• Title/Summary/Keyword: Bead method

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A Study on Development of Algorithm for Predicting the Optimized Process Parameters on Bead Geometry (임의의 비드형상을 의한 최적의 공정변수 예측 알고리즘 개발에 관한 연구)

  • 김일수;차용훈;이연신;박창언;손준식
    • Journal of Welding and Joining
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    • v.17 no.4
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    • pp.39-45
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    • 1999
  • The procedure of robotic Gas metal Arc (GMA) welding in order to achieve the optimized bead geometry needs the selection of suitable process parameters such as arc current, welding voltage, welding speed. It is required the relationships between process parameters and bead geometry. The objective of this paper is to develop the algorithm that enables the determination of process parameters from the optimized bead geometry for robotic GMA welding. It depends on the inversion of empirical equations derived from multiple regression analysis of the relationships between the process parameters and the bead dimensions using the least square method. The method not only directly determines those parameters which will give the desired set of bead geometry, but also avoids the need to iterate with a succession of guesses employed Finite Element Method(FEM). These results suggest that process parameter from experimental equation for robotic GMA welding may be employed to monitor and control the bead geometry in real time.

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A Study on the Influence of the Punch Stroke of Bead on the Draw-bead process by using Static-explicit Finite Element Method (정적 외연적 유한요소법을 이용한 비드 펀치 행정거리가 드로우비드 공정에 미치는 영향에 관한 연구)

  • 정동원
    • Journal of Ocean Engineering and Technology
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    • v.15 no.2
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    • pp.72-78
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    • 2001
  • The bead is used to provide properly restraining force in the sheet metal forming process. This bead process includes bending and geometrical non-linearity, and affects the state of binderwrap. Therefore, the analysis of bead process is very important to obtain the desired formability. In this paper, the research about the influence of the punch stroke of bead on the draw-bead process was conducted. Results from the analysis will give useful information to the effective tool design of blank forming process. To analyze the bead process, and elasto-plastic finite element formulation is constructed from the equilibrium equation and the considered boundary conditions involved a proper contact condition. The static-explicit finite element method as a numerical method for the analysis was applied to the analysis program code. It was found that this method could solve too much computation time and convergence problem owing to high non-linearity of bead forming process.

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Bead Visualization Using Spline Algorithm (스플라인 알고리즘을 이용한 비드 가시화)

  • Koo, Chang-Dae;Yang, Hyeong-Seok;Kim, Maeng-Nam
    • Journal of Welding and Joining
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    • v.34 no.1
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    • pp.54-58
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    • 2016
  • In this research paper, suggest method of generate same bead as an actual measurement data in virtual welding conditions, exploit morphology information of the bead that acquired through robot welding. It has many multiple risk factors to Beginners welding training, by we make possible to train welding in virtual reality, we can reduce welding training risk and welding material to exploit bead visualization algorithm that we suggest so it will be expected to achieve educational, environmental and economical effect. The proposed method is acquire data to each case performing robot welding by set the voltage, current, working angle, process angle, speed and arc length of welding condition value. As Welding condition value is most important thing in decide bead form, we would selected one of baseline each item and then acquired metal followed another factors change. Welding type is FCAW, SMAW and TIG. When welding trainee perform the training, it's difficult to save all of changed information into database likewise working angle, process angle, speed and arc length. So not saving data into database are applying the method to infer the form of bead using a neural network algorithm. The way of bead's visualization is applying the spline algorithm. To accurately represent Morphological information of the bead, requires much of morphological information, so it can occur problem to save into database that is why we using the spline algorithm. By applying the spline algorithm, it can make simplified data and generate accurate bead shape. Through the research paper, the shape of bead generated by the virtual reality was able to improve the accuracy when compared using the form of bead generated by the robot welding to using the morphological information of the bead generated through the robot welding. By express the accurate shape of bead and so can reduce the difference of the actual welding training and virtual welding, it was confirmed that it can be performed safety and high effective virtual welding education.

Bead-to-Bead Cell Transfer by Induction of Detachment of Anchorage Dependent HeLa Cells Grown on Macroporous Microcarriers (부착성 HeLa 세포의 탈리 유도에 의한 다공성 미립담체의 담체간 전이 배양)

  • 이두훈;박정극
    • KSBB Journal
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    • v.13 no.1
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    • pp.83-89
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    • 1998
  • Using a cellulose macroporous microcarrier, HeLa cells were cultivated in 100mL spinner flask(Bellco Co., USA) and confluent cell laden microcarriers were subcultured by bead-to-bead cell transfer method. In macroporous mcirocarrier-HeLa system viable suspended cells played an important role in bead-to-bead cell transfer and that could be increased by use of RPMI-1640, a calcium-ion-reduced-media and high speed agitation. Successful bead-to-bead cell transfers were performed continuously three time in spinner flask. We applied this technique to produce recombinant Vaccinia virus which express $\beta$-galactosidase. Recombinant protein yield of bead-to-bead transferred culture was comparable to conventional microcarrier cultures that were inoculated by cells detached from T-flask. Although trypsinization is a useful method for subculturing microcarriers in some cases, that process adds quality control problem and handling steps to large scale cell production. There fore, bead-to-bead cell transfer technique offers another convenient and efficient scale-up method for continuous microcarrier cultures.

