탄소섬유보강판의 홈삽입에 따른 철근콘크리트 보의 보강효과

한상훈,최만용,조홍동,박중열,황선일 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.1

This paper presents a feasibility study of an alternative strengthening method by slot-bonded CFRP plates for reinforced concrete beam. A total 14 reinforced concrete beam were constructed, tested and the response of the beams in terms of deflection, strains, failure load and failure mode were examined. Each specimen was initially loaded for 75% of ultimate load, cracked specimen were strengthened with CFRP plate and then tested until complete failure. Test variables included the strengthening method, steel ratio and strengthening length, and the effects according to each test variables are analysed. The experimental results show that proposed methods can increase the flexural strength and stiffness of the beam significantly. Also, the failure of the specimens strengthened by the proposed method are more ductile than externally bonded specimen.

경남지역 벼 친환경재배시 고품질 유색미 생산을 위한 적정 품종

김상열,한상익,오성환,이종희,권영업 忠北大學校 農業科學硏究所 2015 農業科學硏究 Vol.31 No.2

CFRP와 콘크리트 계면에서의 부착특성

한상훈,조홍동,박중열,황선일,김형진 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.2

Externally bonding technique of CFRP(Carbon Fiber Reinforced Polymer Plate) is widely used in strengthening of concrete structures, and the improving effect of flexural strength and stiffness has been proven by early researchers. But, strengthened concrete structures present brittle failure mode accompanied with debonding of CFRP. That is, it means that the behavior of concrete structures strengthened with CFRP is mainly dependent on mechanical characteristics of CFRP and concrete interface. Therefore, double-lap shear test was performed to examine the bond characteristics on interface. The experimental variables are included with the strength of concrete, bond length and width. Test results showed that effective bond length of CFRP is approximately 30cm and maximum interfacial shear stress at specimen failure is 47 kgf/㎠.

철근콘크리트 보에 대한 CFRP의 정착길이

한상훈,최만용,조홍동,박중열,황선일 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.1

A failure mode in the beam strengthened with a high modulus plate appears as a interface debonding failure or ripping-off failure. This failure mode means that plate is separated from adhesive or concrete before displaying its own ability. Therefore, as a method for controlling a premature failure, it is need to use a general anchorage implement. We conducted bending tests for reinforced concrete beams strengthened with CFRP. The experimental variables were a concrete strength, reinforcement ratio, cover thickness of concrete and length ratio of CFRP for a pure span. A failure load, failure mode, load-deflection curve and strain response at different distances from a cut-off of CFRP and strain distribution curve were measured to determine the bond development length. Also, the bond development length was compared with Nguyen’s model and British Standard specification.

유전알고리즘을 이용한 철근콘크리트 보의 최적설계

한상훈,조홍동,박중열,황선일 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.2

This paper describes the application of genetic algorithm for the optimum design of reinforced concrete beam. The cost of reinforced concrete beam as an objective function which includes the costs of concrete, formwork, tensile steel reinforcement and shear reinforcement is minimized. The flexural and shear strength, deflection, upper-lower bounds on steel reinforcement and beam width-depth ratio are considered as the constraints. For the check of the serviceability, deflection is calculated under the service loading by the effective moment of inertia instead of the gross moment of inertia. Optimum results obtained from GA are compared to verify the validity of GA with other literature. Then, GA is applied to 3 span RC beam based on standard specifications.

근골격계 질환 예방을 위한 재생타이어 트레드 버핑머신 개발

김재열,한재호,이연신,김항우,오성민 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

As a part of environmental pollution prevention and resources recycling, the regeneration of waste tire has been largely contributed to national industry. But, the worker has been evaded this regeneration process by reason of the best mischievous process condition among 3D industries.So, the first, the process condition of regeneratingwaste tire was analyzed. The second, the equipment or system was developed for the improvement of working strength and environment. The last, researchers intend to solve these problems

