• Title/Summary/Keyword: Mean Crush Load

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The energy absorption behavior of square tube by F.E.M (유한요소법에 의한 사각형 튜브의 충돌에너지 흡수거동 II)

  • 강대민;윤명균;황종관
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.04a
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    • pp.181-188
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    • 2000
  • This paper describes the energy absorption of a square tube under axi compression by using the finite element method. The overall deformations and lo buckling modes of tube was discussed by "plastic hinge concep Force-displacement function was plotted to show various state that depended or time. Also, mean crush load was expressed as a type of section geometry a material property using dimensional analysis. To verify the energy absorption and the effects of dimensions, The standards Wt used as related density and specific energy, mean crushing load and the resL were discussed by the relation between crush load and deformation, the relati between related density and specific energy, the relation between crush load a mean crush load, the relation between mean crush load and specific energy.ergy.

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The Dynamic Mean Crush Load of Thin-walled Square Tubes (박판 정4각튜브의 동적 평균압괴하중)

  • 김천욱;한병기;원종진
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.5
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    • pp.119-127
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    • 1998
  • Assuming that the static loaded square tube and the dynamic loaded one have no difference in their characteristics of the crush distance, the theoretical mean dynamic crush load was calculated with respect to the impact speed considering the strain rate sensitivity of the material. The ratio of dynamic to static mean crush load was predicted with previous results. The theoretical analysis was compared with the experimental results of aluminum square tubes axially loaded dynamically.

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The Energy Absorption Characteristics of Thin-walled Rectangular Tubes (박판 사각튜브의 에너지 흡수 특성)

  • 김천욱;한병기;원종진;임채홍
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.3
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    • pp.83-91
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    • 1996
  • This paper investigates the energy absorption characteristics of thin-walled rectangular tubes. In the compact mode, the crushing process of a thin-walled tube is analyzed into 3 parts by the ratio of outward to inward fold length. The mean crush load and the half-wave folding length are determined by using minimum energy principle. The effective crush distance can be determined when half-wave folding length is known, and the number of folds is derived when crush distance is given. Thus when the crush distance is given, energy absorption capacity can be estimated with mean crush load and number of folds. And the theoretical value is proven experimentally.

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A Study on the energy absorption characteristics of GFRP circular tubes fabricated by the filament winding method (필라멘트 와인딩 공법 GFRP 원형 튜브의 에너지 흡수특성에 관한 연구)

  • Kim, Geo-Young;Koo, Jeong-Seo
    • Composites Research
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    • v.22 no.4
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    • pp.1-12
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    • 2009
  • In this paper, quasi-static crushing tests of composite circular tubes under axial compression load are conducted to investigate the energy absorption characteristics. Circular tubes used for this experiment are glass/epoxy (GFRP) composite tubes which are fabricated by the filament winding method. One edge of the composite tube is chamfered to reduce the initial peak load and to prevent catastrophic failure during crushing process. Energy absorption characteristics vary significantly according to the constituent materials, fabrication conditions, tube geometry and test condition. In tube geometry, according as inner diameter increase, unstable crush mode is caused by local buckling of delamination, but control of the fiber orientation should help composite tubes get stable crush mode.

Axial Crush and Energy Absorption Characteristics of Aluminum/GFRP Hybird Square Tubes (알루미늄/GFRP 혼성 사각튜브의 정적 압축 붕괴 및 에너지 흡수 특성)

  • 김구현;이정주;신금철
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.6
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    • pp.208-219
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    • 2000
  • In this study, static axial crush tests were performed with the new aluminum/GFRP hybrid tube. Glass/Epoxy prepregs were wrapped around an aluminum tube and co-cured. The failure of the hybrid tube was stable and progressive without trigger mechanism, and specific energy absorption was increased to the maximum of 33% in comparison with the aluminum tube. Effective energy absorption is possible for an inner aluminum tube because a wrapped composite tube constrains the deflection of an aluminum tube. The failure of a hybrid composite tube was stable without trigger mechanism because the inner aluminum tube could play the role of the crack initiator and controller. Mean crushing load could be calculated by modifying the plastic hinge collapse model for hybrid materials. The predicted results by this analytical model showed good agreement with the experimental results. It can be said that Aluminum/Glass-Epoxy hybrid tube is suitable for the vehicle front structure because this hybrid tube shows effective energy absorption, easy production, and simple application capability for RTM process.

