• Title/Summary/Keyword: 굽힘붕괴

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Bending Performances and Collapse Mechanisms of Light-weight Aluminum-GERP Hybrid Square Tube Beams (경량화 알루미늄-GFRP 혼성 사각관 보의 굽힘성능 및 붕괴 메커니즘)

  • Lee, Sung-Hyuk;Kim, Hyung-Jin;Chang, Young-Wook;Choi, Nak-Sam
    • Composites Research
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    • v.20 no.3
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    • pp.8-16
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    • 2007
  • Bending collapse of light-weight square tubes used for vehicle structure components is a dominant failure mode in oblique collision and rollover of vehicles. In this paper bending performances of aluminum-GFRP hybrid tube beams were evaluated in relation with bending deformation behavior and energy absorption characteristics. Aluminum/GFRP hybrid tube beams fabricated by inserting adhesive film between prepreg and metal layer were used in the bending test. Failure mechanisms of hybrid tubes under a bending load were experimentally investigated to analyze the bending performance as a function of ply orientation and composite layer thickness. Ultimate bending moments and energy absorption capacity of hybrid tube beams were obtained from the measured load-displacement corves. It was found that aluminum/GFRP hybrid tubes could be converted to rather stable collapse mode showing excellent energy absorption capacity in comparison to the pure aluminum tube beams. In particular, the hybrid tube beam with $[0^{\circ}/90^{\circ}]s$ composite layer showed a large improvement by about 78% in energy absorption capacity and by 29% in specific energy absorption.

Development of a Pure Bending Test Machine and Bending Collapse Characteristics of Rectangular Tubes (순수굽힘 시험기개발 및 사각관부재의 굽힘붕괴특성 연구)

  • 강신유;장인배;김헌영
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.1
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    • pp.222-233
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    • 1998
  • A 4-point pure bending res machine is developed the evaluate the pure vending moment-rotation properties of the thin-walled tubes without imposing shear and tensile forces. The moment-rotation properties of the thin-walled tubes are measured up to and beyond collapse with the pure bending test machine. The test results are compared with those of finite element analyses and existing analytical solution.

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A Study on the Evaluation Method for Bending Collapse Behavior of an Aluminum Square Tube (굽힘붕괴를 수반하는 알루미늄 사각관의 시험법에 관한 연구)

  • 이성혁;최낙삼
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.10a
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    • pp.123-126
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    • 2002
  • To evaluate the bending collapse behavior of an aluminum square tube, a finite element simulation for the four-point bending test was suggested. Local buckling deformation near the center of an aluminum tube specimen was induced which has been partly inserted by two steel bars. Simulation results showed good agreements with those of experiment.

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A Study on the Bending Collapse at the Open Cross-Section Members with Experiment and Analysis (열린 단면 부재의 굽힘 붕괴 실험 및 해석에 관한 연구)

  • 이승철;강신유
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.4
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    • pp.132-139
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    • 2004
  • The open section members have been used as the members of vehicle such as automotives, airplanes and trains. When vehicles are crashed, these members have absorption of the energy and it is necessary for retainment of the survival space, and as the result, the prediction for the displacement of members in this case of the crash of vehicles is very important. The displacements of members in this case of the crash of automotives show combined aspect of both axial collapse and bending collapse. In the rollover accident when bending collapse happen, the collapse of each members is progressed by the plastic hinge which made from bending moment, and therefore the research for the behavior of members under bending moment after collapse is necessary to determine the internal energy which the members can absorb and the deformed shapes of the members on the step of design. In this paper, the characteristics of bending collapse at the members of the open cross-section were studied with experiment and numerical analysis. We made a comparative studied of the result of the experiment, and changed the axis according to the parallel-axis theorem.

An Experimental Study on Deep Collapse of Steel Tubes under Pure Bending (순수 굽힘 시험기를 이용한 연강 사각관의 굽힘 붕괴에 관한 실험적 연구)

  • KiM, C.S.;Chung, T.E.;Kang, S.Y.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.9
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    • pp.37-44
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    • 1997
  • In this paper the bending collapse characteristics of square and rectangular steel tubes were studied with the pure bending test machine which apply pure bending moment without imposing shear and tensile forces. Under pure bending moment, delayed buckling modes occur and depend on test length and shape of section. For delayed mode, the endrgy of bending moment is absorbed by strain hardening energy. The pre- dictions of maximum moment and moment-rotation angle curve from those concepts are in good agreement with experimental observations.

