Optimization of Weld Pitch on Overlay Welding using Mathematical Method

Kim, Ji-Sun,Kim, In-Ju,Kim, Young-Gon 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.6

It is important to overlap the even bead continuously to automate the overlay welding process. To obtain the even surface bead on overlay welded product, optimization of pitch distance between the each pass is one of the methods. Therefore, this study determines the optimal second pass pitch distance with respect to welding parameter such as torch position and welding speed. Variety of welding experiments was carried out with different welding parameters using Central Composite Rotatable Design (CCRD) method. Based on the experimental results, empirical models were developed after analyzing correlation between welding parameters and bead height, width and decentration of overlay welding. Finally, optimized empirical models were developed for predicting bead height and width by analyzing the main effect of each factor which affects bead geometry and their influence on interaction. In addition, a mathematical model was developed which determines the bead profile for visualizing the bead shapes using the Matlab curve fitting tool. These two models were combined for one of the overlay bead shape model. Furthermore, the mathematical model is then used to determine the second pass pitch distance, by allowing the same area above and below the point of interaction between two overlay weld pass.

Optimization of Weld Pitch on Overlay Welding using Mathematical Method

김지선,김인주,김영곤 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

It is important to overlap the even bead continuously to automate the overlay welding process. To obtain the even surface bead onoverlay welded product, optimization of pitch distance between the each pass is one of the methods. Therefore, this study determinesthe optimal second pass pitch distance with respect to welding parameter such as torch position and welding speed. Variety of weldingexperiments was carried out with different welding parameters using Central Composite Rotatable Design (CCRD) method. Basedon the experimental results, empirical models were developed after analyzing correlation between welding parameters and beadheight, width and decentration of overlay welding. Finally, optimized empirical models were developed for predicting bead height andwidth by analyzing the main effect of each factor which affects bead geometry and their influence on interaction. In addition, amathematical model was developed which determines the bead profile for visualizing the bead shapes using the Matlab curve fittingtool. These two models were combined for one of the overlay bead shape model. Furthermore, the mathematical model is then usedto determine the second pass pitch distance, by allowing the same area above and below the point of interaction between two overlayweld pass.

단속 필렛 용접의 변형 특성에 관한 연구

이주성(Joo-Sung Lee) 한국해양공학회 2011 韓國海洋工學會誌 Vol.25 No.6

As is well appreciated, welding is fJre most impartant fundamental process in manufacturing marine structures. However, weld-induced deformation is inevitable because of the non-uniform distribution of temperature during welding. The deformation caused by welding is one of the principal obstacles in enhancing the productivity in the manufacturing procedure for marine structures. This should be much more seriously considered in the case of the thin blocks found in a ship with multi-deck structures. This paper is concerned with the deformation control of thin panel blocks by applying intermittent welding to fillet welding. In order to investigate the quantitative effect of the intermittent welding, a thermo elasto-plastic analysis was carried out with various welding pitches and plate thicknesses. Welding tests were also carried out to show the validity of the present thermo-elasto-plastic analysis. Numerical analysis results showed good agreement with those of the welding tests. As far as the present numerical results are concerned, it has been seen that a more than 50% reduction in angular distortion can be achieved by applying the intermittent welding because of the law heat input.

KS5J32 Al합금 마찰교반접합부의 인장성질에 미치는 접합조건의 영향

윤태진,김상주,김남규,송상우,강정윤,Yoon, Tae-Jin,Kim, Sang-Ju,Kim, Nam-Kyu,Song, Sang-Woo,Kang, Chung-Yun 대한용접접합학회 2011 대한용접·접합학회지 Vol.29 No.5

The effect of welding condition on tensile properties of KS5J32 Al Alloy was investigated under various welding conditions. The 1.6 mm thick KS5J32 alloy sheets were joined by friction stir welding (FSW) technique with butt joint. The tool rotation speeds were 1000, 1250 and 1500 rpm, and the welding speeds were varied within the range from 100 to 600 mm/min. Voids mainly occurred at the advancing side of the tool probe, when the tool rotation speed was low, due to insufficient materials flow. When the weld pitch exceeded 0.4 mm/rev, voids were observed under all welding conditions and the area of voids increased with increasing weld pitch. For void-free specimens, fracture always occurred at base materials. However voids affected the location of fractures, base metal or welded zone, when the voids existed within the welds.

차체구조용 SCP1 강도부재의 점용접간격이 압궤특성에 미치는 영향

차천석,박제웅,양인영 대한용접접합학회 2002 대한용접·접합학회지 Vol.20 No.6

Front-side members are structures with the greatest energy absorbing capability in a front-end collision of vehicles. This paper was performed to analyze initial collapse characteristics of spot welded hat and double hat-shaped section members, which are basic shape of side members, on the shift of flange weld pitches. The impact collapse tests were carried out by using home-made vertical air compression impact testing machine, and impact velocity of hat-shaped section members is 4.17m/sec and that of double hat-shaped section members is 6.54m/sec. In impact collapse tests, the collapsed length of hat-shaped section members was about 45mm and that of double hat-shaped section members was about 50mm. In consideration of these condition, axial static collapse tests(0.00017m/sec) of hat and double hat-shaped section members were carried out by using UTM which was limited displacement, about 50mm. As the experimental results, to obtain the best initial collapse characteristics, it is important that stiffness of vehicle members increases as section shapes change and the progressively folding mode induces by flange welding pitch.