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Derivation of the Standard Design Guidelines for Crashworthiness of the High-Speed EMU (동력분산형 고속전철의 충돌안전도 설계 가이드라인 도출)

  • Kim, Geo-Young;Cho, Hyun-Jik;Koo, Jeong-Seo
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.772-779
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    • 2008
  • Through this study, standard design guidelines for the high speed EMU have been derived to meet the crashworthiness requirements of the Korean rollingstock safety regulation. The crashworthiness regulation requires some performance requirements for two heavy collision accident scenarios; a train-to-train collision at the relative speed of 36 kph, and a collision against a standard deformable obstacle of 15 ton at 110 kph. The complete train set will be composed of 2TC-6M with 13 ton axle load, different from KTX with the power car of 17 ton axle load. Using theoretical and numerical analyses, some crashworthy design guidelines were derived in terms of mean crush forces and energy absorptions for main crushable structures and devices. The derived design guidelines were evaluated and improved using one dimensional spring-mass dynamic simulations. It is shown from the simulation results that the suggested design guidelines can easily satisfy the domestic crashworthiness requirements.

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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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Scale Modeling Technique for the Crash Analysis of Railway Vehicle Structure (철도차량 충돌 해석을 위한 축소모델링 기법 연구)

  • 김범진;허승진
    • Journal of the Korean Society for Railway
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    • v.5 no.4
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    • pp.231-236
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    • 2002
  • Todays, crash safety requirements of the railway vehicle structures become important design criterion according to the increased driving speed and the lightweight construction. Although the crash analysis using computer simulation can be effectively applied to predict the crash performance of the railway vehicles in the early design stage, the optimized design w.r.t the crash safety could be realized by the crash tests with actual prototype vehicles. However, it is very expensive and time-consuming task to perform the crash test of the railway vehicles. As a measure to cope with the problem, in this paper, the scale modeling technique is suggested and experimentally verified to predict the impact energy absorption characteristics of full scale model of aluminum extrusions sub-structures and the high-speed railway vehicle structure.

A Derivation of the Standard Design Guideline for Crashworthiness of High Speed Train with Power Cars (동력집중식 고속열차의 충돌안전도 표준설계 가이드라인 도출)

  • Kim, Geo-Young;Cho, Hyun-Jik;Koo, Jeong-Seo;Kwon, Tae-Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.6
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    • pp.157-167
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    • 2008
  • Through this study, the standard design guidelines for high speed train with power cars have been derived to meet the crashworthiness requirements of the Korean rollingstock safety regulation. The crashworthiness regulation requires some performance requirements for two heavy collision accident scenarios; a train-to-train collision at the relative speed of 36 kph, and a collision against a standard deformable obstacle of 15 ton at 110 kph. A standard high speed train composition was defined as 2PC-2ET-6T with 17ton axle load, similar to KTX-2 for the Honam express line. Using theoretical and numerical analyses, some crashworthy design guidelines were derived in terms of mean crush forces and energy absorptions for major crushable components. The derived design guidelines were evaluated and improved using one dimensional spring-mass dynamic simulation. It is shown from the simulation results that the suggested design guidelines can easily satisfy the domestic crashworthiness requirements.

A Study on Conceptual Design for Crashworthiness of the Next Generation High-speed EMU (동력분산형 차세대고속전철의 충돌안전도 개념설계 연구)

  • Kim, Geo-Young;Cho, Hyun-Jik;Koo, Jeong-Seo
    • Journal of the Korean Society for Railway
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    • v.11 no.3
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    • pp.300-310
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    • 2008
  • Through this study, a conceptual design for the next generation high-speed EMU has been derived to meet the crash worthiness requirements of the Korean rollingstock safety regulation. The crashworthiness regulations require some performance requirements for two heavy collision accident scenarios; a train-to-train collision at the relative speed of 36 km/h, and a collision against a standard deformable obstacle of 15 ton at 110km/h. The complete train set will be composed of 2TC-6M with 13 ton axle load, which is different from KTX with the power car of 17 ton axle load. Using theoretical and numerical analyses, a crashworthy conceptual design was derived in terms of mean crush forces and energy absorptions for principal crushable structures and devices. The derived conceptual design was evaluated and improved using one dimensional dynamic simulations for the bar-spring-damper-mass model. It is shown from the simulation results that the suggested conceptual design can easily satisfy domestic crashworthiness requirements.