• 제목/요약/키워드: Butt weld

검색결과 264건 처리시간 0.025초

강교량 맞대기용접 결함부의 피로수명 평가 (Fatigue Life Assessment of Steel Bridge Butt Joint Weld with Defects)

  • 백영남;장영권
    • Journal of Welding and Joining
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    • 제18권2호
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    • pp.204-204
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    • 2000
  • There are many weld defects such as surface crack, lack of fusion, and incomplete penetration(IP) in the butt joint weld of the existing steel bridges. The crack-like defects may significantly reduce the life of the structure. This paper presents the procedure and the results of the fatigue life assessment of the butt joints with weld defects in the existing steel girder bridge. The butt joint welds with incomplete penetration were instrumented with strain gages to determine the stress histogram under normal traffic. Based on the measured stress histogram the crack propagation analysis were performed for the fatigue life assessment. By using the suggested procedure and methodology, one can decide the time of periodic inspection and the necessity of repair of the butt joint welds with serious weld defects in the existing steel bridge. (Received October 1, 1999)

강교량 맞대기용접 결함부의 피로수명 평가 (Fatigue Life Assessment of Steel Bridge Butt Joint Weld with Defects)

  • 백영남;장영권
    • Journal of Welding and Joining
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    • 제18권2호
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    • pp.77-85
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    • 2000
  • There are many weld defects such as surface crack, lack of fusion, and incomplete penetration (IP) in the butt joint weld of existing steel bridges. The crack-like defects may significantly reduce the fatigue life of the structure. This paper presents the procedure and the results of the fatigue life assessment of the butt joints with weld defects in the existing steel girder bridge. The butt joint welds with incomplete penetration were instrumented with strain gages to determine the stress histogram under normal traffic. Based on the measured stress histogram the crack propagation analysis were performed for the fatigue life assessment. By using the suggested procedure and methodology, one can decide the time of periodic inspection and the necessity of repair of the butt joint welds with serious weld defects in the existing steel bridge.

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용접 비드 형상을 이용한 용접 시편의 피로수명 예측 연구 (A Study on the Fatigue Life Estimation Using Butt Weld Bead Profiles)

  • 김재훈;구병춘
    • 한국철도학회논문집
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    • 제7권2호
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    • pp.125-129
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    • 2004
  • This study investigates the fatigue lift estimation of butt weld specimen for the railway vehicle by examining butt weld bead profiles. The butt weld beads, which are welded by semi-robot method, have non-uniform bead profiles described by $\theta$, p and h. The stress concentration factors, K$\_$t/, are changed by different $\theta$, p and h from 1.395 to 2.863. Hence, the sensitivity of K$\_$k/ is changed by each $\theta$, p and h. As $\theta$ becomes lower and p and h become higher, K$\_$t/ increases. The fatigue life can be estimated very closely for the AAY specimens without residual stress using only butt weld bead profiles. But, for the AAN specimens with residual stress, the fatigue life must be estimated by considering both the weld bead profiles and the residual stress data.

철도 구조물용 맞대기 용접시편 가공에 의한 피로수명 영향 및 용접부 형상을 이용한 피로수명 예측 연구 (A Study on the Effects of the Fatigue Life due to the Processing of the Butt Weld Specimens and the Fatigue Life Estimation due to the Weld Zone Profiles)

  • 김재훈
    • 한국철도학회논문집
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    • 제9권4호
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    • pp.371-378
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    • 2006
  • This study investigates the effects of the material properties and the fatigue behaviors in the SM490A material butt weld specimens due to the heat-treatment and the grinding. In the fatigue behavior, the heat-treatment affects the fatigue life. The S-N curves of both matrix specimen and butt weld specimen are reversed at some cycle by the existence or nonexistence of heat-treatment. The grinding on the bead makes the fatigue limit decrease in the all specimens. But the reinforcement removed, the fatigue limit increases at the high cycle. Also, this study investigates the fatigue life estimation by examining butt weld bead profiles. The butt weld beads, which are welded by semi-robot method, have non-uniform bead profiles described by $\theta,\;\rho$ and h. The stress concentration factors $K_t$, are changed by each different $\theta,\;\rho$ and h from 1.395 to 2.863. Hence, the sensitivity of $K_t$ is changed by each $\theta,\;\rho$ and h. As $\theta$ becomes lower and $\rho$ and h become higher, $K_t$ increases. The fatigue life can he estimated very closely for the AAY specimens without residual stress using only butt weld bead profiles. But, fur the AAN specimens with residual stress, the fatigue life must be estimated by considering both the weld bead profiles and the residual stress data.

