• Title/Summary/Keyword: Compression load

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A Study on the Performance Certification of 5,200ton Compression Load Tester (5,200톤 재하 시험장비의 성능 검증에 관한 연구)

  • Kim, Kwang-Young;Choi, Young-Ho;Ham, Young-Bog;Choi, Byung-Oh;Lee, Dong-Ha
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.149-154
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    • 2001
  • In case of high capacity load force as millions of tons, it is difficult to measure the force with load cell. But we can measure and calculate the force with applied pressure and ram area of hydraulic jack. The 5,200 ton compression load tester is composed of thirteen hydraulic jack with 400 ton capacity. This paper explains the method of measuring the vertical compression load and provides characteristics of unit jack, and displacement of upper structure under maximum load condition.

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CFRP strengthening of steel columns subjected to eccentric compression loading

  • Keykha, Amir Hamzeh
    • Steel and Composite Structures
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    • v.23 no.1
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    • pp.87-94
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    • 2017
  • Steel structures often require strengthening due to the increasing life loads, or repair caused by corrosion or fatigue cracking. Carbon Fiber Reinforced Polymers (CFRP) is one of the materials used to strengthen steel structures. Most studies on strengthening steel structures have been carried out on steel beams and steel columns under centric compression load. No independent article, to the author's knowledge, has studied the effect of CFRP strengthening on steel columns under eccentric compression load, and it seems that there is a lack of understanding on behavior of CFRP strengthening on steel columns under eccentric compression load. However, this study explored the use of adhesively bonded CFRP flexible sheets on retrofitting square hollow section (SHS) steel columns under the eccentric compression load, using numerical investigations. Finite Element Method (FEM) was employed for modeling. To determine ultimate load of SHS steel columns, eight specimens with two types of section (Type A and B), strengthened using CFRP sheets, were analyzed under different coverage lengths, the number of layers, and the location of CFRP composites. Two specimens were analyzed without strengthening (control) to determine the increasing rate of the ultimate load in strengthened steel columns. ANSYS was used to analyze the SHS steel columns. The results showed that the CFRP composite had no similar effect on the slender and stocky SHS steel columns. The results also showed that the coverage length, the number of layers, and the location of CFRP composites were effective in increasing the ultimate load of the SHS steel columns.

Effects of Temperature and Curing Systems on Compression Set of NR Compounds at Constant Load (천연고무의 일정 하중 영구압축률에 대한 온도와 가교 시스템의 영향)

  • Jin, Hyun-Ho;Hong, Chang-Kook;Cho, Dong-Lyun;Kaang, Shin-Young
    • Elastomers and Composites
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    • v.44 no.1
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    • pp.41-46
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    • 2009
  • The effects of temperature and curing systems on the compression set of natural rubber (NR) at constant load were investigated. NR was compounded with various amounts of sulfur and DCP in order to obtain various crosslink densities and curing systems. Compression sets at constant load were compared with those at constant strain. Compression set at constant load was more affected by changes in crosslink density than compression set at constant strain, due to the differences of exerted strain energy density. Compression set of sulfur cured NR under constant load was increased with increasing load and temperature, but the compression set of DCP cured NR was not changed by increasing load and temperature.

An Experimental Study on Heat Transfer and Flow in Compression Molding of SMC (SMC 압축성형의 열 및 유동에 관한 실험적 연구)

  • 김기택;정진호;임용택
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.9
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    • pp.2386-2395
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    • 1994
  • An experimental study on heat transfer and flow in compression molding of clss-B and A SMC(Sheet Molding Compounds) in a flat plate and a cross-sectional T-shape was carried out. The temperature was measured with thermocouples at two locations in the 4 layered SMC charge and pressure was measured at the center of the top mold during compression molding. Three different mold speeds, 15, 45, 50 mm/min and two different mold temperature, $130^{\circ}C{\;}and{\;}150^{\circ}C$ were used for compression molding experiments. Experiments with different colored SMC layers were used to study flow patterns at various compression stages. In oder to predict the pressure and load in SMC compression molding, slab method was used. The predicted values of pressure and load from the slab analysis were compared well with the measured data.

Load Transfer Mechanism of Hybrid Model of Soil-nailing and Compression Anchor (쏘일네일링과 앵커가 결합된 하이브리드 공법의 하중전이 메커니즘)

  • Seo, Hyung-Joon;Kim, Hyun-Rae;Han, Shin-In;Lee, In-Mo
    • Journal of the Korean Geotechnical Society
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    • v.28 no.1
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    • pp.55-66
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    • 2012
  • The load transfer mechanism of hybrid model of soil-nailing and compression anchor is studied in this paper. The hybrid model is composed of an anchor bar (installed at the tip) with two PC strands and a steel bar. It can make active behavior of skin friction by applying the pre-stress. In this paper, the load transfer mechanisms of soil-nailings, compression anchors, and hybrid models, respectively, are obtained from skin friction theory and load transfer theory. Field pullout tests are performed to identify the load transfer mechanism and experimental results are compared with analytical solution. In case of soil-nailings, the tension load is transferred from face to tip, however, in case of compression anchors, the compression load is transferred from tip to face. The experimental behavior of the hybrid model is similar to that of compression anchor when only pre-stress is applied. If the pullout test is performed by simultaneously pulling out the anchor and the nail, the compression load is dominant at the tip and tension load is dominant at the face. The load transfer mechanism of the hybrid model shows the combined behavior of soil-nailings with compression anchors.

