• Title/Summary/Keyword: 휨하중

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Bending Moment Characteristics of Flexibly Supported Infinite Beam Subjected to an Axial Force and a Moving Load (이동하중(移動荷重)과 축하중(軸荷重)이 작용(作用)하는 유연(柔軟)한 기초(基礎)위에 지지(支持)된 무한(無限)보의 휨모멘트 특성(特性))

  • Hong, Dong Pyo;Kim, Kwang Sic
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.2 no.3
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    • pp.15-22
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    • 1982
  • This paper presents analytic bending moment solution and resonance diagrams for a uniform beam of infinite length subjected to anaxial force and moving transverse load. Solutions are obtained that are time invariant in a coordinate system moving with the load velocity. The supporting foundation includes damping effects. The influences of the axial force, damping coefficient and load velocity on the beam response are studied. The limiting case of no damping and critial damping are also investigated. The profiles of the mement of the beam is shown graphically for several values of the load speed, the axial force and damping parameters.

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A Theoretical and Experimental Investigation on the Fatigue Strength and Fatigue Reliability Analysis of Concrete (콘크리트의 피로강도 및 피로신뢰성해석에 관한 이론 및 실험연구)

  • Oh, Byung Hwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.4
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    • pp.113-119
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    • 1985
  • The fatigue strength and reliability of concrete subjected to ftexural loading is investigate. The concrete beam specimens are prepared and tested in four-point flexural loading in which the bottom fiber stress varies from zero to a predetermined maximum stress. The S-N curves are generated from these test results and an equation is obtained by regression analysis to predict the flexural fatigue strength of concrete. A method is presented to perform the probabilistic analysis on the flexural fatigue of concrete. It is shown that the Weibull distribution has physically more convincing features and may be appropriate to describe the fatigue behavior of concrete.

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Stress Analysis of Cold-Formed Steel Beams Considering Local Buckling Effects (국부좌굴을 고려한 냉간성형 ㄷ 형강보의 응력해석)

  • Jeon, Jae Man;Hyun, Ja Young;Lee, Jae Hong
    • Journal of Korean Society of Steel Construction
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    • v.16 no.1 s.68
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    • pp.51-60
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    • 2004
  • The stress analysis of cold-formed channel section steel beams under transverse load was conducted. The local buckling effect was included in the analysis using effective area concept. The proposed analytical model is capable of predicting accurate normal stress in the beam due to various behaviors including biaxial bending and warping. It was found to be appropriate for predicting stresses as well as deflection in the beam. A finite element model was developed to solve the analytical model.

Elastic Stability of Thin-Walled Arches subjected to Uniform Bending - Linear Bending Normal Strain Distribution -

  • Ryu, Hyo-Jin;Lim, Nam-Hyoung;Lee, Chin-Ok
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.2
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    • pp.11-15
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    • 2009
  • This paper is concerned with the elastic buckling of thin-walled arches that are subjected to uniform bending. Nonlinear strain-displacement relations with the initial curvature are substituted into the second variation of the total potential energy to obtain the energy equation including initial curvature effects. The approximation for initial curvature effects that the bending normal strain distribution is linear across the cross section is applied consistently in the derivation process. The closed form solution is obtained for flexural-torsional buckling of arches under uniform bending and, it is compared with the previous theoretical results.

Behavior of RC Beams Strengthened with Carbon Fiber SheetsUnder Repeated Loading (단조 반복하중 하의 탄소섬유시트 보강 RC보의 거동에 관한 연구)

  • Park, Jeong Yong;Kim, Seong Do;Cho, Baik Soon;Cheung, Jin Hwan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.4
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    • pp.183-193
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    • 2006
  • This study deals with the response of reinforced concrete beams strengthened with carbon fiber sheets. Test beams are subjected to static loading and repeated loading. Based on the static test results of the RC beams strengthened with carbon fiber sheets, repeated loading tests are performed. The variables of repeated loading test are composed of the number of carbon fiber sheets, the existence of U-shaped band at the end for anchoring, and loading rate of repeated loading, etc. Test results show the flexural behavior, the characteristics of strength, the characteristics of ductility, the change of flexural rigidity, and the amount of energy loss of RC beams under monotonic incremental loading and repeated loading. The failure strain of carbon fiber sheets is also estimated under repeated loading. From the experimental results, this work presents a basis of the data needed to analyze and design the static and dynamic flexural response of RC beams strengthened with carbon fiber sheets.