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Research trends on the automobile crush (자동차 충돌특성 연구동향)

  • 김천욱;한병기;원종진;임채홍
    • Journal of the korean Society of Automotive Engineers
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    • v.18 no.4
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    • pp.1-17
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    • 1996
  • 자동차의 안전에 대한 연구는 객실의 변형제한과 승객의 감속도 축소를 위한 여러가지 구조부재의 에너지 흡수능력 및 흡수 메카니즘을 연구하는데 초점이 맞추어져 왔다. 그 이유는 충돌사고시에 인명을 보호하기 위해서는 차제변형에 의한 물리적 접촉의 회피 뿐 아니라 충돌에너지를 적절히 흡수조절하여 충돌력을 감소시키도록 구조부재를 설계함으로써 충돌안전성이 확보되기 때문이다. 충돌에너지 흡수 특성은 구조부재의 단면 형상과 재질에 따라 달라지며 압괴모드도 구분되어진다. 즉, 복합재료의 압축붕괴특성은 금속이나 플라스틱 재질과는 다르다. 일반적으로 복합재는 재질의 파손으로 에너지가 흡수되지만 금속재는 소성변형으로 에너지를 흡수한다. 이때의 붕괴양상은 작용하중에 따라 축방향 붕괴, 굽힘붕괴, 측면붕괴의 경우는 정규압괴모드(compact mode) 및 불규칙압괴모드(noncompact mode)로 나뉘고, 원통쉘의 경우는 축대칭모드 및 다이아몬드형 모드 등으로 나뉠수 있다. 원형 및 사각 튜브는 광범위한 형상비와 후폭비를 가지도록 제작할 수 있으며 산업전반에 걸쳐 널리 쓰이므로 충돌특성 연구의 대상으로 많은 연구들이 진행되어 왔다. 또한, 충돌특성의 해석을 위한 이론적 모델이 제시되었으며 계속적인 보완이 이루어져 오고 있다.

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Crush Characteristics of Thin-walled Rectangular Tube (박판사각튜브의 압괴 특성)

  • 이종선
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.10a
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    • pp.261-266
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    • 1998
  • In this study, crush characteristics of thin-walled rectangular tube is investigated. The stiffness of the element is obtained from analytical moment-rotation relationship and approximated load-deflection relationship of thin-walled rectangular tube. A computer program is developed for the large deformation analysis of frame. An incremental displacement method is used in the program and at each incremental stage, the stiffness matrix of the total structure is checked with the state each element for bending and compression.

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A Study on the Local Buckling Collapse Behavior of an Aluminum Square Tube Beam under a Bending Load (굽힘하중을 받는 알루미늄 사각관 보의 국부적 좌굴붕괴 거동에 관한 연구)

  • Lee, Sung-Hyuk;Choi, Nak-Sam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.12
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    • pp.2011-2018
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    • 2003
  • To analyze the bending collapse behavior of an aluminum square tube beam under a bending load, a finite element simulation for the four-point bending test has been performed. Using an aluminum tube beam specimen partly inserted with two steel bars, the local buckling deformation near the center of the tube beam was induced. The maximum bending load and the bending collapse behavior obtained from the numerical simulation were in good agreement with experimental results. Using a combination of the four-point bending test and its finite element simulation, analysis of the local buckling and the accompanied bending collapse behavior of aluminum tube beam could be quantitative accomplished.

Collapse Behavior of Vehicle Structures (처체구조물의 붕괴거동)

  • 김천욱;한병기;원종진;이종선
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.3
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    • pp.54-62
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    • 1998
  • In this study, collapse behavior of frame composed of thin-walled rectangular tube is investigated. Considering the collapse of frame, the bending and compression members undergo large deformation. The stiffness of the compound element is obtained from analytical moment-rotation relationship and approximated load-deflection relationsh- ip of thin-walled rectangular tube. A computer program is developed for the large deformation analysis of frame. An incremental displacement method is used in the program and at each incremental stage, the stiffness matrix of the total structure is checked with the state of each element for bending and compression.

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