• 한국농공학회지
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• 제43권6호
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• pp.113-119
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• 2001

Experiments on the yield strength of pipe connectors made of metal wire, joint pins, pole pipes, multi span insertion joints, and T-clamp joints used in pipe houses were conducted. The strength of connections of a pipe connector made of metal wire was adequate but it had a big difference according to loading direction. Therefore as it is installed, its direction should be taken into consideration. The collapse load of pipes connected with a joint pin was lower than that of single pipes. In the part of frame member at which the great bending moment occurs, the use of joint pin should be avoided. Also experimental results showed that pole pipes for use in a part of frame buried under the ground were safe, and the strength of multi span insertion joints should be increased. The resistant moment of T-clamp was about 13.7% of a single pipe. In case that the external forces acting on left and right rafter are different. a unsymmetrical rotational force is produced at the multi span joint. If it is expected that the actual bending moment on the multi span joint is larger than resistant moment of T-clamp, a reinforcement to safely resist the rotational force is required.

• 한국안전학회지
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• 제17권2호
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• pp.16-21
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• 2002

At present the Polyethylene piping, on supporting LNG is widely used because of it's disposition which are anti-corrosion flexible and so on. However, it has a few kinds of risk which are the possibility of piping leak, the character of easily corroded and so on. For giving solution, this study is intended to experiment the intension of the PE pipe after melted and when it is melting, the condition which are temperature and pressure is changed. the melting condition in temperature and pressure is adapted identically. After melting, it's joint is tested as intension. The result is that the effect of temperature in intension is more effective than pressure. In $210^{\circ}C$, $20kg/cm^{2}$ condition, the melting intension has the highest. Compare to the Butt melting joint and the Saddle melting joint, the former was $214kg/cm^{2}$ and the latter was $50kg/cm^{2}(bead\;2{\sim}3mm)$ and $73kg/cm^{2}(bead\;5{\sim}7mm)$. It means that the Butt melting method has more intensive than saddle. Consequently, the result shows that the liability and safety when pipe melting method is used will improve in pipe installation.

• Journal of Welding and Joining
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• 제21권6호
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• pp.40-45
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• 2003

Steel members have advantages of resisting torsion and axial compression. In design, residual stresses at the welded joint of T-shape steel pipes are one of the most important points to be considered. In this paper, characteristics of residual stresses of welded joints are clarified by carrying out 3D non-steady heat conduction analysis and 3D thermal elastic-plastic FE-analysis. According to the results, the production mechanism of residual stresses at the welded joint of T-shape steel pipe is clarified. In this paper, circumferential stresses depended on thermal histories but axial and radial stresses were more dependent on geometrical shape than thermal histories. Residual stresses in the axial direction on the lower part of pipe member were tensile, controlled by geometrical shape. However, in case of middle part, residual stresses in all the directions were controlled by thermal histories.

• Journal of Welding and Joining
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• 제4권2호
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• pp.30-39
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• 1986

In manufacturing of pipe walls for boiler units, distortion can result in pipe-web-pipe joints from the nonuniform expansion and contraction of the weld metal and the adjacent base metal during heating and cooling cycle of the welding process. In this study, the stresses and strains during longitudinal welding of the plate-to-pipe joint were investigated. Using the method of successive elastic solution, longitudinal stresses and strains during and after welding were calculated from the information of temperature distributions obtained by Rosenthal's equations. In order to confirm the validity of the numerical results, the temperature and residual stress distributions were measured and compared with the calculated results. In spite of some assumptions, the one-dimensional analytical results of residual stresses were in fairly good agreement with the experimental ones. The residual stresses due to welding of plate-to-pipe joints are tensile near the weld line and compressive in the base metal as in the welding of plates. the amount and distribution of residual stresses were deeply dependent on the heat input ratio of the plate and pipe.