평판 위에 세워진 두 개의 원통 전방에서 나타나는 2차원 표면전단응력분포 측정에 관한 연구

이한상,이열 한국항공대학교 2000 論文集 Vol.38 No.-

본 연구에서는 평판 위에 수직으로 놓여진 두 개의 원통 전방에서 나타나는 2차원 표면전단응력 분포가 측정하는 새로운 기법이 시도되었다. FISF 측정법이라 일컫는 이 측정법은 모델표면 위에 위치한 오일막의 두께가 유동에 의하여 시간에 따라 얇아지는 정도를 광학장치를 통하여 측정하고, 이를 이용하여 표면전단응력 분포를 얻어내는 방법이다. 촬영된 간섭영상에서 오일막의 두께를 구하기 위하여 선형연결법이 응용되었고, 유선의 방향을 결정하기 위하여 잉크점유막법이 사용되었다. 얻어진 두 결과를 오일막 방정식에 대입하여, 최종적인 원통 전방에서의 2차원 표면전단응력 분포가 측정되었다. 측정 결과 원통 전반부에서 표면전단응력은 유동내 attachment line을 따라 점점 감소하며 saddle point 부근에서 0에 근접하고, 원통의 중심축을 지나면서 응력이 증가함을 알 수 있었다. An experimental study to measure two dimensional skin friction distribution ahead of two circular cylinders mounted on a flat plate is described. The instrument termed, the Fringe Image Skin Friction (FISF) meter, is designed to measure skin friction over a certain region of a thin oil-film placed on the test model surface subject to aerodynamic shear. During tests, a CCD camera captures images of fringe pattern produced over the oil film surface, and the linear connection method is applied to determine the oil-film height distribution from the fringe patterns, and the streamline patterns are also determined by means of ink-dot-liquid-film technique. The distribution of oil-film height and streamline patterns can be combined and applied to the thin-oil-equation, and finally the skin friction distribution for a certain area ahead of the two circular cylinders can be obtained. The experimentally obtained result shows that the skin friction decreases along the attachment line and increases to spanwise direction to the symmetric line of the two cylinders.

근골격계 질환 예방을 위한 재생타이어 트레드 버핑작업 개선에 관한 연구

김재열,한재호,이연신,김항우,오성민,송경석 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

As a part of environmental pollution prevention and resources recycling, the regeneration of waste tire has been largely contributed to national industry. But, the worker has been evaded this regeneration process by reason of the best mischievous process condition among 3D industries.So, the first, the process condition of regeneratingwaste tire was analyzed. The second, the equipment or system was developed for the improvement of working strength and environment. The last, researchers intend to solve these problems

傾斜度및 傾斜長이 土壤侵蝕에 미치는 影響에 關한 硏究

朴成宇,劉漢烈 서울大學校 農科大學 1977 서울대농학연구지 Vol.2 No.1

When it comes to reclaiming slopy upland, there should be prepared any facilities and agronomical management systems appropriate enough to protect soil erosion phenomena that are accelarated by the reclamation. The controlling factors for soil erosion are considered as agronnomical management and engineering construction. All the phenomena of soil erosion chiefly consisting of soil detachment, transportation, and sedimentation by raindrop and surface runoff, etc. are varied with so indescribably compricating parameters that they are supposedly natural and consequently uncontrolled events for a long time. Through worldwise enormous experiments for nearly a century, they are under mathematical description. The results are so-called Universal Soil Loss Equation. We have not evaluated the feasibility of the Equation. With our facing impending problems concened with the related undergoing project throughout the Republic, however, the Equation is greatly wanted to be modfied for suitable application through evaluation of each parameter. This study is primarily conducted for the purpose: especially concerned with modification of slop-length factor(??) in the Equation. There being difference between the tested plots and the standard plot described in the Equation, the results would not be fit enough to estimate the direct effects of slope-length parameter on soil loss. Some descriptive results are delivered here between variation of slope-length and corresponding soil loss. The observed soil erosion quantity is about three times more than the calculated value using the established Taneta's ??-values. Such the results imply Taneta's ??-valuefuction may have some restriction applying for the ?? value of the Equation in the Republic.

세탁기용 자동변속기(Auto-Transmission)의 이상음 검사용 자동화 프로그램 개발

김재열,김양중,한재호,마상동,김창현 朝鮮大學校 機械技術硏究所 2000 機械技術硏究 Vol.3 No.1

This study includes automatic program for noise inspection of auto-transmission for washing machine one of modern home necessary. We effort to find and certificate sound noise source by sound power and sound intensity, and apply to frequency analysis in vibration related sound noise. Still more we have been studying to data acquisition and programming for MS VisualBasic version 5.0. System component is below. 1) Pentium PC for data acquisition. 2) DSO for noise acquisition. 3) S/W for comparison and decision. 4) I/F Board for data communication. Wave form data through the DSO are converting to ASCII code data. The ASCII code through binary converting S/W are to be decision fitness or the badness comparison S/W. Finally, we will making noise monitoring system and automatic program for inspection system