• Title/Summary/Keyword: arc length

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Nonlinear Analysis Method by the Arc Length Method (Arc Length Method에 의한 비선형 문제의 해법)

  • 이대희;최종근
    • Computational Structural Engineering
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    • v.9 no.3
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    • pp.107-114
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    • 1996
  • The performance for the algorithm of the arc length method has been examined in terms of the choice of the tangential stiffness matrix through the analysis for the snap buckling phenomenon of the arch beam. The curved beam element with 2 nodes including shear effect has been formed by strain element technique and then it has been used in this nonlinear analysis. Snap-through characteristics has been examined with respect to the ratios of the arch beam length to hight.

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The Development of Welding Process to Prevent Porosity in MIG Welding of Al 6082-T6 (Al 6082-T6 MIG 용접에서 기공방지를 위한 용접공정 개발)

  • Baek, Sang-Yeub;Jung, Yon-Ho;Kim, Won-Il;Cho, Sang-Myung
    • Journal of Welding and Joining
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    • v.28 no.6
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    • pp.28-34
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    • 2010
  • This paper was described on investigation to prevent porosity in high speed MIG Welding of Al 6082-T6. Porosity measurement was carried out by using image analysis of micrographs with the help of an analysis software. The main parameter was arc length and torch progressive angle. The porosity ratio was increased as arc length was increased. The arc length was increased depending upon the output voltage. By proper selection of pulse waveform parameter, the stable arc of one pulse one drop was generated. The porosity ratio of optimum condition in one pulse one drop was lower than high voltage condition. When torch progressive angle was an angle of advance $10^{\circ}$, porosity ratio was minium.

A study on the A.C. arc movement in a transverse A.C. magnetic field at atmospheric pressure (황축교류자계에 의한 대기중에서의 교류 아아크의 이동에 관한 연구)

  • 전춘생;엄기환
    • 전기의세계
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    • v.24 no.6
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    • pp.77-84
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    • 1975
  • This paper treats A.C. arc movement in a transverse A.C. magnetic field at atmospheric pressure with the purpose of selecting electrode materials and obtaining detailed data for design of A.C. air circuit breaker, plasma accelerator and plasma jet. Arc velocities in transverse magnetic field are measured by varying arc current, arc voltage, gap length, magnetic flux density and the erosion of electrode surface, which influence arc velocities. The main results are; 1)Arc velocities in transverse magnetic field have different values according to electrodes of various materials and decrease in a descending order of cold cathode, medium cathode and hot cathode. 2)Arc velocities in transverse magnetic field increases with arc current, arc voltage, gap length and magnetic flux densith and on the other hand decrease with the increase of electrode surface erosion. 3)D.C.arc velocity in D.C. magnetic field is higher than A.C. arc velocity in A.C. magnetic field of the same value.

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An Influence Arc Shield having on to Electric-field in the VI insides (VI 내부에서 Arc shield가 전계에 미치는 영향)

  • Yoon, Jae-Hun;Kim, Beung-Chuel;Lee, Sung-Su;Lim, Kee-Jo;Kang, Seong-Hwa
    • Proceedings of the KIEE Conference
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    • 2008.04c
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    • pp.247-248
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    • 2008
  • This paper describes the influence of shield(Arc shield) on the electric fields in a vacuum interrupter(VI). The equipotential line and electric field in a VI are analysed by a finite element method at various shield length. in result, The electric potentials of Arc shield edge was increased because the length too short or long approach the source. it confirmed that equipotential line was influenced that shape and length by end shield. finally this pater proposed to optimal length and shape by arc shield.

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The Eeffect of Arc Length and Shield Gas on Penetration Aspect Ratio in A-TIG Welding (A-TIG 용접에서 용입 형상비에 미치는 아크길이와 실드가스의 영향)

  • Park, In-Ki;Ham, Hyo-Sik;Cho, Sang-Myung
    • Journal of Welding and Joining
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    • v.26 no.6
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    • pp.42-47
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    • 2008
  • TIG welding enables to produce high quality weldment. However it has some problems such as shallow penetration and large distortion due to low penetration aspect ratio after welding. In order to overcome those problems, there are many ongoing studies on A-TIG welding, which use active flux. In this study, the effect of arc length and shield gas on penetration aspect ratio with melt-run welding on STS 304 6t, on which active flux was spreaded, was investigated. Arc length was changed from 1mm to 3mm, and aspect ratio became higher as arc length was decreased in this range. 100% Ar gas, Ar-$H_2$ mixed gas, Ar-He mixed gas, and 100% He gas were used as shield gas in this study. When Ar-$H_2$ mixed gas, Ar-He mixed gas, and 100% He gas were applied, penetration and melting efficiency were both increased as compared with 100% Ar gas. Aspect ratio was the highest with Ar-2.5% $H_2$ mixed gas.

