• Title/Summary/Keyword: 인장거동

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Compressive and Tensile Behavior of Polyetylene Fiber Reinforced Composite According to Silica Sand and Fly Ash (규사 혼입과 플라이애쉬 혼입에 따른 폴리에틸렌 섬유보강 복합재료의 압축 및 인장거동)

  • Kwon, Seung-Jun;Kang, Su-Tae;Choi, Jeong-Il;Lee, Bang-Yeon
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.1
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    • pp.25-30
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    • 2016
  • The purpose of this study is to investigate experimentally the effect of reinforcement of polyetylene fiber, inclusion of silica sand, and replacement of cement with fly ash on the compressive and tensile behavior of fiber reinforced composite. Five types of mixture proportions were determined and compressive strength and uniaxial tension tests were performed. Test results showed that strength, ductility, and control of cracking were improved by the reinforcement of fiber. Although the strength was improved by the inclusion of dried silica sand, the ductility was reduced and the crack width was increased. On the other hand, the increase of ductility, the decrease of crack width, and the decrease of strength were observed by the replacement of cement with fly ash.

Measurement of Electrical Resistance Method in Characterizing the Slip ratio of Carbon fiber/Matrix at the Interface (전기저항 측정법을 이용한 탄소섬유/기지 간 계면에서의 섬유 미끌림 정도 측정방법)

  • Kwon, Dong-Jun;Wang, Zuo-Jia;Gu, Ga-Young;Park, Joung-Man
    • Composites Research
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    • v.25 no.6
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    • pp.205-210
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    • 2012
  • The single carbon fiber tensile test was performed with electrical resistance measurement. Tensile property of single carbon fiber which accompanied by the relationship between the electric resistance and the strain was investigated. Since the collected data showed a linear relationship between them, the coefficient of fiber slip ratio (FSR) was obtained by computation. The fragmentation specimen (FS) was tested under tensile loading, and the single carbon fiber broke first due to the stress transferring form matrix to reinforcing fiber. The stress distribution of carbon fiber could be observed via the electrical resistance change. Slipping between carbon fiber and matrix was predicted based on the fragmentation test results, and the FSR was used to evaluate interfacial adhesion comparatively. The large FSR indicated poor interfacial bonding. Work of adhesion between carbon fiber and matrix was measured to verify the FSR method, and two results exhibited a consistent conclusion.

Tensile Behavior of Concrete-Filled Square Steel Tubular Column-Beam Flange Connections with Stiffeners (강관 보강형 충전 각형강관 기둥-보 플랜지 접합부의 인장거동에 관한 실험적 연구)

  • Yoo, Yeong Chan;Kang, Hyun Sik;Moon, Tae Sup
    • Journal of Korean Society of Steel Construction
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    • v.13 no.1
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    • pp.1-8
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    • 2001
  • The purpose of this study is to examine the utility of concretefilled steel tubular column to H-beam connections with tubular stiffener. As a preliminary step. a tensile experiment was undertaken to scrutinize characteristics of the structural behavior that take place between beam flanges and column with tubular stiffener. A total of 4 types of experimental settings were developed as tabular stiffeners are made up 9, 18, and 27 mm of thickness and 50 and 80 mm of height respetively Along with the overall load subsequently the degree of displacement and strain were recorded. Based on the yield line theory results of this of this study were evaluated and further critically reviewed the applicability of the strength formula. This study found that collapse mechanism was emerged on the beam flange as reinforcing tabular stiffeners Complementary studies of this sort, including numerical analyses should be undertaken in order to develope specific design critera.

