• Title/Summary/Keyword: 굽힘붕괴

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船殼거더의 最終崩壞强度 解析法 및 簡易計算式에 관한 硏究 動向

  • 백점기
    • Bulletin of the Society of Naval Architects of Korea
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    • v.32 no.1
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    • pp.50-54
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    • 1995
  • 선박의 구조설계단계에서 최종붕괴강도를 설계기준으로 삼는 경우는 거의 없으나 최근에 각국 선급에서 최종붕괴강도를 의무적인 설계기준으로 삼기 위해 자체적인 해석법과 설계식을 제시 하고 규정화하는 작업을 진행시키고 있다. [12, 17, 31, 32]. 1994년 ISSC [1]에서도 토론된바와 같이 특히 새로운 구조방식을 가진 선박의 합리적인 구조설계를 위하여는 해상플렛폼의 구조설 계시와 마찬가지로 삼아야 할 것이다. 본고에서는 선각거더의 최종붕괴강도에 대한 해석법과 간이계산식에 관한 연구동향을 문헌조사를 통하여 분석하였다. 그 결과 순수굽힘모멘트가 작용 하는 문제의 경우 최종붕괴강도 해석법은 어느정도 확립되었다고 판단되지만 최종붕괴강도의 간이계산식은 아직도 정도 등의 면에서 개선의 여지가 남아 있다고 생각된다. 앞으로 순수 굽 힘모멘트뿐만아니라 조합하중을 받는 경우와 피로균열을 비롯한 초기구조손상을 가진 노후화된 선박에 대한 최종붕괴강도를 보다 정밀하게 해석하기 위한 해석법의 개발과 간이계산식의 도 출이 필요하다고 사료된다. 또한, 충돌, 좌초, 폭발 등에 기인된 선각거더의 붕괴강도 평가를 위한 해석법의 개발도 앞으로 남은 과제중의 하나이다.

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Center Pillar Design for High Bending Collapse Performance (굽힘 붕괴 성능 향상을 위한 센터 필라 설계)

  • Kang, Sungjong;Park, Myeongjae
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.4
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    • pp.128-134
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    • 2013
  • High bending collapse performance (maximum resistance force and mean resistance force) of body center pillar is an important design target for vehicle safety against side impact. In this study, effect of the upper section shape and the thickness of outer reinforcement on bending collapse performance was investigated for the center pillar of a large passenger car. First, through bending collapse analyses using simple models with uniform section, an optimized center pillar upper section was chosen. Next, bending collapse performance for various models of the actual center pillar with changing the thickness of outer reinforcement were analyzed. The finally designed model showed distinctive enhancement in bending collapse performance nearly without weight increase.

Large Deflection Analysis of a Plane Frame with Local Bending Collapse (국부적 굽힘붕괴를 수반하는 평면프레임의 대변형 해석)

  • 김천욱;원종진;강명훈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.8
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    • pp.1889-1900
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    • 1995
  • In this study, a large deflection analysis of a plane frame composed of a thin-walled tube in investigated. When bent, a thin-walled tube is usually controlled by local buckling and subsequent bending collapse of the section. So load resistance reaches the yield level in a thin-walled rectangular tube. This relationship can be divided into three regimes : elastic, post-buckling and crippling. In this paper, this relationship is theoretically presented to be capable of describing nonlinearities and a stiffness matrix is derived by introducing a compound beam-spring element. A numerical analysis uses a constant incremental energy method and the solution is obtained by modifying stiffness matrix at elastic/inelastic stage. This analytical results, load-deflection paths show a good agreement with the test results.

Test and Analysis for Axial and Bending Collapse Characteristics Evaluation of Aluminum Extruded Beams (알루미늄 압출재의 압괴 및 굽힘붕괴 특성규명을 위한 시험 및 해석)

  • 김범진;허승진;구정서;송달호
    • Journal of the Korean Society for Railway
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    • v.4 no.3
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    • pp.110-115
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    • 2001
  • Recently, many engineers actively participate in research and development w.r.t the weight reduction and the safety increase of vehicle body structure to meet the requirement of fuel economy and regulations. However, vehicle design concept related with weight reduction and safety increase is reduced to the design conflict problem. In the paper, the axial and bending collapse test of aluminum extruded beams are performed and the collapse characteristics are investigated. The analysis method to verify the fracture characteristics of aluminum extruded beam is presented and discussed.

