Tactile Sensors Modeling Rodent Whiskers (쥐 수염 센서를 모델로 하는 수염 촉각 센서 연구)

  • Baek, Seung-Hun;Kim, Dae-Eun
    • The Journal of Korea Robotics Society
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    • v.4 no.1
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    • pp.34-42
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    • 2009
  • Rodents, specially rats, can recognize distance and shape of an object and also pattern of the textures by using their whiskers. Mechanoreceptors surrounding the root of whisker in their follicle measure deflection of the whisker. Rats can move their whisker back and forth freely. This ability, called active whisking or active sensing, is one of characteristics of rat behaviours. Many researches based on the mechanism have been progressed. In this paper, we test a simple and accurate method based on deflection of the whisker: we designed biomimetic whiskers modeling after a structure of follicle using the microphone. The microphone sensor measures a mechanical vibration. Attaching an artificial whisker beam to the microphone membrane, we can detect a vibration of whisker and this can show the deflection amount of whisker indirectly.

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On the post-buckling behaviour of plates under stress gradient

  • Bedair, Osama K.
    • Structural Engineering and Mechanics
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    • v.4 no.4
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    • pp.397-413
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    • 1996
  • In this paper the elastic post-buckling behaviour of plates under non-uniform compressive edge stress is investigated. The compatibility differential equations is first solved analytically and then an approximate solution of the equilibrium equation is obtained using the Galerkin method. Explicit expressions are derived for the load-deflection, ultimate strength and membrane stress distributions. Analytical effective width formulations, based on the characteristics of the stress field of the buckled plate, are proposed for this general loading condition. The predicted load-deflection expression is compared with independent test results. Results are also presented detailing the load-deflection behaviour and stress distribution for various aspect ratios.

An Experimental Study on the Load Carrying Capacity and Deformation Properties of Steel Fiber Reinforced Concrete Slab (강섬유보강 콘크리트 슬래브의 내력 및 변형특성에 관한 실험적 연구)

  • 박승범;조광연;신동기;장석호;김부일
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.327-332
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    • 1997
  • This study is aimed to investigate the effect of load and deflection on steel fiber reinforced concrete slab. Slabs were made with Hooked and Straight types steel fiber and compared a change of steel fiber contents and fiber types. Test were carried out to evaluate he first crack load, maximum load and deflection of slab. At the result, the first crack load, maximum load and energy absorption capacity were increased remarkably as steel fiber contents wee increased. And we found that the deflection of slab at same load ere decreased as steel fiber contents were increased, too. As the aspect ration was increased, the first crack load, maximum load and energy absorption capacity were increased.

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Operation Deflection Shapes Analysis for Vibration Reduction of ATM Case (ODS 해석에 의한 ATM 케이스 진동 저감)

  • Shin, Bum-Sik;Lee, Seung-Mock;Kim, Do-Hyun;Choi, Yeon-Sun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.232-237
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    • 2006
  • Operation deflection shapes(ODS) is defined as a motion of structure at particular frequency. The ODS is eligible to show any types of structural motions while the modes supply solutions only to linear and stationary motion. The principal vibration source of an auto teller machine(ATM) case was occurred due to resonance which was found by modal analysis. To reduce the vibration of ATM case, the motion of the case was visualized using ODS analysis, which can suggest how to modify the structure. As a result the vibration of the ATM case was greatly reduced with a stiffening bar between the opposite plates.

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Structural Monitoring of two Korean Traditional Timber Houses

  • Kim, Yeong-Min
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.754-755
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    • 2015
  • In this research, moisture contents and roof deflection of two test-bed Korean traditional timber houses, Hanoks, were monitored. The monitored houses are consisted of two types of Hanoks. One is a one-story traditional Hanok built by traditional construction method, and the other is a two-storied new-styled Hanok built by modernized construction method. The monitoring has been carried out for about thirty months. The moisture contents and roof deflections were analyzed and compared. The moisture contents of the traditional Hanok built by raw wood were somewhat higher than that of the new-styled Hanok built by glued structural wood. The mean vertical deflection of angle rafters of traditional Hanok is about twice more than that of the new-styled Hanok.

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