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A study on the optimized bead geometry using Taguchi method (Taguchi 방법을 이용하여 최적의 비드형상 예측에 관한 연구)

  • ;;;;Yu Xye
    • Proceedings of the KWS Conference
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    • 2003.11a
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    • pp.169-171
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    • 2003
  • In this paper, the prediction for the optimized bead geometry such as bead width, height, penetration and bead area in the Gas Metal Arc (GMA) welding with Taguchi method is presented. An orthogonal array, and the Signal-to-Noise (S/N) ratio employed to investigate the welding quality characteristics together in the selection of process parameters in the GMA welding process, to analyze the effect of each process parameter on the bead geometry and to finally determine the process parameters with the optimal bead geometry. Experimental results fi-om this research show that the Taguchi method provides an effective tool to enhance the accuracy of the optimized bead geometry.

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An Experimental study on the bond strength according to the surface treatment of metal alloy for porcelain fused metal crown (-금속(金屬) 표면처리방법(表面處理方法)에 따른 비귀금속합금(非貴金屬合金)과 도재(陶材)와의 결합강도(結合强度)에 관(關)한 실험적(實驗的) 연구(硏究)-)

  • Chung, In-Sung
    • Journal of Technologic Dentistry
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    • v.11 no.1
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    • pp.83-88
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    • 1989
  • This investigation was performed to evaluate the effect of four different preteatment techniques on the bond strength of porcelain to non-precious metal alloy. Samples of total of 40 were divided into 4 groups according to the 4 variables which included the 50$\mu$alumina oxide air abrasion, method, the as retention bead method, the L-retention bead method, the Etching method. The completed metal-porcelain samples were compressed in Instron loading machine until gross fracture occured to examine the effect of the complex variables on the bond strength of porcelain to non precious metal alloy. The result obtained were as follows : 1. The difference of bond strength according to four different pretreatment techniques was statistically significant(p<0.01). 2. The difference of bond strength between the ss-retention bead method and the L-retention bead method was not significant statistically(p>0.05) 3. The difference of bond strength between the retention bead method and the etching method was statistically significant(p<0.01). 4. The difference of bond strength between the retention bead method and the 50$\mu$alumina oxide air abrasion method was statistically significant(p<0.01). 5. The difference of bond strength between the etching method and the 50$\mu$alumina oxide air abrasion method was statistically significant(p<0.01).

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The Geometry Prediction of Back-bead in Arc Welding

  • Lee, Jeong-Ick;Koh, Byung-Kab
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.5
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    • pp.84-89
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    • 2007
  • This research was done on the basis of assumption that there is a relationship between welding parameters and geometry of the back-bead being a gap in arc welding. Multiple regression analysis was used as method for predicting the geometry of the back-bead. The analysis data and the verification data were used for the formation of multiple regression analysis. The method was used to perform the prediction of the back-bead.

A Study on the Selection of Fillet Weld Conditions by Considering the Tack Welds (가접부를 고려한 필릿 용접조건의 선정에 관한 연구)

  • Lee Jun-Yeong;Kim Jae-Yong;Kim Cheol-Hui
    • Proceedings of the KWS Conference
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    • 2006.05a
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    • pp.304-306
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    • 2006
  • Positioning the workpiece accurately and preventing the weld distortion, tack welding is often performed before main welding in the construction of welded structures. The weld bead size of the tack weld is determined according to the workpiece thickness, weld length, weld joint type etc. However, this tack weld deteriorates the final weld bead profile, so that the grinding process is usually adopted for the uniform weld bead profile. In this study, an experimental method for the selection of optimal welding condition was proposed in the fillet weld which was done over the tack weld. This method uses the response surface analysis in which the leg length and the reinforcement height of weld bead were chosen as the quality variables of weld bead profile. The overall desirability function, which was combined desirability function for the two quality variables, was used as the objective function for getting the optimal welding condition. From the result, it was revealed that a uniform weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.

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A Neural Network- Based Classification Method for Inspection of Bead Shape in High Frequency Electric Resistance Weld

  • Ko, Kuk-Won;Hyungsuck Cho;Kim, Jong-Hyung
    • Transactions on Control, Automation and Systems Engineering
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    • v.2 no.3
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    • pp.182-188
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    • 2000
  • High-frequency electric resistance welding (HERW) technique is one of the most productive manufacturing method currently available for pipe and tube production because of its high welding speed. In this process, a heat input is controlled by skilled operators observing color and shape of bead but such a manual control can not provide reliability and stability required for manufacturing pipes of high grade quality because of a variety of bead shapes and noisy environment. In this paper, in an effort to provide reliable quality inspection, we propose a neural network-based method for classification of bead shape. The proposed method utilizes the structure of Kohonen network and is designed to learn the skill of the expert operators and to provide a good solution to classify bead shapes according to their welding conditions. This proposed method is implemented on the real pipe manufacturing process, and a series of experiments are performed to show its effectiveness.

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Welding Bead Segmentation Algorithm Using Edge Enhancement and Active Contour (에지 향상과 활성 윤곽선을 이용한 용접 비드 영역화 알고리즘)

  • Mlyahilu, John N.;Kim, Jong-Nam
    • Journal of the Institute of Convergence Signal Processing
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    • v.21 no.4
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    • pp.209-215
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    • 2020
  • In this paper, we propose an algorithm for segmenting weld bead images using edge enhancement and active contours. In the proposed method, high-frequency filtering and contrast improvement are performed for edge enhancement, and then, by applying the active contour method, only the weld bead region can be obtained. The proposed algorithm detects an edge through high-frequency filtering and reinforces the detected edge by using contrast enhancement. After the edge information is improved in this way, the weld bead area can be extracted by applying the active contour method. The proposed algorithm shows better performance than the existing methods for segmenting the weld bead in the image. For the objective reliability of the proposed algorithm, it was compared with the existing high pass filtering methods, and it was confirmed that the welding bead segmentation of the proposed method is excellent. The proposed method can be usefully used in evaluating the quality of the weld bead through an additional procedure for the segmented weld bead.