• Journal of Advanced Marine Engineering and Technology
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• 제27권6호
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• pp.728-735
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• 2003

This paper shows the possibility of performing Lap joint using the friction stir welding with $2mm^t$ aluminum alloy plate and the determination of tool-dimensions for FSW in milling machine. This research also is reported on obtaining the tensile-shear strength, 91.3 (MPa) and the energy absorption, 26.3 (J) for Lap jointed specimen. The optimal tool-dimensions and method for Lap joint using FSW is as follows; each diameter of shoulder and pin is $9\phi(mm) and 3\phi(mm)$, the length of pin is 3.6(mm), Pressing the shoulder of tool into original base metal is not reasonable.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 추계학술대회 논문집(Proceeding of the KOSME 2001 Autumn Annual Meeting)
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• pp.88-91
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• 2001

New type of vehicles made from thin aluminum alloy are under rapid development and some product are already on the market, but when welding sheet metal joint of aluminum alloy, the main problem are burn-through by the high heat input. The purpose of this study, it is to prevent the burn-through and to shallow penetration that AC pulse welding has diminish the penetration and to lower the droplet temperature at Al sheet metal welding. In this study, we observed the bead appearance and whether it was appeared burn through or not , as the variation of the root gap in the lap and butt-joint welding process.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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• pp.153-160
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• 2002

This paper shows the possibility of performing Lap joint using the friction stir welding and the determination of tool's dimensions for FSW in Milling machine. This research also is reported on obtaining the tensile-shear strength, 9.319 ( kgf/mm$^{2}$) and the energy absorption, 2,682 (kgf-mm) under this experiment. The optimal tool's dimensions and method for Lap joint in 2tmm aluminum alloy plate using FSW is as follows; The diameter of shoulder and pin are 9 $\phi$mm and 3$\phi$mm, the length of pin is 3.6mm. The conditions of shoulder of tool is not pressed into original base metal.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.98-107
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• 2004

The objectives of this research are to establish the criteria of peel occurrence considering the shape of bond terminus and to compare the strength properties of some adhesive joints. The criteria of feel occurrence at the bond terminus was suggested. Peel loads of some adhesive joint(butt joint, T -shape specimen, single lap joint) were determined from tensile tests. Principal stress distributions of these joints were determined from finite element method analysis. Then, peel occurrence was estimated with intensity of stress singularity ' $K_{prin.}$' when the terminus shape was square, with average principal stress when the terminus shape was rounded. The conclusions are summarized as follows; (1) In the non-filleted model(e.g., butt joint, T-shape specimen), principal stress shows singularity at the bond terminus, intensity of stress(principal stress) singularity ' $K_{prin.}$&apso; can use as the criteria of peel occurrence at the bond terminus. (2) In the filleted model(e.g., single lap joint), principal stress doesn't show singularity at the bond terminus. Average principal stress can use as the criteria of peel occurrence at the bond terminus.'t show singularity at the bond terminus. Average principal stress can use as the criteria of peel occurrence at the bond terminus.

• Journal of Advanced Marine Engineering and Technology
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• 제36권8호
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• pp.1061-1068
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• 2012

오늘날 지구온난화, 환경오염 및 주요 에너지원인 화석연료의 고갈에 대한 우려가 높아지면서, 전세계적으로 신재생에너지 및 청정에너지에 대한 관심이 급격하게 증가하고 있다. 따라서 화석연료의 대체 및 SOX, NOX와 같은 오염물질을 적게 배출하는 청정에너지로써 LNG가 폭넓게 사용되고 있다. 그로인해 LNG의 소비는 급격하게 증가하고 있으며, 그것을 운반하기 위한 LNG선의 수요 또한 수십 년 동안 크게 증가하였다. 본 연구에서는 LNG선의 생산성을 향상시키기 위해 LNG선용 스테인리스강에 대한 용접에 고출력 파이버 레이저를 이용하였다. 사용된 재료는 탄소 함유량이 0.03% 이하의 STS316L이며 두께는 8mm이다. 최대출력 5kW의 파이버 레이저를 열원으로 사용하여 비초점거리, 겹치기 용접 그리고 맞대기 용접에 대한 실험을 진행하였다. 실험결과, 겹치기 용접의 경우 2.0m/min, 맞대기 용접의 경우 3.0m/min의 용접속도까지 접합이 가능하였다.