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Tensile Behavior of Stud Bolt Connections (스터드 볼트 접합부의 인장 거동에 관한 연구)

  • 이태석;김승훈;서수연;이리형;홍원기
    • Journal of the Korea Concrete Institute
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    • v.13 no.4
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    • pp.321-328
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    • 2001
  • This paper presents the tensile behavior of stud connections installed between reinforced concrete and steel members. Eight specimens are tested to verify the factors influencing the tensile behavior of the connection. Major variables considered in the test are the reinforcement ratios of concrete member and connection details. Test results indicate that the reinforcing bars near stud bolts contribute to the increase of the tensile strength of the member as well as to the reduction of brittle failure. It is shown that C-type or U-type connection has relatively high ductility. From the evaluation on the tensile strength of test results including those of peformed by previous researchers, it was shown CCD (Concrete Capacity Design) method overestimated the strength. In this paper, the reduction factor of 0.75 ø instead of ø is suggested for design purpose of the stud connection.

Compressive Strength and Tensile Behavior of Ultra-High Performance Concrete and High-Ductile Cementless Composite (초고성능 콘크리트와 고연성 무시멘트 복합재료의 압축 및 인장성능)

  • Choi, Jeong-Il;Park, Se Eon;Lee, Bang Yeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.3
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    • pp.69-75
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    • 2017
  • Ultra-high performance concrete and high ductile cementless composite are considered as promising construction materials because those exhibits higher performance in terms of high strength and high ductility. The purpose of this study is to investigate experimentally the compressive strength and tensile behavior of ultra-high performance concrete and high ductile cementless composite. A series of experiments including density, compressive strength, and uniaxial tension tests were performed. Test results showed that the compressive strength and tensile strength of alkali-activated slag based high ductile cementless composite were lower than those of ultra-high performance concrete. However, the tensile strain capacity and toughness of alkali-activated slag based high ductile cementless composite were higher than those of ultra-high performance concrete. And it was exhibited that a high ductility up to 7.89% can be attainable by incorporating polyethylene fiber into the alkali-activated slag based cementless paste.

Fatigue Crack Growth Behavior of a Magnesium-Based Composite (마그네슘 금속복합재의 피로균열거동해석)

  • Kim, Doo Hwan;Park, Yong Gul;Kim, Sung Hoon;Han, Suk Kyu
    • Journal of Korean Society of Steel Construction
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    • v.9 no.4 s.33
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    • pp.515-521
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    • 1997
  • The effects of heat treatment and fiber orientation on tensile strength and fatigue behavior were studied in a continuously reinforced. magnesium-based composite Following an earlier TEM investigation, specimens were thermally aged to modified the interfacial zone between the alumina fibers and the magnesium alloy matrix. From the tensile experimental results, the ultimate tensile strength of the aged specimens were lower than that of the as-fabricated due to weak fiber-matrix interfacial strength with chemical reaction during the thermal processing. The fatigue crack growth experiments were conducted with specimens having the fiber orientation normal to the crack growth direction (longitudinal) and also specimens with the fibers oriented parallel to the crack growth direction(transverse). A comparison of the fatigue crack growth behavior indicates that aged longitudinal specimens are more resistant to fatigue crack growth the as-fabricated longitudinal specimens. Conversely, as-fabricated transverse specimens are more resistant to fatigue crack growth than aged transverse specimens.

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Analytical Study on Flexural Behavior of Alkali-Activated Slag-Based Ultra-High-Ductile Composite (알칼리활성 슬래그 기반 초고연성 복합재료의 휨거동 해석)

  • Lee, Bang Yeon
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.7 no.2
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    • pp.158-165
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    • 2019
  • The purpose of this study is to investigate analytically the flexural behavior of beam reinforced by an alkali-activated slag-based fiber-reinforced composite. The materials and mixture proportion were selected to manufacture an alkali-activated slag-based fiber-reinforced composite with high tensile strain capacity over 7% and compressive strength and tension tests were performed. The composite showed a compressive strength of 32.7MPa, a tensile strength of 8.43MPa, and a tensile strain capacity of 7.52%. In order to analyze the flexural behavior of beams reinforced by ultra-high-ductile composite, nonlinear sectional analysis was peformed for four types of beams. Analysis showed that the flexural strength of beam reinforced partially by ultra-high-ductile composite increased by 8.0%, and the flexural strength of beam reinforced fully by ultra-high-ductile composite increased by 24.7%. It was found that the main reason of low improvement in flexural strength is the low tensile strain at the bottom of beam. The tensile strain at bottom corresponding to the flexural strength was 1.38% which was 18.4% of tensile strain capacity of the composite.

