• Title/Summary/Keyword: 구조강도평가

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Freezing-Thawing Resistance of Fiber Reinforced Polymers in Strengthening RC Members (구조보강용 FRP 복합체의 동결용해 저항성 평가 연구)

  • You, Young-Chan;Choi, Ki-Sun;Kim, Keung-Hwan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.1
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    • pp.182-189
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    • 2010
  • The strengthening performance of FRPs(Fiber Reinforced Polymers) is directly affected by the environmental conditions such as freezing-thawing and moisture because FRPs are usually bonded on the concrete surface. It is, therefore, strongly required to evaluate a durability of bond between FRPs and concrete as well as FRP materials itself. The freezing-thawing resistance of FRPs is evaluated in this study with the variables of freezing-thawing conditions, types of FRP and freezing-thawing cycles. From the test results, it is found that tensile strength and pull-off strength of CFRP are not affected by the freezing-thawing. On the other hands, those of GFRP show a little degradation because of continuous water immersion during thawing process. But, cautions are needed on the bond durability between FRPs and concrete in case of continuous water supplying from adjacent to the concrete.

Hull Strength Evaluation of Dissemination 12ft Bass Fishing Boat Using FEA (보급형 12피트 배스 낚시보트의 유한요소해석을 통한 선체강도평가)

  • Oh, Young-Cheol;Ko, Jae-Yong;Chung, Se-Yun;Choi, Jeong-Hwan;Kim, Hyeon-Jin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2012.06a
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    • pp.225-226
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    • 2012
  • Recently, In the domestic is used mainly fiberglass reinforced plastic(GRP) and is built for maritime leisure vessel & structures. but it less attention is insufficient for ship of structural strength assessment of maritime leisure vessel. Therefore, The structural strength evaluation suitable for the domestic situation formulate and is applied to domestic regulations of "Guidance for Recreational Crafts" of Korea register of shipping(KR) & "Reinforced plastic line structure standards" of Ministry of Land, Transport and Maritime Affairs. the structural design and finite element analysis(FEA) to ensure the reliability.

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The Evaluation of Strength for the Corner Block Structure in the LNG Tank using Sloshing Pressure of the Scaled Tank (모형수조 슬로싱 하중을 이용한 LNG 탱크 코너블럭(Corner Block) 구조물의 구조강도 평가)

  • Park, Jun Hyeong;Park, Si Jong;Kim, Seong Hoon;Choi, Jae Min;Jun, In Ki
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.5
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    • pp.327-333
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    • 2013
  • The purpose of this study is to predict sloshing pressure of a actual tank by using measured pressure in scaled down tank and to evaluate with structural strength of LNG Corner Block. For this purpose, we performed sloshing analysis about 138K class tank by using Ansys CFX program, and were measured both average pressure and maximum peak pressure according to scaled tank ratio. Also, measured pressure was converted to pressure of the actual tank by Froude scale law, and we conducted the evaluation of structural strength about the conner block of actual size KC-1.

Evaluation of Limit Strength for Steel Cable-Stayed Bridgesusing Various Cable Elements (다양한 케이블 요소를 이용한 강사장교의 극한강도 평가)

  • Song, Weon-Keun;Rhee, Jong Woo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.5
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    • pp.115-121
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    • 2006
  • This paper deals with the influence of behavior of a variety of cable elements on the limit strength of steel cable-stayed bridges. The softening plastic-hinge model, which is represented in this study for the limit strength evaluation of the example bridge, considers both geometric and material nonlinearites. Geometric nonlinearity of beam-column members are accounted by using stability function, and material nonlinearity - by using CRC tangent modulus and parabolic function. Cable sag effect is considered for cable members. The result of this study shows that the limit strength of the example bridge using the equivalent of elasticity for truss straight elements is smaller than those using the cable or the catenary elements.

손상된 파이프의 구조 안전성 평가

  • 박재학
    • Bulletin of the Korean Institute for Industrial Safety
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    • v.2 no.1
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    • pp.34-40
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    • 2002
  • 화학설비나 산업설비 또는 국가 기간 설비에서 파이프(pipe)는 중요한 위치를 차지하고 있으며 파이프의 파열은 그대로 대형 사고나 설비 가동의 중단으로 연결되는 경우가 많다. 따라서 파이프의 구조건전성을 유지하는 것은 안전의 확보와 생산 설비의 효율적 운용을 위하여 긴요하다. 파이프 재료 내부에는 재료 제작 시, 또는 파이프 제작 시 발생된 결함이나 사용 중 부식이나 피로 등의 영향으로 생성된 결함이 존재한다. 이러한 결함은 파이프의 강도를 낮추게 되고, 파이프의 잔류강도가 사용압력보다 낮아지게 되면 파이프가 파열하게 된다. 따라서 본 글에서는 파이프에 균열이 존재하거나 손상된 경우의 구조안전성 평가를 위하여 필요한 해석방법에 대하여 살펴본다.(중략)

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Evaluation of Flexural Bond Performance of Hybrid Concrete Repair Materials (하이브리드 콘크리트 보수재료의 휨부착 성능평가)

