• Title/Summary/Keyword: 용접변형

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Welding Deformation (1) - Characteristics and Critical Welding Length of Welding Deformation - (용접변형(1) -용접변형의 특성과 임계용접길이-)

  • 박정웅
    • Journal of Welding and Joining
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    • v.22 no.4
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    • pp.1-3
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    • 2004
  • 용접변형은 용접잔류응력과 같이 고유변형도에 의해 발생되며, 고유변형도의 분포형상에 따라 그림 1과 같은 용접변형이 발생된다. 이러한 용접변형은 강구조물 제작시 다양한 용접부형상에 의해 복합적으로 발생되며, 이것은 강구조물을 설계치수를 변화시키거나 부재 간 단차를 발생시켜 절단 또는 교정과 같은 생산공정에 불필요한 작업을 유발시켜 생산성을 저하시킨다.(중략)

Effect of Forced Cooling condition along with Welding on Welding Angular Distortion (용접 후면 강제냉각조건이 용접각변형에 미치는 영향)

  • Park, Jeong-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.4
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    • pp.2021-2026
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    • 2013
  • In this study, the effect on the welding angle distortion was reviewed by carrying out a thermal elastic-plastic analysis while changing the cooling condition(width, length, and distance from weld torch to cooling torch) the back of the welding zone for the butt weld joint. The review results revealed that maximum 57% of reduction in the angle distortion was achieved when the distance between weld torch and cooling tip of 25mm, cooling length of 80mm, and cooling width of 30mm were maintained.

Experimental Study of the Redistribution of Welding Distortion According to the Partial Removal of Welded Structure (용접구조물의 부분 제거에 따른 용접변형의 재분포에 관한 실험적 연구)

  • Kim, Yong Rae;Wang, Chao;Kim, Jae Woong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.7
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    • pp.707-712
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    • 2015
  • During the welding process, welding distortion is caused by the non-uniformity of the temperature distribution in the weldment. Welding distortion is redistributed because the residual stress and rigidity change according to the removal of the welded structure. In shipbuilding in particular, this phenomenon may be observed during the cutting process of lugs that are attached to blocks for transfer. The redistribution of welding distortion also causes problems, such as damage to the cutting tool. The aim of this study is to experimentally analyze the redistribution of welding distortion because of the partial removal of the welded structure. In the experiments conducted in this study, fillet welding and cutting were performed, and longitudinal bending and angular distortion in the welded structures were then investigated and analyzed.

The Effects of Welding Length on the Angular Distortion (용접 각변형에 미치는 용접길이의 영향)

  • 박정웅;강재완;정우현
    • Proceedings of the KWS Conference
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    • 2004.05a
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    • pp.232-233
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    • 2004
  • 강구조물 제작 시 용접프로세스에 의해 용접부 근방에 불균일한 온도분포가 발생하여 용접변형이 발생된다. 이러한 용접변형은 좌굴강도와 피로강도를 저하시킬 뿐 아니라 구조물의 크기와 형상을 변화시켜 이를 교정하거나 수정하기 위해 추가작업을 실시해야함으로 생산성을 저하시키는 주요한 요인이 되고 있다. (중략)

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용접잔류 응력과 용접변형의 발생機構와 그 대책

  • 김영식
    • Journal of Welding and Joining
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    • v.7 no.1
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    • pp.17-27
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    • 1989
  • 용접에 이와 같이 발생하는 용접잔류응력과 변형은 용접구조물의 제작시 여러 가지 장해를 유발 할 뿐만 아니고 그 구조물의 사용중에 있어서도 파괴의 발생 또는 파괴의 전파에 직.간접적으로 기여하여 악영향을 끼치게 된다. 용접잔류응력은 용접구조물의 피로감도를 저하시키거나, 취성균 열 및 응력부식균열의 진전을 용이하게 하며 용접변형은 구조물의 외관을 해치거나 국부적으로 스트레인집중을 초래하여 이 역시 취성파괴의 원인으로 작용하여 구조물의 파괴사고를 유발할 위험성을 내포하고 있다. 따라서 용접변형과 잔류응력을 극도화하기 위한 대책은 용접기술자로 서 용접시공시 유의해야 할 가장 큰 사항의 하나라고 할 수 있다. 보고에서는 이러한 용접변형 과 잔류응력현상에 대해 그 발생기구를 금속학적 측면에서 고찰하고 그 경감대책에 대해서는 구 조물의 형상이나 종류에 따라 각각별개의 대책이 수립되어야 하나 여기서는 보편적인 경우에 한 해 해설하고저 한다.

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The effect of vibratory stress conditioning on angular distortion of multi-pass butt welds (다층 용접부 각 변형에 미치는 용접 중 가진의 영향)

  • 전유철;한익승;한명수
    • Proceedings of the KWS Conference
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    • 2004.05a
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    • pp.229-231
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    • 2004
  • 다층 용접이 적용되는 후판 조립 부재에서는 각 조립단계별로 용접변형이 필연적으로 발생되고 있으며 용접변형의 교정을 위한 추가 작업도 각 조립간계 및 후 공정에서 반복적으로 수행되고 있다. (중략)

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Computational Modelling to Predict the Welding Deformation in Steel Structures (용접변형예측을 위한 용접부 수치 모델링)

  • Park, Jeong-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.1
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    • pp.96-102
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    • 2007
  • Welding deformation causes critical problems under construction and in use of steel structures by varying the magnitude of the steel structures and deteriorating mechanic strength. Existing method to construct steel structures in civil engineering needs preassembly process for a part of or the whole structures on a broad space to examine the size of structures inevitably varied in the process of welding (assembly process). It leads to waste of time, space and human efforts, worry of safety accidents with the characteristic of the work to be performed on a high place, and non-efficiency and non-economy by using such supplementary equipments as crane. This paper, to remove the needless preassembly process by pre-estimating welding deformation produced under construction of large steel structures, devises a method modeling welded part for applying the equivalence load method and examines the effects of welding sequence and self weight on welding deformation by the method.

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Analysis of the Mechanism of Longitudinal Bending Deformation Due to Welding in a Steel Plate by Using a Numerical Model (수치해석모델을 이용한 강판재의 종굽힘 용접변형 생성기구의 해석)

  • Kim, Yong Rae;Yan, Jieshen;Song, Gyu Yeong;Kim, Jae-Woong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.1
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    • pp.49-55
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    • 2017
  • Welding deformation is a permanent deformation that is caused in structures by welding heat. Welding distortion is the primary cause of reduced productivity, due to welded structural strength degradation, low dimensional accuracy, and appearance. As a result, research and numerous experiments are being carried out to control welding deformation. The aim of this study is to analyze the mechanism of longitudinal bending deformation due to welding. Welding experiments and numerical analyses were performed for this study. The welding experiments were performed on 4 mm and 8.5 mm thickness steel plates, and the numerical analysis was conducted on the welding deformation using the FE software MSC.marc.