• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 추계학술발표대회 개요집
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• pp.245-247
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• 2003

Elements of Pure Weld Metal(PWM) is important factor that understand to analyze Flux's conduct in SAW welding. For elements of PWM were got, Pile-up welding over 10 floor have used in the past. But, it take a long time to analyze elements of PWM in this method. Elements of Pure Weld Metal is needed to seize more easily. In this research, Bead welding is used to graps an element of Pure Weld Metal using mathematical formula which get to be derivation.

• 한국정밀공학회지
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• 제12권9호
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• pp.86-94
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• 1995

Bead shape in high frequency electric resistance (HER) pipe welding gives useful information on judging current welding conditon. In most welding process, heat input is controlled by skilled operators observing color and shape of bead. In this paper, a visual monitoring system is designed to observe bead shape in HERW pipe welding process by using structured light beam and a C.I.D(Charge injection device) camera. To avoid some difficul- ties arising in extracting stable features of stripe pattern and classifying the extracted features, Kohonen neural network is used to classify such bead shapes. The experimental results show accurate classification performance of the proposed method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.49-54
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• 2001

Measurement of welding residual stresses is one of important tasks to assess the structural integrity of welded structures. For operating components, especially, nondestructive techniques are required. By now, authors have proposed a new residual stress evaluation method, the bead flush method, where residual stresses are calculated from eigenstrain distribution determined by surface removal of reinforcement. In this paper, a brief description of the bead flush method is given and its utility and problem to be overcome are discussed. And also stabilization method of solution set of eigenstrain in inverse analysis is proposed.

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.137-146
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• 2008

Nd:YAG pulse laser welding of stainless steel plate was simulated to find welding condition by using commercial finite element code MARC. Due to geometric symmetry, a half model of AISI 304 stainless steel plate was considered and user subroutines were applied to boundary condition for the heat transfer. Material properties such as conductivity, specific heat, mass density and latent heat were given as a function of temperature. As results, Three dimensional heat source model for pulse laser beam conditions of butt welding has been designed by the comparison between the finite element analysis results and experimental data on AISI 304 stainless steel plate. Nd:YAG laser welding for AISI 304 stainless steel was successfully simulated and it should be useful to determine optimal welding condition.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.192-197
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• 2005

A welding bead height is closely related to the efficiency of welding work, and the height of 3mm is used in the conventional practice of butt welding. in the present paper, the modification of bead height from 3mm to 6mm is considered to increase the efficiency and work productivity of butt welding on bottom plate (of BONGA FPSO actually built in SHI shipyard). Therefore, fatigue analysis has been carried out using simplified method based on the DNV Rules. It is found that the minimum fatigue life is about 594 years and the butt welding details with 6mm bead height has sufficient strength and resistance against fatigue.

• Journal of Welding and Joining
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• 제15권6호
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• pp.116-123
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• 1997

In GMA welding processes, bead contour and penetration patterns are criterion to estimate weld quality. Bead geometry is commonly defined with width, height and depth. When weaving is taken into account, selection of welding conditions is known to be difficult. Thus, empirical or trial-and-error method are usually introduced. This study examined the correlation of welding process variables including weaving parameters with bead geometry using srtificial neural networks(ANN). The main task of the Ann estimator is to realize the mapping characteristics from the sampled welding process variables to the actual bead geometry through training. After the neural network model is constructed, welding process variables for desired bead geometry is selected by inverse model. Experimental varification of the inverse model is conducted through actual welding.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2011년도 춘계학술대회
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• pp.355-358
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• 2011

방충재(fender)는 항만에서 선박의 안전한 접이안, 계류, 안벽 보호를 하기 위하여 설치된 중요한 안벽 시설 중 하나이다. 기존의 고무 방충재는 접안력에 의한 초기 변형 28% 정도에서 가장 높은 반력이 발생하기 때문에 선박과 안벽에 지속적인 힘을 주기 때문에 안벽 및 선체에 손상을 주고 있다. 이는 잔교식이나 중력식 부두에서도 나타나는 현상이다. 또 선체의 용접 비드에 의하여 방충재 훼손으로 보수 유지비가 증가하고 안벽에 앵커로 고정된 고무 펜더는 유연성이 떨어져 선박 충격에 의한 쉽게 떨어지고 패널패드도 탈락된다. 이 연구에서는 초기 반력이 적은 에어 펜더 혹은 폼 펜더를 제안한다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2012년도 전기공동학술대회 논문집
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• pp.171-171
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• 2012

• 한국해양공학회지
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• 제24권4호
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• pp.38-46
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• 2010

The wall thinning phenomenon of pipes was simulated as metal loss due to erosion and corrosion. Such wall thinning defects in the pipes of power plants are a very important safety consideration. In this study, we analyzed wall thinning defects that occurred by weld bead of weld zone of boost pump recirculation pipe. From the results of the analysis of pipe failures, numerical analysis was performed by Fluent v6.3.26 using the standard k-$\varepsilon$ model of the weld bead shape, such as an elliptical or a spherical shape, on the inner wall of the pipe. Using the results obtained, we showed the overlap effect by cavitations corrosion and erosion-corrosion at the bottom of the wall-thinning defect.

• 한국공작기계학회논문집
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• 제16권1호
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• pp.60-68
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• 2007

It has been conducted by laser vision sensor for weldability estimation of front-bead after doing high speed butt laser welding of any condition. It has been developed a real time GUI(Graphic User Interface) system for weldability application in the basis of texts and field qualify levels. In the reference of bead imperfections, defects absolute position and defects intensity index of front-bead in the basis of formability reference, it has been produced a weldability estimation and defects intensity index of back-bead by back propagation neural network. In the result of by comparing measuring data by laser vision sensor of back-bead and data by back propagation neural network of one, it has been shown the similar results. Finally, under knowledge of welding condition in production line, it has been conducted a weldability estimation of back-bead only in knowledge of informations of front-bead data without using laser vision sensor or welding inspection experts and furthermore it can be used data for final inspection results of back-bead.