Effect of Bond Length and Web Anchorage on Flexural Strength in RC Beams Strengthened with CFRP Plate (부착길이와 복부정착이 CFRP판으로 보강된 RC 보의 휨 보강효과에 미치는 영향)

  • 박상렬
    • Journal of the Korea Concrete Institute
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    • v.14 no.5
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    • pp.645-652
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    • 2002
  • This paper presents the flexural behavior and strengthening effect of reinforced concrete beams bonded with carbon FRP plate. Parameters involved in this experimental study were plate bond length and sheet web anchorage length. Test beams were strengthened with FRP plate on the soffit and anchored with FRP sheet on the web. In general, strengthened beams with no web anchorage were failed by concrete cover failure along the longitudinal reinforcement. On the other hand, strengthened beams with web anchorage were finally failed by delamination shear failure within concrete after breaking of CFRP sheet wrapping around web. The ultimate load and deflection of strengthened beams increased with an increased bond length of FRP plate. Also, the ultimate load and deflection increased with an increased anchorage length of FRP sheet. Particularly, the strengthened beams with web anchorage maintained high ultimate load resisting capacity until very large deflection. The shape of strain distribution of CFRP plate along beam was very similar to that of bending moment diagram. Therefore, an assumption of constant shear stress in shear span could be possible in the analysis of delamination shear stress of concrete. In the case of full bond length, the ultimate resisting shear stress provided by concrete and FRP sheet Increased with an increase of web anchorage length. In the resisting shear force, a portion of the shear force was provided by FRP anchorage sheet.

Design of Ground Floor Slab According to the Method for Evaluating the Tensile Performance of Steel Fiber Reinforced Concrete (강섬유 보강 콘크리트 인장성능 평가방법에 따른 지반 바닥슬래브의 설계)

  • Lee, Jong-Han;Cho, Baik-Soon;Cho, Chang-Oh
    • Journal of the Korea Concrete Institute
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    • v.28 no.1
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    • pp.95-104
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    • 2016
  • Flexural strength of concrete ground slab reinforced with steel fiber is evaluated using the equivalent flexural strength ratio of steel fiber reinforced concrete based on the yield line theory. Recently, the European standard specifies that the tensile performance of the steel fiber reinforced concrete be evaluated directly from the residual flexural strength after the cracking of concrete. Thus, in the study, an experiment was carried out to evaluate the conventional equivalent flexural strength ratio and the residual flexural strength of the steel fiber reinforced concrete. Then the design flexural strength was investigated according to the location of a point load, based on the ratio of the radius of contact area of the load to the radius of relative stiffness. Design flexural capacity obtained from ACI 360R-10 was smaller than that from TR 34 (2003 & 2013). In addition, TR 34 (2013), which evaluates the design flexural capacity based on the residual flexural strength, showed slightly smaller value than TR 34 (2003).

Analytical Study on the Flexural Strength of CFS Reinforced Concrete Beams under Service Loads (사용하중을 받는 RC보의 탄소섬유 휨 보강에 관한 해석적 연구)

  • Yoon, Tae-Ho;Kang, Kyung-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.8
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    • pp.3745-3751
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    • 2011
  • In this study flexural strength of damaged concrete beams reinforced by CFS is analysed. Nonlinear section analysis is used to include stress status of tension bars and compressive concrete under loads acting on the original member at the time of strengthening. Calculated flexural strength is compared with Sin-Hong formula which is frequently used in CFS reinforcement design. Nonlinear analysis with variation of the number of strengthening CFS, the ratio of tensile reinforcement, the ratio of section dimension shows that the flexural strength of CFS reinforced beams much depends on reinforcing stage. From the result of this analysis, the flexural strength of CFS reinforced concrete beam is reduced according to the magnitude of pre-loaded service loads.

A Study on the Design Bending Moments of Long Span Decks with KL-510 Load (KL-510 하중을 적용한 장지간 바닥판의 설계휨모멘트에 관한 연구)

  • Chung, Chulhun;Lee, Hanjoo;Joo, Sanghoon;An, Hohyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.3
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    • pp.375-384
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    • 2016
  • In the current Korea highway bridge design code (KHBDC), the criteria of concrete bridge decks are mainly based on short span decks of steel plate girder bridge, there are very little the specific criteria of long span decks in the twin steel plate girder bridge. Therefore, to put more rational and practical design criteria of the long span decks on the code, the complements of the related criteria are required in the current design code. This paper proposed the design bending moments of decks with 6.0~12.0m span for KL-510 load in direction to bridge (longitudinal direction) and perpendicular direction to bridge (transverse direction). The effects of orthotropic concrete decks, stiffness of steel girders and multiple lane loading factors (MLLF) were reflected in the design bending moments. The proposed design bending moments were compared to the design bending moments with DB-24 load.

Flexural Performance of Reinforced Concrete Beams with Recycled Aggregates Suffering from Sustained Load (지속하중을 경험한 철근콘크리트 보의 골재 종류에 따른 휨거동 특성)

  • Ji, Sang-Kyu;Yun, Hyun-Do;Kim, Sun-Woo;Lee, Eon-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.5
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    • pp.135-143
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    • 2007
  • This paper presents results of an experimental study designed to investigate the effect of sustained load on the flexural performance of reinforced recycled aggregate concrete beams. In this experimental program, three beams with recycled aggregate replacement percentages(natural 100%, recycled coarse aggregate 100%, recycled fine aggregate 50%) were tested up to failure after sustained loading($0.5M_n$) for one year. The experimental results showed that reinforced concrete beams using recycled aggregate(water absorption : 1.86~3.64%) concrete showed the same flexural performance as that of natural aggregate concrete beam. Current the ACI code underestimated experimental obtained ultimate flexural strength of beams irrespective of usage of recycled aggregates.