• Title/Summary/Keyword: Column experiments

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Experimental Study on Local Scour around Bridge Piers by Scour Protection Devices (세굴보호장치에 의한 교각주위의 국부세굴 실험)

  • 최기봉;김응용
    • Journal of the Korean Society of Safety
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    • v.15 no.1
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    • pp.126-131
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    • 2000
  • This study based on the laboratory works, analyzes factors affecting local scour in order to understand various characteristics of the local scour surrounding bridge piers. Attached with scour protection device as a method for decreasing local scour, it carries out the laboratory experiments and calculates the scour depth. From the experiments attached with the scour protection devices, it seems possible to reduce the scour depth as the protecting plate, column and sacrificial piles are built in the same height with flume bed at pier or footing upstream interrupted falling-flow. And then it could reduce scour depth. The paper presents the following research results: First, the decreasing degree of scour depth is in order of protecting column, protecting plate, sacrificial piles and non-protecting facilities. However, it shows no meaningful difference between protecting column and protecting plate. Second, when $L_p/b$=0.5~1, the decreasing effect of scour depth reached the maximum of 40 percents.

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Extraction of Chromium (Vl) Son in Waste Water through the Liquid Surfactant Membrane with Open-Type Perforated Reciprocating-Plate Column (개방형 왕복 다공판 추출탑을 이용한 액막법에 의한 폐수중 Cr(Vl)의 추출)

  • 우인성;강현춘;안형환
    • Journal of the Korean Society of Safety
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    • v.8 no.2
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    • pp.44-50
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    • 1993
  • The objective of this study was to investigate the extraction of chromium(Vl) ion in waste water through the liquid surfactant membrane with open-type Perforated Reciprocating-Plate Column. Extraction experiments were conducted to measure the effect of flow characteristics of continuous and dispersed phase and stroke velocity, sodium hydroxide concentraction in internal aqueous phase, sulfuric acid concentraction in outer phase, and residence time distribution and measured extraction velocity. The result of experiments showed that extraction velocity of chromium ion was maximum when stroke velocity was 180 1/min and dispersion phase velocity was 30m11min, continuous phase velocity was 20m1/min. Extraction velocity of chromium ion increased with increasing difference of hydrogen ion concentraction of dispersion and continuous phase and column stage decreased.

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Experimental research on load-bearing capacity of cast steel joints for beam-to-column

  • Han, Qinghua;Liu, Mingjie;Lu, Yan
    • Structural Engineering and Mechanics
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    • v.56 no.1
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    • pp.67-83
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    • 2015
  • The load transfer mechanism and load-bearing capacity of cast steel joints for H-shaped beam to square tube column connection are studied based on the deformation compatibility theory. Then the monotonic tensile experiments are conducted for 12 specimens about the cast steel joints for H-shaped beam to square tube column connection. The findings are that the tensile bearing capacity of the cast steel joints for beam-column connection depends on the ring of cast steel stiffener. The tensile fracture happens at the ring of the cast steel stiffener when the joint fails. The thickness of square tube column has little influence on the bearing capacity of the joint. The square tube column buckles while the joint without concrete filled, but the strength failure happens for the joint with concrete filled column. And the length of welding connection between square tube column and cast steel stiffener has little influence on the load-bearing capacity of the cast steel joint. Finally it is shown that the load-bearing capacity of the joints for H-shaped beam to concrete filled square tube column connection is larger than that of the joints for H-shaped beam to square tube column connection by 10% to 15%.

Effective Punching Shear and Moment Capacity of Flat Plate-Column Connection with Shear Reinforcements for Lateral Loading

  • Song, Jin-Kyu;Kim, Ju-Bum;Song, Ho-Bum;Song, Jeong-Won
    • International Journal of Concrete Structures and Materials
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    • v.6 no.1
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    • pp.19-29
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    • 2012
  • In this study, three isolated interior flat slab-column connections that include three types of shear reinforcement details; stirrup, shear stud and shear band were tested under reversed cyclic lateral loading to observe the capacity of slab-column connections. These reinforced joints are 2/3 scale miniatures designed to have identical punching capacities. These experiments showed that the flexural failure mode appears in most specimens while the maximum unbalanced moment and energy absorbing capacity increases effectively, with the exception of an unreinforced standard specimen. Finally, the results of the experiments, as wel l as those of experiments previously carried out by researchers, are applied to the eccentricity shear stress model presented in ACI 318-08. The failure mode is therefore defined in this study by considering the upper limits for punching shear and unbalanced moment. In addition, an intensity factor is proposed for effective widths of slabs that carry an unbalanced moment delivered by bending.

Geometrical Non-linear Analyses of Tapered Cantilever Column Subjected to Sub-tangential Follower Force (경사 종동력을 받는 변단면 기하 비선형 캔틸레버 기둥의 수치해석)

  • Lee, Byoung-Koo;Oh, Sang-Jin;Lee, Tae-Eun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.1
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    • pp.29-38
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    • 2013
  • This paper deals with geometrical non-linear analyses of the tapered cantilever column subjected to the sub-tangential follower force at the free end. Cross-sections of the column whose flexural rigidities are functionally varied with the axial coordinate. The differential equations governing the elastica of such column are derived on the basis of the large deformation theory. These differential equations have three unknown parameters of the vertical and horizontal deflections and rotation at the free end. These differential equations are numerically solved by the iteration technique for obtaining three unknowns and elastica of the deformed column. For validating theories developed herein, laboratory scaled experiments are conducted.