교량의 피로강도를 고려한 맞대기용접부 불안전용입 한계결함 결정에 관한 연구 (An Experimental Study on Allowable Size of Incomplete Penetration in Butt Joint Bridge Weld Considering Fatigue Strength)

  • 백영남;장영권
    • Journal of Welding and Joining
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    • 제18권3호
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    • pp.68-75
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    • 2000
  • The incomplete penetration(IP) discontinuity in butt joint weld, which is detected during safety analysis of the steel bridge by nondestructive evaluation(NDE) method, is classified as unacceptable defect according to the NDE codes and standards. In fact, there are a little allowance in butt joint weld in the view point of design criterion, and also detected IP discontinuity should be classified and evaluated for the fatigue strength and residual life estimation. In this study, we performed fatigue test to evaluate the fatigue strength of high strength steel(SWS490A) containing IP discontinuities in various size, the results compared and classified according to the bridge construction standard specification which published by korea administration of construction and traffic. Experimental results could be used to evaluate and estimate the IP discontinuities considering different stress range in butt joint bridge weld during periodic safety inspection.

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강교 용접 결함부의 피로평가 (Fatigue Assessment of Butt Joint with Weld Defect in Steel Bridge)

  • 전귀현
    • 한국구조물진단유지관리공학회 논문집
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    • 제2권1호
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    • pp.98-107
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    • 1998
  • There are many weld defects such as surface crack, lack of fusion, and imcomplete penetration in the butt joint of the existing steel bridges. The crack-like defects may significantly reduce the fatigue life of the structure. This paper presents the procedure and the results of the fatigue assessment of the butt joints with weld defect in the existing steel girder bridge. The butt joints with imcomple penetration were instrumented with strain gages to determine the stress histogram under normal traffic. Based on the measured stress histogram the crack propagation analyses were performed for the fatigue assesment. By using the suggested procedure and methodology, one can decide the time of periodic inspection and the necessity of repair of the butt joints with serious weld defects in the existing steel bridge.

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Study on fatigue experiment for transverse butt welds under 2G and 3G weld positions

  • Kang, Sung-Wook;Park, Yong-Man;Jang, Beom-Seon;Jeon, Yu-Chul;Kim, Seong-Min
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제7권5호
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    • pp.833-847
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    • 2015
  • Although the transverse butt weld method with ceramic backing strip has been widely used in various industrial fields for its fabricational convenience, it is rarely used in offshore industries since the fatigue strength of the weld joint has not been proved sufficiently. This study conducted fatigue tests for series of butt weld specimens with horizontal (2G) and vertical (3G) welding positions in order to verify the fatigue strength compared to S-N curve by DNV (Det Norske Veritas), IIW (International Institute of Welding) and Eurocode 3. The difference of the 2G specimens and the 3G specimens are investigated in terms of angular distortion and the effect on the fatigue strength are analyzed.

이종재이종재료 Butt 용접에 대한 Overlay 용접의 잔류응력해석 (Residual Stress Analysis of the Overlay Weld on the Dissimilar Metal Butt Weld)

  • 김강수;이호진;이봉상;정인철;변진귀;박광수
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.534-537
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    • 2008
  • In recent years, the dissimilar metal, Alloy 82/182 welds used to connect stainless steel piping and low alloy steel or carbon steel components in nuclear reactor piping system have experienced cracking due to primary water stress corrosion(PWSCC). It is well known that one reason of the cracking is the residual stress by the weld. But, it is difficult to estimate exactly weld residual stress due to many parameters of welding. In this paper, the analysis of 3 FEM models made by ABAQUS Code is performed to estimate exactly the weld residual stress on the dissimilar metal weld. 3 FEM models are Butt model, Repair model and Overlay model and are the plane.strain 2D model. The thermal analysis and the stress analysis are performed on each model and the residual stresses on each model were calculated and compared respectively. Also, the specimen of Butt model was made and the residual stresses were measured by X-Ray method and Hole Drilling Technique. These results were compared with the FEM result of Butt model.

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마찰교반용접된 겹치기 및 맞대기 용접부 특성에 대한 실험 (Experimental Behaviors of Weld Zone Property of the Butt and the Lap Jointed Specimen Friction-Stir-Welded with 2mmt 1050 Aluminum Alloy Sheet)

  • 전정일;장석기
    • 대한기계학회논문집A
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    • 제30권2호
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    • pp.187-193
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    • 2006
  • The butt and the lap welding by friction stir welding performs with $2mm^t$ 1050 aluminum alloy sheet. This paper shows behaviors of property such as vickers hardness, yielding and ultimate stresses, and macro structures for weld zone cross section of the butt and the lap jointed specimens. It is also carried out making comparison with maximum loads, stress-strain diagrams, and deformation after the guided bending test and fracture behaviors between the butt and the lap jointed specimens. It is found that the weldability of the butt jointed specimen is better than that of the lap jointed specimen.

결함 평가에서 용접 잔류응력 분포의 영향 (Effect of Residual Stress Distributions in Defect Assessment)

  • 이세환;이형연;김종범;이재한
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2006년 추계학술발표대회 개요집
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    • pp.15-17
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    • 2006
  • Weld residual stresses can be a major concern in structural integrity assessments such as a nuclear power plant. In this paper, detailed weld residual stress analyses were presented for a typical multi-pass weld of pipe-butt weld and plate T-butt weld. The calculated residual stress distributions were compared with those of the measured data and recommended profiles in R6 and BS7910. Defect assessment which is based on the stress intensity factor(SIF) calculations was carried out for a plate T-butt weld with cracks considering the weld residual stress distributions.

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