• 한국가스학회지
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• 제15권4호
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• pp.39-43
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• 2011

본 연구에서는 가스배관용 플렉시블 조인트의 응력과 변형거동 특성을 유한요소법으로 해석하였다. 이러한 특성결과는 나선 주름관이나 직각 주름관 및 평면관으로 구성된 플렉시블 조인트의 강도안전성을 고찰할 수 있다. FEM 계산결과에 의하면, 최적의 나선 주름관은 $4.7^{\circ}$의 경사각도와 1.5mm의 주름높이를 갖는 주름관 모델인것으로 나타났다. 또한, $90^{\circ}$의 주름을 갖는 직각 주름관 모델이 경사각도를 갖는 나선 주름관보다는 강도안전성이 더 우수한 것으로 나타났다. 따라서, 주름관의 강도안전성을 높이기 위해서는 주름관의 피치와 곡률반경을 줄이는 것이 바람직함을 알 수 있다.

• 한국산학기술학회논문지
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• 제10권9호
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• pp.2202-2209
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• 2009

모관과 지관의 다양한 접합형상에 대하여 접합궤적을 수학적으로 유도하였다. 이 접합궤적에 용접부의 루트갭 및 절단폭 등을 보정하여 실제적으로 절단궤적을 결정하여 NC 코드를 생성하고 그 경로를 확인하기 위하여 ghost 기능을 구현하였다. 척회전인 C축의 8개 구간별로 A, B축의 Tilting을 사용하여 개선 기능을 구현하였으며, 이는 절단궤적을 따라서 절단하면서 동시에 개선이 가능하도록 6축 CNC 파이프 코스터 전용 CAM 프로그램을 개발하였다.

• 한국산학기술학회논문지
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• 제10권11호
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• pp.3066-3073
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• 2009

3축 파이프 형상절단기에서 다양한 접합형상에 대하여 모관과 지관의 접합궤적을 수학적으로 유도하였다. 그 접합궤적에 절단폭 등의 공구 보정하여 실제로 가공할 절단궤적을 결정하여 이 공구궤적에 해당하는 CL-data를 생성하고, 또한 공구 궤적을 확인하기 위하여 ghost 기능을 구현하였다. 생성된 CL data를 PLC의 위치결정제어 모듈에 로딩하여 동시 3축($\alpha$, X, $\beta$축)의 이송을 제어하여 경로를 따라서 형상절단과 동시에 개선을 할 수 있도록 동시3축 파이프 형상절단 시스템을 개발하였다.

• 한국공간구조학회논문집
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• 제15권1호
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• pp.103-110
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• 2015

To overcome disadvantages of usual spread foundation in large space structure, some prototypes of a joint of the PHC pile to steel pipe column that directly connects a column to a PHC pile are analytically studied. With the consideration of strength requirement and stress concentration of joint of the PHC pile to column, we suggest the most appropriate one.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.271-274
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• 2001

Experiments on the yield strength of pipe connectors made of metal wire, joint pins, pole pipes, multi span insertion joints, and T-clamp joints used in pipe houses were conducted. The strength of connections of a pipe connector made of metal wire was adequate but it had a big difference according to loading direction. The collapse load of pipes connected with a joint pin was lower than that of single pipes. Also experimental results showed that pole pipes for use in a part of frame buried under the ground were safe, and the strength of multi span insertion joints should be increased. The resistant moment of T-clamp was about 13.7% of a single pipe.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.502-505
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• 2008

Due to continuous difficulty of human power supply, it is necessary to develop an equipment which is good to saving cost and time at a construction site. A quick pipe coupling method is the kind of mechanical joint system using split-sleeve and sealing-pad at pipe groove without welding. In hence, it provides restrained pipe joint which is simple, safe, and dependable without environmental pollutions. It is more useful scheme than the other ones. The purpose of this study is to find out the main design factors and the optimum shape of split-sleeve. The stress analyses were carried out under various shapes of pipe groove configuration, materials and internal pressures with a commercial software, ANSYS workbench which uses FEM(finite element method). Results are graphically depicted with various parameters.