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Effect of Bend Angle on the Collapse Behavior of Locally Wall Thinned Pipe Bends (감육 곡관의 붕괴거동에 미치는 곡관 굽힘각의 영향)

  • Na Man-Gyun;Kim Jin-Weon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.10 s.253
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    • pp.1269-1275
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    • 2006
  • The purpose of this study is to investigate the effect of bend angle on the collapse behavior of locally wall thinned pipe bends. For this purpose, the present study performed three-dimensional finite element analysis on the 30-, 60-, and 90-degree pipe bends with local wall thinning at the center of intrados, extrados, and crown, and evaluated the collapse moment for different thinning dimensions under closing- and opening-mode bending with a constant internal pressure. The results showed that, for intrados and extrados wall thinning, the reduction in the collapse moment due to local wall thinning became significant with decreasing bend angle of pipe bends. This effect of bend angle was enhanced with increasing thinning dimensions, and it was clearer fur opening-mode bending than for closing-mode bending. For crown wall thinning, however, the effect of bend angle was unclear and was less sensitive to the change of wall thinning shapes.

A Study on the Bending Collapse Analysis and Test of Al Extrusion Members (알루미늄 압출부재의 굽힘붕괴 해석 및 실험에 관한연구)

  • Kang, Shin-You;Seo, Sung-Soo
    • Journal of Industrial Technology
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    • v.17
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    • pp.213-218
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    • 1997
  • This study is concerned with characteristics of bending collapse of aluminum members with multi-cell section. Aluminum is light so it is compatible of being used for vehicle structures members. Bending collpase behaviors of aluminum members with multi-cell section are very complex and tension failure mode are occured in experiment. In this paper, the aluminum members are modeled to be able to represent the tension failure mode and, characteristics of bending collapse of aluminum members with multi-cell section by experimental method are compared with the results of PAM-CRASH.

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Roof Crush Analysis Technique Using Simple Model with Plastic Hinge Concepts (소성 힌지를 갖는 단순 보 모델을 이용한 루프 붕괴 해석 기술)

  • 강성종
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.6
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    • pp.216-222
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    • 1996
  • This paper presents a computational technique to predict roof crush resistance in early design stage of passenger car development. This technique use a simple F.E. model with nonlinear spring elements which represent plastic hinge behavior at weak areas. By assuming actual sections as equivalent simple sections, maximum bending moments which weak areas in major members can stand are theoretically calculated. Results from prediction of roof crush resistance are correlated well with test results.

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Foam Filling Effect on Bending Collapse Characteristics for Member Section Type (부재단면 형상에 따른 부재 굽힘붕괴 특성의 폼 충진 효과)

  • Lee, Il-Seok;Kang, Sung-Jong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.2
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    • pp.41-49
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    • 2007
  • More diversified and strengthened safety regulations require higher safety vehicle with less weight. The structural foam can play a role for restraining section distortion of main body members undergoing bending collapse at vehicle crash. In this study, using structural foam modeling technology, validated in previous work, the bending collapse characteristics were evaluated for two types of circular and actual vehicle body frame sections. With changing the foam filling method, outer panel thickness and section shape, load carrying capability and absorbed energy were observed. The results indicate valuable design strategy for effectively elevating bending collapse performance of body members with foam filled.

Bending Collapse Characteristics of Hat Section Beam Filled with Structural Foam (폼 충진 모자단면 빔의 굽힘붕괴 특성)

  • Lee, Il-Seok;Kang, Sung-Jong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.92-99
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    • 2006
  • Design capability for high safety vehicle with light weight is crucial to enhancing competitive power in vehicle market. The structural foam can contribute to restraining section distortion in body members undergoing bending collapse at vehicle crash. In this study, first, the validation of analysis model including structural foam model for simulating fracture behavior was discussed, and the bending collapse characteristics of five representative section types were analyzed and compared. Next, with changing the laminate foam shape, load carrying capability and absorbed energy were observed. The results suggests a design strategy of body members filled with laminate foam, leading to effectively elevating bending collapse characteristics with weight increase in the minimum.

A Study on the Specific Equation of Bending Collapse for Extruded Aluminum Members (알루미늄 압출부재의 굽힘붕괴 특성식 산출에 관한 연구)

  • Kang, Shin-Yoo;Jang, Hye-Jeong
    • Journal of Industrial Technology
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    • v.20 no.B
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    • pp.131-138
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    • 2000
  • In this paper, we would like to develop the bending collapse specific equation of aluminum members which are usually used in light-weight vehicle or electromobiles. The result of the developed equation are compared with that of test and finite element methods as the moment-rotational angle curves. Three types of aluminum members are tested with the pure bending collapse test rig. PAM-CRASH and ABAQUS program are used for finite element analysis. As the result the developed bending collapse governing equation is accurate in estimating the yield moment and the maximum moment. Especially, in the case of the local buckling and the delayed buckling, the developed equation is better effective than F.E.M.

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