The Effect of Process Variables on Mechanical Properties and Formability in GTA Welds of Commercial Pure Titanium Sheet (순 Ti 박판 GTA 용접부의 기계적 성질 및 성형성에 미치는 공정변수의 영향)

  • Kim, Jee-Hoon;Hong, Jae-Keun;Yeom, Jong-Taek;Park, Nho-Kwang;Kang, Chung-Yun
    • Journal of Welding and Joining
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    • v.28 no.4
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    • pp.73-80
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    • 2010
  • In this work, the effect of welding variables on weldability of gas tungsten arc(GTA) welding was investigated with experimental analysis for a commercial pure(CP) titanium (Grade.1). The GTA welding tests on sheet samples with 0.5mm in thick were carried out at different process variables such as arc length, welding speed and electrode shape. In order to search an optimum arc length with full penetration, bead- on-plate welding before butt-welding were performed with different arc length conditions. From the bead- on-plate welding results, the optimum condition considering arc stability and electrode loss was obtained in the arc length of 0.8mm. Butt-welding tests based on the arc length of 0.8mm were carried out to achieve the optimum conditions of welding speed and electrode shape. Optimum conditions of welding speed and electrode shape were suggested as 10 mm/s and truncated electrode shape, respectively. It was successfully validated by the microstructural observation, tensile tests, micro-hardness tests and formability tests.

The Characteristics of Magnetic Field in Multi-Torches FCAW (다전극 FCAW의 전극 간격에 따른 자기장 특성)

  • Go, Seong-Hun
    • Proceedings of the KWS Conference
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    • 2005.06a
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    • pp.69-70
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    • 2005
  • In order to prevent the arc blow at the FCA welding system with multi-torches, the effects of arc length on the magnetic flux at the FCA weldment was evaluated using electro-magnetic filed analysis. Magnetic flux density around arc are slightly increased with an increase in the arc length. Based on the FEA results, the minimum distance of torches to control arc blow was established.

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A Study of Seam Tracking and Error Compensation for Plasma Arc Welding of Corrugation Panel

  • Yang, Joo-Woong;Park, Young-Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2701-2706
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    • 2003
  • This paper describes weld seam tracking and error compensation methods of automatic plasma arc welding system designed for the corrugation panel that consists of a linear section and a curved section with various curvatures. Realizing automatic welding system, we are faced with two problems. One is a precise seam tracking and the other is an arc length control. Due to the complexity of the panel shape, it is difficult to find a seam and operate a torch manually in the welding process. So, laser vision sensor for seam tracking is equipped for sensing the seam position and controlling the height of a torch automatically. To attain more precise measurement of an arc length, we measure the 3D shape of the panel and analyze error factors according to the various panel states and caused errors are predicted through the welding process. Using that result, compensation algorithm is added to that of arc length control and real time error compensation is achieved. The result shows that these two methods work effectively.

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A Study on Dynamic Characteristics of Welding Current and Arc Length At GMAW (GMA용접에서 용접전류와 아크 길이의 동특성에 관한 연구)

  • Lee, Tae-Young
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.1
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    • pp.15-21
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    • 2011
  • Welding variables and conditions in gas metal arc welding (GMAW) effect on the quality and productivity of the weld, extensive research efforts have been made to analyze the effect of the welding variables and conditions. In this study dynamic behavior of GMAW system is investigated using the characteristics of the power supply, wire and welding arc. Characteristic equation of wire is modified to include the effect of droplets attached at the electrode tip. The dynamic characteristics of arc length, current, voltage with respect to the step, ramp inputs of CTWD was simulated. From results of simulation, some predictions about dynamic characteristics of GMAW and welding process are available. The proposed simulator and results appear to be utilized to determine the proper welding conditions, to be improved by considering power supply dynamic characteristics.

Free Vibrations of Hinged-Hinged Arches with Constant Arc Length (일정한 곡선길이를 갖는 양단회전 아치의 자유진동)

  • Lee, Byoung-Koo;Lee, Tae-Eun;Kim, Gwon-Sik;Yoon, Hee-Min
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.46-49
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    • 2008
  • This paper deals with the free vibrations of elastica shaped arches with constant arc length. The elastica shaped arches are formed by the post-buckled column whose arc length is always constant. The equations governing free, in-plane vibration of general arch in open literature are modified for applying the free vibrations of elastica shaped arch and solved numerically to obtain frequencies and mode shapes for hinged-hinged end constraints. The effects of rotatory inertia, rise to span length ratio and slenderness ratio on natural frequencies are presented. The frequencies of elastica and parabolic shaped arches are compared. Also, typical mode shapes are presented in figures.

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