• 대한조선학회논문집
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• 제33권3호
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• pp.1-7
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• 1996

용접이음부재에서 피로강도에 큰 영향을 미치는 용접부의 응력집중계수를 추정하였다. 여기서는 하중전달형 십자필렛용접이음부를 그 대상으로 하였다. 필렛용접이음부에서 토우파괴를 일으키는 피로균열발생부인 용접토우부의 응력집중계수를 구하기 위해 인장하중하에서 토우부의 적정 요소 크기를 검토하고 여러 파라메타들의 값을 변화시켜 유한요소 응력해석을 수행하였다. 즉 용접토우부의 형상인 토우각 및 곡률반경의 영향과 용입부족부 길이의 변화를 동시에 고려한 응력집중계수를 정량적으로 구하였다. 그리고 그 결과를 이용하여 응력집중계수 추정식을 유도하였다.

• Journal of Welding and Joining
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• 제32권1호
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• pp.61-65
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• 2014

The purpose of this study is to evaluate the applicability of the element stress to establish S-N design curve for the welded lap joint with thin plates below 2mm thickness. In order to do it, the extensive fatigue tests of the welded lap joints with INVAR alloy were performed. With the results, the deign S-N curves for the lap-weld were established by using the reference stresses such as the nominal stress range at the weld throat area, hot spot stress range and element stress range, and compared with regard to the standard deviation. The standard deviation of S-N curves with element stress range was less than that of S-N curves with other reference stresses. In addition, FEA results show the amount of the element stress is less sensitive to mesh size. Based on the results, it can be concluded that the element stress is to be used as the reference stress for the design S-N curves of the welded lap joint.

• 대한기계학회논문집
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• 제10권5호
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• pp.625-634
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• 1986

본 연구에서는 알루미늄 합금인 알루미늄 2014와 6061의 이재를 V형 맞대기 이음을 한 후 정적인장하중을 가하여 모아레법에 광탄성 피복법을 조합한 방법에 의 해 변형율을 실시간(real time)에서 측정하고 유한요소법으로 해석한 결과와 비교검 토하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년 추계학술발표대회 개요집
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• pp.29-31
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• 2006

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds structures used stainless steel sheets are commonly fabricated by using the gas welding. For fatigue design of gas welded joints such as fillet and plug type joint, it is necessary to obtain design information on stress distribution at the weldment as well as fatigue strength of gas welded joints. And also, the influence of the geometrical parameters of gas welded joints on stress distribution and fatigue strength must be evaluated. the ${\Delta}P-N_f$ curves were obtained by fatigue tests. Using these results, ${\Delta}P-N_f$ curves were rearranged in the ${\sigma}-N_f$ relation with the maximum stress at the edge of fillet welded joint.

• 한국자동차공학회논문집
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• 제18권4호
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• pp.127-131
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• 2010

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds of structures used stainless steel sheets are commonly fabricated by using the gas welding. For fatigue design of gas welded joints such as fillet and plug type joint, it is necessary to obtain design information on stress distribution at the weldment as well as fatigue strength of gas welded joints. And also, the influence of the geometrical parameters of gas welded joints on stress distribution and fatigue strength must be evaluated. Thus, in this paper, ${\Delta}P-N_f$ curves were obtained by fatigue tests. Using these results, ${\Delta}P-N_f$ curves were rearranged in the. ${\Delta}{\sigma}-N_f$ relation with the hot spot stresses at the gas welded joints.

• 대한조선학회지
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• 제18권4호
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• pp.21-29
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• 1981

In this paper, plastic behavior and plastic strength of cruciform fillet welded joint under tension is investigated by finite element method. Attension is focussed, in particular, on the effect of geometry of fillet weld including its contour, size and penetration. And the approximate analysis of welded joint have been carried out from a simple model constructed by three zone, ie, base metal, heat affected zone, and weld metal.

• 국제강구조저널
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• 제18권5호
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• pp.1631-1638
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• 2018

In the periodic repainting of steel bridges, often the steel surface has to be prepared by using power tools to remove surface contaminants, such as deteriorated paint film and rust, and to increase the adhesive strengths of the paint films to be applied newly. Surface preparation by bristle roll-brush grinding, which is a type of power tool, may additionally introduce compressive residual stress and increase the fatigue resistance of welded joints owing to the impact of rotating bristle tips. In this study, fatigue tests were conducted for longitudinally out-of-plane gusset fillet welded joints and transversely butt-welded joints to evaluate the effect of bristle roll-brush grinding prior to repainting on the fatigue resistance of the welded joints. The test results showed that bristle roll-brush grinding introduced compressive residual stress and significantly increased fatigue limits by over 50%.

• Journal of Welding and Joining
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• 제30권6호
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• pp.62-67
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• 2012

In this study, the bonding strengths of adhesively bonded joints are experimentally investigated. A series of lap-shear tests are conducted using single lap type adhesive joints. In order to analyse the joint fabrication factors that affected the bonding strength, the parametric tests are conducted with various thickness of adhesive, surface roughness and fillet of adhesive. In addition, for the comparative study with the welded joint, lap-shear tests using specimens with 2 welded sides and 4 welded sides are also carried out. The quantitative results of the strength analysis are summarized, and some proposals are made on setting up testing standards for adhesively bonded joints.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.314-318
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• 2004

This research is conducted to investigate weldability characteristics with various welding conditions on the 4 lap spot welded joint of structural steel sheets in automobile. The relationship between the tensile-shear strength and the indentation depth has been investigated to evaluate the weldability and the optimum welding conditions. The welding current and the welding time have a greatly affect to the tensile-shear strength compared to the electrode force. It was found that the indentation depth has a relatively close relationship with the expulsion occurrence. The optimum welding conditions were proposed for the 4 lap spot welded joint.

• Journal of Welding and Joining
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• 제28권4호
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• pp.49-54
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• 2010

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds structures used stainless steel sheets are commonly fabricated by using the GMAW (gas metal arc welding). For fatigue design of GMA welded joints such as fillet and plug, ring type joint, it is important to obtain optimum design factor information on GMA welded joints. in this paper, analysis approach for fatigue test using design of experiment are evaluated optimum factor in GMA welded joint type and geometrical parameters of materials. Using these results, that factors applied to fundamental information for fatigue design.