• Title/Summary/Keyword: structural member

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Tests on Cementless Alkali-Activated Slag Concrete Using Lightweight Aggregates

  • Yang, Keun-Hyeok;Mun, Ju-Hyun;Lee, Kang-Seok;Song, Jin-Kyu
    • International Journal of Concrete Structures and Materials
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    • v.5 no.2
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    • pp.125-131
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    • 2011
  • Five all-lightweight alkali-activated (AA) slag concrete mixes were tested according to the variation of water content to examine the significance and limitation on the development of cementless structural concrete using lightweight aggregates. The compressive strength development rate and shrinkage strain measured from the concrete specimens were compared with empirical models proposed by ACI 209 and EC 2 for portland cement normal weight concrete. Splitting tensile strength, and moduli of elasticity and rupture were recorded and compared with design equations specified in ACI 318-08 or EC 2, and a database compiled from the present study for ordinary portland cement (OPC) lightweight concrete, wherever possible. Test results showed that the slump loss of lightweight AA slag concrete decreased with the increase of water content. In addition, the compressive strength development and different mechanical properties of lightweight AA slag concrete were comparable with those of OPC lightweight concrete and conservative comparing with predictions obtained from code provisions. Therefore, it can be proposed that the lightweight AA slag concrete is practically applicable as an environmental-friendly structural concrete.

Analysis of Compressive Fracture Behavior of Filled FRP Composite Box Module (충전형 FRP 합성박스 모듈의 압축파괴 거동 분석)

  • Kim, Ho-Sun;Jang, Hwa-Sup;Lee, Ho-Hyun;Yun, Kuk-Hyun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.1
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    • pp.1-8
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    • 2012
  • This study is a basic experimental research to apply FRP (Fiber Reinforced Polymer) box members to slabs and girders among various architectural structures, which receive bending stress. We prepared prefabricated FRP member and connected it to an FRP box member as a large cross section before we conducted an experiment in diverse conditions to analyze characteristics of compressive fracture behavior. In this study, we carried out a compressive fracture behavior test according to fillers on the upper part of the FRP box member, loading methods, and connective types and thereby performed a finite element analysis. The comparison of analysis results with test results revealed that rigidity was found to be slightly low, while stress was concentrated on the fracture point of the sample.

Experimental study on partially-reinforced steel RHS compression members

  • Pinarbasi, Seval
    • Structural Engineering and Mechanics
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    • v.63 no.3
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    • pp.385-400
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    • 2017
  • This paper presents an experimental study on the behavior of axially-loaded steel RHS (rectangular hollow section) compression members that are partially reinforced along their lengths with welded steel plates. 28 slender column tests were carried out to investigate the effects of the slenderness ratio of the unreinforced member and the ratio of the reinforced length of the member to its entire length. In addition to the slender column tests, 14 stub-column tests were conducted to determine the basic mechanical properties of the test specimens under uniform compression. Test results show that both the compressive strength and stiffness of an RHS member can be increased significantly compared to its unreinforced counterpart even when only the central quarter of the member is reinforced. Based on the limited test data, it can be concluded that partial reinforcement is, in general, more effective in members with larger slenderness ratios. A simple design expression is also proposed to predict the compressive strength of RHS columns partially reinforced along their length with welded steel plates by modifying the provisions of AISC 360-10 to account for the partial reinforcement.

Effects of geometrical initial imperfection in proportioning member sections of single layer reticulated dome (단층 래티스 돔의 단면산정에 있어서의 형상초기불완전의 영향)

  • Kim, Jong-Min;HwangBo, Seok;Han, Sang-Eul;Kwun, Teak-Jin
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.83-88
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    • 2004
  • First author proposed a proportioning method for member sections of a single layer reticulated dome subjected to uniform and non-uniform load without any geometrical initial imperfection, and discussed the validity and effectiveness of the method which was based on linear buckling stress and a knock down factor. However, buckling of a single layer reticulated dome is strongly affected by initial imperfection. It is well known that geometrical initial imperfections reduce the nonlinear buckling capacity of a single layer raticulated dome. Thus, structural engineers may be recommended to reflect the effects of geometrical initial imperfections in proportioning member sections. In this paper, firstly, the presented proportioning method by first author is applied to dome without consideration of any imperfections and the thickness and diameter of each member are determined. Secondly, the load bearing capacities of the proportioned domes are checked with the imperfection, by the inelastic buckling analysis.