Studies on T-Shaped composite columns consist of multi separate concrete-filled square tubular steel sections under eccentric axial load

  • Rong, Bin;You, Guangchao;Zhang, Ruoyu;Feng, Changxi;Liu, Rui
    • Steel and Composite Structures
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    • v.22 no.2
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    • pp.217-234
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    • 2016
  • In order to investigate mechanical properties and load-bearing capacity of T-shaped Concrete-Filled Square Steel Tubular (TCFST) composite columns under eccentric axial load, three T-shaped composite columns were tested under eccentric compression. Experimental results show that failure mode of the columns under eccentric compression was bending buckling of the whole specimen, and mono column performs flexural buckling. Specimens behaved good ductility and load-bearing capacity. Nonlinear finite element analysis was also employed in this investigation. The failure mode, the load-displacement curve and the ultimate bearing capacity of the finite element analysis are in good agreement with the experimental ones. Based on eccentric compression test and parametric finite element analysis, the calculation formula for the equivalent slenderness ratio was proposed and the bearing capacity of TCFST composite columns under eccentric compression was calculated. Results of theoretical calculation, parametric finite element analysis and eccentric compression experiment accord well with each other, which indicates that the theoretical calculation method of the bearing capacity is advisable.

Studies on the Influence of Sample thickness, Load Increment Ratio and Load Increment Duration on Consolidation Characteristics. (시료의 두께, 하중증가율 밀 재하시간이 압밀특성에 미치는 영향)

  • 류능환;강예묵
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.20 no.3
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    • pp.4750-4770
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    • 1978
  • Under the various variations of the sample thickness, the load increment ratio and the load increment duration, this consolidation test of the clay in the Asan Bay was tried for the comparison with the standard consolidation test. The results gained are as follows; 1. The void ratio variations of the leached-clay samples were increasingly high, according as the sample thickness thinned and the load increment duration and the laod increment ratio increased. 2. The coefficient of consolidation were increased with the increment of the sample thickness, of the load increment ratio and of the load increment duration. Near the pre-consolidation load, the coefficient of secondary consolidation had the maximum value and lessened with the increment of the sample thicknss, and of the load increment duration 3. The value of the pre-consolidation load increased in proportion to the increment of the sample thickness and the decrease of the load increment ratio and the load increment duration. 4. The compression indices increased as the increment of load increased and decreased as the sample thickness increased. 5. The initial compression ratio increased as the sample thickness, the load increment ratio and the load increment duration decreased. The ratio of primary compression to the secondary decreased with the increment of the sample thickness and of the load increment ratio. 6. The time at the completion of psimary consolidation increased with the increment of the sample thickness and of the consolidation load, and with the decrease of the load increment ratio. 7. The compression indicses increaed as the sample thickness lessened and decreased as the load increment ratio increased. The coefficient of consolidation increased according as the sample thickness, the load increment ratio and the load increment duration went up. The settlement at the construction site should be calculated highly in proportion as the sample thickness lessened and the load increment ratio increased. The consolidation ratio is thought to be accelerated if the sample thickness and the load increment ratio becomes higher and the load increment duration longer.

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Study on Compression Tests of Aluminum Foam and Honeycomb Sandwich Composites (알루미늄 폼 및 허니컴 샌드위치 복합재료의 압축실험에 관한 연구)

  • Bang, Seung-Ok;Kim, Key-Sun;Kim, Sei-Hwan;Song, Soo-Gu;Cho, Jae-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.9
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    • pp.3802-3807
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    • 2011
  • In this study, in-plane and out-plane compression tests of aluminum foam and honeycomb sandwich composites were carried out. Through these tests, the relationships of load-displacements were analyzed and the compression characteristics were compared with each other. The specimens were compressed with the speed of 1mm/min by using the universal testing machine. Experimental procedures were taken with photograph by the camera and load cell data were stored into computer. Test results showed that buckling was occurred at the aluminum foam core and honeycomb core according to the increase of load. In the in-plane compression test, the maximum load of aluminum foam specimen was similar with that of honeycomb sandwich. The property of honeycomb was better than that of the foam in consideration of specific gravity. In the out-plane compression test, compression maximum load of aluminum honeycomb sandwich composite was higher than that of aluminum foam sandwich composite.

Damped Vibrations of Axially-Stressed Laminated Beams using Zig-Zag Finite Element (축방향 하중을 받는 점탄성물질이 심어진 적층보의 지그재그요소를 이용한 진동해석)

  • 이덕규
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.1-4
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    • 2001
  • Dynamic analysis of laminated beams with a embedded damping layer under tension or compression axial load is investigated. Improved Layer-Wise Zig-Zag Beam Theory and Interdependent Kinematic Relation using the governing equations of motion are incorporated to model the laminated beams with a damping layer and a corresponding beam zig-zag finite element is developed. Flexural frequencies and modal loss actors under tension or compression axial load are calculated based on Complex Eigenvalue Method. The effect of the axial tension and compression load on the frequencies and loss factors is discussed.

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Vibration Analysis of Axially-Stressed Composite Beam with Viscoelastic Layer (점탄성층을 갖는 복합재보의 축하중 작용시 진동해석)

  • 이덕규
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.33-38
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    • 2002
  • Dynamic analysis of laminated beams with a embedded damping layer under tension or compression axial load is investigated. Layer-Wise Zig-Zag Beam Theory and Interdependent Kinematic Relation using the governing equations of motion are incorporated to model the laminated beams with a damping layer and a corresponding beam zig-zag finite element is developed. Flexural frequencies and modal loss factors under tension or compression axial load are calculated based on Complex Eigenvalue Method. The effects of the axial tension and compression load on the frequencies and loss factors are discussed.

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