  • Kim, Gyeong Tae;Kim, Sang Jun;Park, Hong Gi;Choi, Young Cheol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.6
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    • pp.176-181
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    • 2018
  • Concrete structures are degraded physically and chemically due to various reasons after construction. Because the deterioration of concrete structure reduces the service life, reasonable repair and maintenance techniques are needed. Recently, in order to efficiently repair concrete structures, many researches on hybrid repair materials having improved adhesion performance have been carried out actively. In this study, we developed a hybrid repair material containing rapid hardening cement, PVA powder, nylon fiber, and latex to improve adhesion and water-tightness of existing concrete. The compressive strength, drying shrinkage and the adhesion strength test were carried out to evaluate the performance of the repair material. In addition, the flexure bond performance was evaluated before and after repair. From the results, the bending strength was 110% ~ 150% in all specimens except for the specimen containing only the rapid hardening cement, and all the specimens behaved with the existing concrete in the crack pattern generated by the bending strength.

Seaming Behaviors Interpretation of Geotextile Tube (지오텍스타일 튜브의 봉합거동에 관한 연구)

  • Jeon, Han-Yong;Yuu, Jung-Jo;Chang, Yong-Chai
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1593-1603
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    • 2008
  • 지오텍스타일 튜브의 봉합거동에 대한 이론연구와 실험을 수행하여 효율적인 봉합구조와 합리적인 설계 강도의 결정을 위한 방안을 고찰하였다. 수행 실험은 지오텍스타일 튜브 제품을 형성하기 위해 사용되는 봉합사에 대한 해수조건을 고려하여 내구성 평가와 봉합강도를 개선시키기 위해 다양한 봉합형태에 따른 봉합강도를 평가하여 고찰하였다. 지오텍스타일 튜브의 장기설계강도의 결정에서 지오텍스타일 자체의 강도 감소인자 뿐 아니라 봉합부에서의 여러 감소인자들을 고려하여야 하며 정확히 평가할 수 있는 시험규격의 정립이 요구된다. 봉합사의 강도가 유사한 경우 봉합형태가 봉합강도에 주요한 영향을 미치며, 봉합사의 봉합 후 긴장상태도 실험 중에 영향을 미치는 것으로 확인되었다.

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Evaluation of Wet-Mixed High Strength Sprayed Polymer Mortar for Fire Resistance (내화용 고강도 습식 스프레이 폴리머 모르타르의 화재 저항성 평가)

  • Won, Jong-Pil;Choi, Seok-Won;Park, Chan-Gi;Park, Hae-Kyun
    • Journal of the Korea Concrete Institute
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    • v.18 no.4 s.94
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    • pp.559-568
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    • 2006
  • The purpose of this study is to evaluate the mechanical performance and fire resistance of wet-mixed high strength sprayed polymer-modified mortar in order to protect tunnel lining system which are in the event of fire disaster. Since the current commercial fire-resistant materials reproduce the low strength issue of mortar, this study aims to provide an enhanced fire-resistant mortar with a proper strength. Normally, a large temperature gradient phenomenon arise in the vicinity of free surfaces which are fully exposed in the event of persistent flame. Thereby, the determination of optimal cover depth of wet-mixed high strength sprayed polymer-mortar(WHSPM) is important for fire-resistance of tunnel lining system. With comparison of current commercial fire-resistance materials and WHSPM, the experimental result of WHSPM shows the better fire-resistant performance than the others. In addition, the cover limitation should be controlled by minimum 4cm depth in order to avoid fire-induced damage.

Failure Load Prediction of the Composite Adhesive Joint Using the Damage Zone Ratio (파손영역비를 이용한 복합재 접착 체결부의 파손강도 예측)

  • Lee, Young-Hwan;Ban, Chang-Su;Choi, Jin-Ho;Kweon, Jin-Hwe
    • Composites Research
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    • v.21 no.4
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    • pp.22-28
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    • 2008
  • The composite joint has become an important research area because the structural efficiency of a structure with a joint is determined by its joints rather than by its basic structure since the joints are often the weakest areas in composite structures. In this paper, the strengths of adhesive joints consisting of metal and composites were predicted and tested by the maximum strain theory and damage zone theory. Nonlinear finite element analyses of adhesive Joints considering the material nonlinearity of the adhesive layer were performed. From the tests and analyses, the strengths of the adhesive joints could be predicted to within 22.2% using the damage zone ratio.

Structural Performance of Column-Slab Connection in Flat Plate System Using High Strength Concrete (고강도 콘크리트를 사용한 플랫 플레이트 구조의 기둥·슬래브 접합부 구조성능)

  • Kim, Hyong-Kee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.1
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    • pp.97-105
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    • 2006
  • The reinforced concrete flat plate system provides architectural flexibility, clear space, reduced building height, simple formwork, which consequently enhance constructibility. One of the serious problem in the flat plate system is brittle punching shear failure due to transfer of shear force and unbalanced moments in column-slab connection. Since the use of high strength concrete recently has become in practice for reinforced concrete structures, it is highly desired to establish the structural design method for flat plate construction using high strength concrete. In this paper, interior column-slab connection constructed with high strength concrete were tested under lateral and gravity loads to evaluate their strength and behavior. The test parameters were slab reinforcement ratio and the gravity load levels.