Injection Molding Experiments for Small Diameter Column (미소 원주의 사출 성형 실험)

  • 제태진;이응숙;김재구
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.85-88
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    • 1995
  • Recently, the micro mold maching techining technology is developed by means of the mechanical and high energy beam process. It is possible to make the micro structure mold with high aspect ratio by the LIGA technology. This mode is used for mass production of plastic parts by the micro injection molding method. In this study, we intend to research on the basic technology of micro injection molding. As the result, we developed the injection molding technology for small column plastic parts which diameter is 500 .mu. m and 200 .mu. m respectively with wbout aspect ratio 20.

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Seismic experiment and analysis of rectangular bottom strengthened steel-concrete composite columns

  • Hui, Cun;Zhu, Yanzhi;Cao, Wanlin;Wang, Yuanqing
    • Steel and Composite Structures
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    • v.20 no.3
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    • pp.599-621
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    • 2016
  • In order to study the working mechanism of rectangular steel-concrete composite columns subjected to compression-bending load and further determine the seismic performance index, a bottom strengthened rectangular steel reinforced concrete (SRC) column with concealed steel plates and a bottom strengthened rectangular concrete filled steel tube (CFST) columns were proposed. Six column models with different configurations were tested under horizontal low cyclic loading. Based on the experiments, the load-bearing capacity, stiffness and degradation process, ductility, hysteretic energy dissipation capacity, and failure characteristics of the models were analyzed. The load-bearing capacity calculation formulas for a normal section and an oblique section of bottom strengthened rectangular steel-concrete composite columns were pesented and a finite element (FE) numerical simulation of the classical specimens was performed. The study shows that the load-bearing capacity, ductility, and seismic energy dissipation capacity of the bottom strengthened rectangular steel-concrete composite columns are significantly improved compared to the conventional rectangular steel-concrete composite columns and the results obtained from the calculation and the FE numerical simulation are in good agreement with those from the experiments. The rectangular steel-concrete composite column with bottom strengthened shows better seismic behavior and higher energy dissipation capacity under suitable constructional requirements and it can be applied to the structure design of high-rise buildings.

Column Removal of Trichloroethylene and Dichloromethane using Low Cost Activated Carbon

  • Radhika, M.;Lee, Young-Seak;Palanivelu, K.
    • Carbon letters
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    • v.11 no.1
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    • pp.13-21
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    • 2010
  • Coconut shell activated carbon (CSAC) was investigated for its ability in the removal of two neutral chlorinated organic compounds, namely trichloroethylene (TCE) and dichloromethane (DCM) from aqueous solution using a packed bed column. The efficiency of the prepared activated carbon was also compared with a commercial activated carbon (CAC). The important design parameters such as flow rate and bed height were studied. In all the cases the lowest flow rate (5 mL/min) and the highest bed height (25 cm) resulted in maximum uptake and per cent removal. The experimental data were analysed using bed depth service time model (BDST) and Thomas model. The regeneration experiments including about five adsorption-desorption cycles were conducted. The suitable elutant selected from batch regeneration experiments (25% isopropyl alcohol) was used to desorb the loaded activated carbon in each cycle.

Development of Drilling Center Column made of Epoxy-granite Material and Experimental Study on it's Structural Characteristics (드릴링 센타용 애폭시-그래나이트재 컬럼의 개발과 구조물 특성 실험)

  • Won, S.T.;Kim, J.H.;Lee, H.W.;Maeng, H.Y.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.1
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    • pp.87-96
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    • 1995
  • A new fungivle material named Epoxy-Granite composite is applied to the column structure of drilling center in order to investigate the advanced dynamic charateristics comparing with a conventional cast iron material. The dimensions of new column structure are adjusted to keep the same stiffness (EI value) and the manufacturing conditions are formulated based on the preceeding research experience about the development of Epoxy-Granite structural material. The two kinds of experiments are set up, one of which is for the measurement of natural mode and frequency using experimental modal analysis, and the other one is for the measurement of vibration amplitude during idling operation of a machine tool. The comparison of maximum accelerance values at each natural frequency of bending mode shows a Epoxy-Granite column have larger modal damping ratios(over 2times) than a cast iron column. The vibration amplitude of Epoxy-Granite column measrued on the bed, motor base, and top of column are also much smaller (up to 12%) than the case of cast iron column. It is therefore confirmed that a Epoxy-Granite material exhibits a good anti- vibrational propderty even if it is used under the actual operational environments of machine tool as a practical structural element.

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An Experimental Study on Column Penetration Joint of RC Column-Steel Beam (기둥관통형 RC 기둥-철골 보 접합부에 관한 실험적 연구)

  • 김승훈;한상환;이리형
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04b
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    • pp.475-480
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    • 1998
  • The composite framed structures, consisting of RC columns and steel beams more popular in korea because of their efficiency and quality. However the force transfer mechanisms between the column and beam may by very complicated since the materials of columns and beams are different. This study develops "the column penetration joint" which the web of steel beam doesn't penetrate and which could improve the strength, deformation, and energy dissipation capacities compared to existing composite joints. It is the concrete-filled square tube joint with the exterior diaphragms and the cruciform stiffening plates. This study evaluated the strength of RC column penetration to steel beam connection by analyzing the results of partial experiments, and reviewed the applicability the strength formula through the comparison of tested results of joint experiment.

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