• Journal of Welding and Joining
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• 제32권6호
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• pp.70-74
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• 2014

On this study, we researched the in-process monitoring during fiber laser welding as well as on the first paper. On the previous/formal study, we analyzed the change of emission signal on thin plate welding. On this study, however, we analyzed RMS and FFT with emission signals in laser welding on lap joint and butt joint of 8mm-thick 316L stainless steel. As the result, the movement of specific frequency peak was observed according to welding speed changes. Furthermore, frequency peak as a result of FFT on the thick plate welding are much clearer than on the thin plate welding. Therefore, it is expected that the welding parameter changes can be predicted in case of applying FFT to in-process monitoring.

• 한국표면공학회지
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• 제42권6호
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• pp.294-300
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• 2009

The Friction Stir Welding (FSW) has mainly been used for making butt joints in Al alloys. The development of Friction Stir Lap Welding (FSLW) would expand the number of applications. In this study, for effective application on thin aluminum alloy lap joint, non-heat treatment A5052 alloys were joined by FSLW with the length of probe 2.3 mm and 3.0 mm. Investigating the characteristics of joint area showed the results were as below ; When the length of probe was 2.3 mm, good joint area was formed at all welding condition except for 600 rpm-700 mm/min. In the case of 3.0 mm probe length, there was formed good joint area without defects at 1500 rpm-100 mm/min. The width of joint area, position and size of defects were very important factors for FSLW, due to heat input and stirring intensity.

• Journal of Welding and Joining
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• 제20권4호
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• pp.510-516
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• 2002

Recently the laser welding technology has been applied increasingly for the automotive bodies. But the lap joint laser welding for 3 dimensional automotive body is new while the butt joint laser welding is well known as the tailored blank technology. In this study, the process window was found for the full penetration welding of the lap joint of the 1mm-thick high strength steel sheets. The limit curves and characteristic curves were suggested to define the boundaries and the contour lines in a space of the welding speed and the gap size. The characteristics of the weld sectional geometry were used to determine the limit curves. They are bead width, penetration depth and sectional area. After the observed data was analysed carefully, it was noticed that there was a transition point at which the sectional shape was changed and the bead area jumped as the welding speed was increased. Also a new concept of 'input energy Per volume' was suggested to distinguish the difference at the transition Point. The difference of sectional areas at the transition point can be related to the dynamic keyhole phenomena.

• Journal of Welding and Joining
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• 제24권3호
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• pp.22-26
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• 2006

It is necessary to investigate the welding performance and fracture resistance of welding part in structure. This study presented a most suitable condition of welding process for butt and lap joints by $CO_2$ arc welding which is widely used in the vehicle structure. Also it was conducted to tensile and fatigue test under various welding conditions. For butt and lap joints, the best conditions of welding voltage and current were 30V and 320A, respectively, in 3.2 and 4.5 mm thick steel plate. Under this condition it could be taken the highest tensile strength and fatigue strength, and a good bead appearance.

• 대한치과보철학회지
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• 제29권3호
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• pp.101-110
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• 1991

The purpose of this study was to compare the repaired joint strength among several edge profiles after denture repair. For this study, eight edge profiles were used for repair methods and five self-curing resin brands were used for repair materials. Break away loads were tested after 1 hr., 24 hrs. and 1 week. Instron was used for testing the transverse strength of repaired specimen. The results were as follows. 1. Repaired joint strength was about 35-65% of that of original specimen. 2. Joint strengths of round, inverse knife, inverse rabbit, lap ogee joint were higher tnan that of traditional simple butt joint 3. Joint strength of the simple butt joint was low significant. 4. Joint strengths after 1 hr. specimen were lower than those of 24 hrs. and 1 week specimens in joint strengths. 5. There were no significant differences between 24 hrs. and 1 week specimens in joint strengths. 6. It look more than 24 hours to gain satisfactory physical property after repairing the fractured denture base when self-curing resin was used for repair.