Effects of the shoulder diameter and weld pitch on the tensile shear load in friction-stir welding of AA6111/AA5023 aluminum alloys

Park, Sang-Won,Yoon, Tae-Jin,Kang, Chung-Yun Elsevier 2017 Journal of materials processing technology Vol.241 No.-

<P>The heights of deformed interface and surface affected the tensile shear load of lap joints fabricated by friction stir welding. The influences of shoulder diameter, weld pitch and evolution of mechanical properties has been investigated experimentally. The heights of the softened surface decreased and the bonded area widened with increasing the SD. The interface transformed from a hooked shape to a flat interface with decreasing the WP. The peak load was obtained by increasing the SD and WP. Fractured positions were divided in two types, shear and tensile fracture. Shear fracture occurred at the interface which contains stir zone. Tensile fracture was observed at the thermo-mechanically affected zone of the top plate. The fracture mode indicating the peak load was the shear fracture rather than tensile fracture. This is because the exact position of shear fracture was where the base material penetrated the bottom plate. The larger SD and higher WP produced higher peak load because of widened bonded area and little deformation. But the peak load decreased inversely in case of the higher rotation speed over than 1500 rpm which means higher heat input conditions. (C) 2016 Elsevier B.V. All rights reserved.</P>

음향방출법에 의한 저항 점용접부의 파괴특성에 대한 연구

조대희(Dae-Hee Jo),이장규(Zhang-Kyu Rhee),박성완(Sung-Oan Park),김봉각(Bong-Gag Kim),우창기(Chang-Ki Woo) 한국생산제조학회 2007 한국생산제조학회지 Vol.16 No.2

In this paper, the acoustic emission(AE) behaviors were investigated with single- and 2-spot resistance spot welded SPCC specimens. Test specimens were welded horizontally and/or vertically according to the rolling direction of base metal in 2-spot welding. In the case of 2-spot welding, when tensile-shear test has below amplitudes: crack initiation 50~60㏈; tear fracture 40~50㏈. And when cross tensile test has below amplitudes: early stage 75~85㏈; yielding point 65~75㏈; post yielding 40~60㏈; plug fracture 70~80㏈ or 90~100㏈. Also, from the b-value that is slope of AE amplitude, we knew that there are lots of low amplitudes if b-value is big(i.e., tensile-shear specimen→tear fracture or shear fracture), and there are lots of high amplitudes if b-value is small(i.e., cross tensile specimen→plug fracture). As the results of fracture mechanism analyses through AE amplitude distributions, change of the b-value represented fracture patterns of materials. Correspondingly, low amplitude signals appeared in crack initiation, and high amplitude signals appeared in base metal fracture. We confirmed that these amplitude distributions represented the change or degradation of materials.

PITCH계 탄소섬유 스티칭이 열가소성 복합재 전도 용접 접합부에 미치는 영향

노영덕(Yeong-Deok Noh),정원량(Won-Ryang Jeong),권진회(Jin-Hwe Kweon),곽병수(Byeong-Su Kwak) 한국항공우주학회 2023 한국항공우주학회 학술발표회 논문집 Vol.2023 No.11

Collapse Analysis of Spot Welded Thin Section Members in a Vehicle Body Structure at Various Impact Velocities

Cha, Cheon-Seok,Chung, Jae-Oh,Park, Jae-Woung,Kim, Young-Nam,Yang, In-Young The Korean Society of Mechanical Engineers 2003 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.17 No.4

The spot welded sections of automobiles such as the hat and double hat section members, absorb the most of the energy during the front-end collision. The purpose of this study was to analyze the collapse characteristics of spot welded section members with respect ttl the pitch or spot welds on flanges. through impact experiments and computation for para-closed sections and perfectly closed sections. The hat shaped section members were tested at the impact collapse velocities of 4.72 m/sec, 6.54 m/sec and 7.19 m/sec and double hat shaped section members were tested at the impact collapse velocities of 6.54 m/sec, 7.19 m/sec and 7.27 m/sec. A commercial LS-DYNA3D was used to simulate the collapse behavior of the hat and double hat shaped section members. The validity of the simulation was to be proved by comparing the simulation results and the experimental results.

피치 가변형 경량 트윈 점 용접 시스템

이소영(Soyoung Lee),유성필(Sungphil Ryu),조용준(Yongjoon Cho),장인성(Insung Jang) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

While resistance spot welding (RSW) has been the most successful sheet metal joining process in automotive industry, there are certain limitations due to achieve high productivity. In this research, an automated variable pitch spot welding system is introduced to overcome typical RSW issues and its applications to automotive body assembly are presented. Various applications for body-in-white were investigated. Door opening areas were joined together with a specially designed twin welding gun. Thanks to the double weld spots of the machine, high productivity can be achieved as a fault-free weld for the body-in-white panels.