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Performance Comparison of Butterfly Joints between Manual Member and Pre-cut Member (수가공 및 기계가공 된 나비장 접합부의 성능 비교)

  • Kim, Gwang-Chul;Kim, Jun-Ho
    • Journal of the Korea Furniture Society
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    • v.27 no.3
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    • pp.165-174
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    • 2016
  • To modularize the joints of Hanok, the bending strengths of butterfly joints between pre-cut and manual member were compared. Structural size joints were manufactured and the length, width and thickness of each tenon were produced with different sizes. The ultimate load of pre-cut members was 2 times higher than that of manual members. Degree of anchorage for the joints on pre-cut member was also superior to that of manual member. By the F-test results, a great influence between ultimate load and sizes of tenon was found. In result of multiple regression analysis, the length and thickness of tenon were showed proportion relationships with the ultimate load, but the width of tenon was showed inverse proportion with the ultimate load. The results of this study can be used to identify the relationships among the major influence factors. Futhermore, it might be used as basic data for modularization the joints of Hanok.

A mathematical model for the along-wind coefficient of tower crane based on the member load

  • Wei Chen;Xianrong Qin;Zhigang Yang
    • Wind and Structures
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    • v.37 no.5
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    • pp.347-359
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    • 2023
  • The along-wind coefficient is the key parameter for wind load calculations in tower crane structure design. It is often calculated using overall parameter characteristics, which may lead to inaccurate results. In this study, six types of tower masts and four types of tower jibs with different overall structural characteristics and member characteristics are established. Through wind tunnel force tests and CFD numerical simulation, the along-wind coefficient of the overall structure and each member are obtained. Based on the characteristics of the slenderness ratio and spacing ratio of the members, a mathematical model for calculating the along-wind coefficient of the tower crane structure is proposed. The calculated results are in accordance with the wind tunnel test results. The maximum relative error is -6.25%, and the minimum relative error is 0.68%. To ensure accuracy, it is necessary to calculate the along-wind coefficient of the tower crane structure based on the load of each structure member rather than using overall parameter characteristics.

EU Enlargement: Regional Policy and Regional Disparity (EU 확대에 따른 지역정책 및 지역격차 변화)

  • Moon, Nam-Cheol
    • Journal of the Economic Geographical Society of Korea
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    • v.13 no.3
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    • pp.442-456
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    • 2010
  • The european union used the regional policy for a compensation for a economic loss of the underdeveloped member countries and for a conciliation of the new member countries with a geographical enlargement. As a result, the objet of regional policy and the support eligible regions of structural funds increased. According to the central and eastern europe countries entry into the european union, the european union modified the regional policy: the integration of the dispersed objects of regional policy into the 3 objects, the reduction of the support eligible region of structural funds and the promotion of the interregional cohesion policy. The development disparities of the between the member countries converged. But the inter-local development disparities of a intra-member country dispersed. This tendency means that the regional policy of the european union contributed for the reduction of development disparities between the member countries but produced no effect on the diminution of the inter-local disparities of a intra-member country because of the regional differentiation of locational conditions.

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Earthquake Resistance Capacity of a Typical Bridge by Connection Design (연결부분 설계에 의한 일반교량의 내진성능)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.5
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    • pp.543-550
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    • 2010
  • Earthquake resistant design should provide a description of the structural failure mechanism under earthquakes as well as satisfy the requirement of other designs, e.g. design strengths of each structural member should be equal or greater than the required strengths. The reason of such a requirement is the randomness of seimic loads different from other loads. In this study, a typical bridge is selected as an analysis bridge and the procedure is given to get the ductile failure mechanism through connection design. It is shown with the procedure that the earthquake resistant capacity can be ensured within structural member's strengths required by other designs, without cost raise by strength increase of structural members or by use of shock absorbing device e.g. shock transfer unit.