Crack Width Control and Flexural Behavior of Continuous Composite Beams (연속합성보의 균열폭 제어와 휨거동 평가)

  • Shim, Chang Su;Kim, Hyun Ho;Yun, Kwang Jung
    • Journal of Korean Society of Steel Construction
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    • v.17 no.2 s.75
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    • pp.195-206
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    • 2005
  • Experimental research was performed on the 6m-6m two-span, continuous composite beams. Background research for the crack width control of continuous composite bridges in the Eurocode-4 is reviewed and equationsfor the calculation of crack width considering tension stiffening are presented. The behavior of the continuous composite beams was investigated using the initial and stabilized cracking process of the concrete slab in tension. Test results showed that the current requirement of minimum reinforcement for ductility in Korea Highway Bridge Design Codes could be reduced. The flexural stiffness of cracked continuous composite beams can be evaluated by the uncracked section analysis until the stabilized cracking stage. An empirical equation for the relationship between the stress of tensile reinforcements and crack width was obtained from the test results.

Influences of Post Weld Heat Treatment on Fatigue Crack Growth Behavior of Transverse TIG Welded Al6013-T4 Aluminum Alloy Joint (횡방향 TIG 용접된 Al6013-T4알루미늄 합금 용접부의 피로균열전파거동에 미치는 PWHT의 영향)

  • Haryadi, Gunawan Dwi;Kim, Seon Jin
    • Journal of Power System Engineering
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    • v.16 no.4
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    • pp.66-73
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    • 2012
  • 본 연구는 횡방향 TIG 용접된 Al6013-T4 알루미늄 합금 용접부의 피로균열전파거동에 미치는 용접후열처리(PWHT)의 영향을 조사하는 것이 주목적이다. 기초적으로 인장시험, 경도 및 미세조직이 조사되었으며, 피로균열전파거동을 고찰하기 위한 피로 시험은 모두 중앙균열인장(CCT) 시험편에 대하여 수행되었다. T82열처리에 있어서 시효시간은 피로균열전파율, 인장강도 및 경도에 대단히 민감함을 나타내었으며, 모재와 열영향부재의 경우가 용접재보다 기계적 성질이 우수하였다. 횡방향 TIG 용접한 Al6013-T4 시험재의 용접후열처리 조건에 따라서 피로균열전파 저항에는 차이가 나타났으며, 본 실험의 조건하에서 24시간 인공시효 PWHT-82 시험편이 피로균열전파 저항이 가장 우수한 결과를 나타내었다.

Evaluation of Tensile Behaviors of Beam Splice with High Strength Bolts According to Steel Grades (강종에 따른 고력볼트 보 이음부 인장거동 평가)

  • Kim, Hee-Dong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.129-137
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    • 2020
  • In designing a high strength bolted beam splice using steel for building structures, it is necessary to present the appropriate steel grade selection criteria for how to determine the cover plate steel grade. This study examined the difference in tensile behavior according to the steel grades through static tensile tests simulating the beam member high strength bolt joints flange. For this purpose, the specimens were designed and fabricated with the main variables, such as the thickness, steel grade and the strength of flange and cover plate, which are expected to affect the splice strength and behavior. The tensile test results for a total of 48 specimens showed that the tensile-load capacity exceeded the design tensile strength applied with a nominal strength of steel in all specimens. When the design strength of the cover plate exceeded 1.25 times that of the flange plate, the flange plate governed the behavior of splice. The change in maximum tensile load due to the change in flange steel grade is not very large, but there is a difference in deformation. The test results confirmed that the steel grade and thickness of the cover plate were the main factors affecting the beam splice behavior.