• Journal of the Korea Concrete Institute
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• v.20 no.2
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• pp.221-229
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• 2008

An improved unbonded-type column strengthening procedure using wire rope and T-shaped steel plate units was proposed. Eight strengthened columns and an unstrengthened control column were tested under concentric axial load. The main variables considered were the volume ratio of wire rope and the flange width and configuration of T-shaped steel plates. Axial load capacity and ductility ratio of columns tested were compared with predictions obtained from the equation specified in ACI 318-05 and those of conventionally tied columns tested by Chung et al., respectively. In addition, a mathematical model was proposed to evaluate the complete stress-strain relationship of concrete confined by the wire rope and T-plate units. Test results showed that the axial load capacity and ductility of columns increased with the increase of the volume ratio of wire rope and the flange width of T-plates. In particular, at the same lateral reinforcement index, a much higher ductility ratio was observed in the strengthened columns having the volume ratio of wire rope above 0.0039 than in the tied columns. A mathematical model for the stress-strain relationship of confined concrete using the proposed strengthening procedure is developed. The predicted stress-strain curves were in good agreement with test results.

• Journal of Korean Society of Steel Construction
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• v.16 no.4 s.71
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• pp.463-470
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• 2004

In this study, the bearing pressure distribution and design method of rectangular steel tubular column base plates under concentric loading were investigated. In general, the size and thickness of the baseplate are determined with the assumption that the bearing pressure of the column baseplate is uniformly distributed. When the column is loaded lightly, however, the size of the baseplate becomes smaller, the thickness becomes thinner and the bearing pressure of the baseplate is not distributed evenly. In this study, the distribution of the bearing pressure was investigated using the experimental and analytical methods. Four test specimens of the rectangular steel column baseplate were fabricated and tested. The analysis of the specimens was done using the finite element analysis program ANSYS. The result was that it was appropriate to use the effective width method to design the lightly loaded column baseplate, because the bearing pressure was not distributed evenly and was only concentrated under the column section.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.35-47
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• 2003

In the conventional axial load transfer analysis for composite piles (i.e., steel pipe pile filled with concrete), it was assumed that the concrete's strain is same as the measured steel's strain and the elastic modulus of the steel and the concrete calculated by formular as prescribed by specification is used in calculation of pile axial load. But, the pile axial load calculated by conventional method had some difference with the actual pile load. So, the behavior of a composite pile could not be analyzed exactly. Thus, the necessity to measure the strain for each pile components was proposed. In this study, the verification test for DRS (Deformable Rod Sensor) developed to measure the strain of each pile component (i.e., the steel and the concrete) was performed. In the calculation of pile axial load using the DRS, elastic modulus of concrete could be determined by the uniaxial compression test for the concrete cylinder samples made in the test site and an average tangential modulus in the stress range of (0.2∼0.6)f$_ck$ was taken.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.195.2-195.2
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• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.99-100
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• 2010

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.249.1-249
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.249.2-249
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• 1999

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.267-274
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• 2011

The effect of internal ring stiffeners is numerically evaluated for reinforcement of tubular K-joints. Finite element analyses are performed to compute stress of un-stiffened and ring-stiffened K-joints subjected to axial loading. The influence of loading condition and geometrical parameters of ring stiffener on joint behavior is assessed to determine the installation effect of single and double ring stiffeners. The arrangement effect of ring stiffener are evaluated using quantitative analysis compared single ring with double ring stiffeners. Based on the numerical results, practical size of ring stiffener is proposed for design of tubular K-joints.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.10
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• pp.35-41
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• 2005

The problem of an orthotropic composite material with a central crack inclined with respect to the principal axes of material symmetry is studied. The material is subjected to uniform biaxial loading along its outer boundaries. The normal stress ratio theory is applied to predict initial crack extension behavior in cracked composite materials. The dependence of the crack extension angle with respect to the biaxial loading and the principal axes of material symmetry is discussed. Our analysis shows significant effects of horizontal loading, crack angle and fiber angle on the crack extension.

• 전기의세계
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• v.46 no.12
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• pp.8-10
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• 1997

본 학회는 1947년 7월 9일 설립되어 금년으로 뜻깊은 창립 50주년을 맞이하였다. 학회에서는 1997년 7월 9일 창립 50주년 기념일을 맞아 창립 50주년 기념 각종 사업들을 진행하고자 지난 2월 이사회에서 50주년 기념사업 조직위원회를 구성하고 산하에 8개 분과위원회를 두었는데, 그중 50주년 기념행사중 제일 빅 이벤트인 창립 50주년 기념식과 축하연을 담당 진행할 목적으로 기획담당이사를 위원장으로 하여 기획분과위원회가 설치되었다. 기획분과위원회 위원으로는 전기학회 소속 교수중 업무추진력이 있는 중견교수로 구성되었다. 선임된 교수들은 준비하는 행사가 50년에 한번밖에 없다는 생각에 소명의식과 함께 가벼운 흥분을 느끼며 이와 같은 규모와 비중이 있는 행사개최에 대해 처음에는 걱정들이 앞섰으나, 선임된 위원들은 유사한 종류의 행사를 진행하고 준비한 경험이 있는 교수가 많아 행사준비가 원만히 진행될 수 있었다. 창립 50주년 기념식 행사는 아무런 차질없이 잘 진행된 것을 자랑스럽게 여기며 기념식 및 축하연 행사 내용 소개와 준비과정등 기록들을 남김으로서 향후 75주년, 100주년 기념사업을 준비하실 후학 여러분에게는 도움을 주고, 현 회원에게는 진행보고를 하고자 이 글을 남긴다.