• 한국자동차공학회논문집
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• 제23권5호
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• pp.524-536
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• 2015

The paper aims to design and verify tearing tube type energy absorption device applied in tram to ensure safety in case of collision accident. Energy capacity of tearing tube is determinated based on EN15227 and Standard Collision Scenarios Criterion in Detail in Republic of Korea. Tearing tube is designed based on theoretical model suggested by X.Huang et al. and assumption by T.Y. Reddy et al. Real scale collision tests are conducted to analyze the energy absorption characteristics and deformation mode. Bending of curl tips is absorbed collision energy when curl tips and tube body are contacted to each other from the tests and we suggest and include the formula on bending of curl tips in theoretical model.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.396-408
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• 2019

The tubes which are applied in jacket platforms as the supporting structure might be collided by supply vessels. Such kind of impact will lead to plastic deformation on tube members. As a result, the ultimate strength of tubes will decrease compared to that of intact ones. In order to make a decision on whether to repair or replace the members, it is crucial to know the residual strength of the tubes. After being damaged by lateral impact, the simply supported tubes will definitely loss a certain extent of load carrying capacity under uniform axial compression. Therefore, in this paper, the relationship between the residual ultimate strength of the damaged circular tube by collision and the energy dissipation due to lateral impact is investigated. The influences of several parameters, such as the length, diameter and thickness of the tube and the impact energy, on the reduction of ultimate strength are investigated. A series of numerical simulations are performed using nonlinear FEA software LS-DYNA. Based on simulation results, a non-dimensional parameter is introduced to represent the degree of damage of various size of tubes after collision impact. By applying this non-dimensional parameter, a simplified formula has been derived to describe the relationship between axial compressive residual ultimate and lateral impact energy and tube parameters. Finally, by comparing with the allowable compressive stress proposed in API rules (RP2A-WSD A P I, 2000), the critical damage of tube due to collision impact to be repaired is proposed.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.84-87
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• 2000

Square tubes used for vehicle structure components have an important role on keeping its stiffness and preserving occupant safety in vehicle collision and rollover in which it experience axial collapse, bending collapse or both. Bending collapse, which absorbs kinetic energy of the impact and retains a survival space for the occupant, is a dominant failure mode in oblique collision and rollover. Thus, in this paper, the bending collapse characteristics such as the maximum bending moment and energy absorption capacity of the square tube replaced by light-weight material were evaluated and presented. The bending test of cantilever tubes which were fabricated with aluminum, GFRP and aluminum/ GFRP hybrid by co-curing process was performed. Then the maximum bending moment and the energy absorption capacity from the moment-angle curve were evaluated. Based on the test results, it was found that aluminum/ GFRP hybrid tube can show better specific energy absorption capacity compared to the pure aluminum or GFRP tube and can convert unstable collapse mode which may occur in pure GFRP tube to stable collapse mode like a aluminum tube in which plastic hinge is developed.

• 연구논문집
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• 통권32호
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• pp.103-111
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• 2002

In this study, the crashworthiness of KHST has been evaluated by analysing a nonlinear spring/bar-damper-mass model of 1-dimensional collision dynamics. The numerical results show that KHST can easily absorb kinetic energy at lower impact force and acceleration in heavy collisions, when compared with KTX. Also, in a Light collision like a traint-to-train accident at lower speed under 8 kph, the carbody and components of KHST can be protected without any damage except the energy absorbing tube to be replaced easily. However, KTX may be much damaged in the light collision because there is no energy absorbing tube. In conclusion, the crashworthy performance of KHST has been much improved than that of KTX, although there are something to be improved for a better crashworthy performance

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.47-53
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• 2002

In this study, the crashworthiness of KHST is evaluated by analysing a nonlinear spring/bar-damper-mass model using 1 dimensional collision dynamics. The numerical results show that KHST can easily absorb kinetic energy at lower impact force and acceleration in heavy collisions, when compared with KTX. Also, in a light collision like a traint-to-train accident at speed under 8 kph, the carbody and components of KHST can be protected without any damage except a energy absorbing tube to be replaced easily. However, KTX may be much damaged in the light collision because there is no energy absorbing tube. In conclusion, the crashworthy performance of KHST has been much improved than that of KTX, although there remains something to be improved for a better performance.

• Bulletin of the Korean Chemical Society
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• 제18권12호
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• pp.1285-1288
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• 1997

The graphite tube nozzle has been developed for the generation of metastable He jet by which the nitrogen molecules initially excited in a jet with Engelking type nozzle have been further excited in a corona excited supersonic expansion. The excitation process of nitrogen molecules in the jet collision has been discussed in detail by observing the emission intensity from the vibronic emission spectra of nitrogen molecules and nitrogen molecular ions upon helium jet collision.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1483_1484
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• 2009

The electron collision cross sections for gases have been determined by electron beam and electron swarm method. Especially, measurements by electron swarm method is carried out by using the double shutter drift tube given by T.O.F. and Double shutter method.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.217-222
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• 2001

The best method to evaluate crashworthiness of a trainset as a whole is to analyse one dimensional dynamic model composed of nonlinear dampers, springs and bars, and masses. In this study, crashworthiness of KHST was evaluated by analysing a nonlinear spring/bar-damper-mass model. The numerical results show that the KHST can easily absorb kinetic energy at lower impact force and acceleration in a heavy collision, when compared with KTX. Also, the KHST can be protected from any damage in its carbody and components except the prepared energy absorbing tube in a light collision, like a traint-to-train accident at speed under 8 kph. However, the KTX can be much damaged in the a light collision because there is no energy absorbing tube.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.634-639
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• 2004

Under light collision accidents, the energy absorption strategy for the coupler and expansion tube of the TTX(Tilting Train Express) initial design is established in the paper. Also, 1st shearing bolts are designed. When the absorbed energy of the coupler reaches its maximum, the connecting bolts between the coupler and the car body are sheared off not to transmit the impact force to the car body structure. To absorb more energy after the lst shearing bolts work, a expansion tube is designed conceptually and installed at the rear part of the coupler. Using Hyper-Mesh and LS-DYNA, pre/post processing and light collision analyses are preformed, respectively.

• 대한기계학회논문집A
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• 제39권10호
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• pp.1053-1061
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• 2015

본 연구는 테어링 튜브에 플랫 다이를 설치하고 동하중이 가해졌을 때 에너지흡수용량 및 거동을 예측하기 위하여 수행하였다. 컬 끝과 튜브 본체가 접촉할 때 컬 끝의 굽힘이 발생함을 발견하고 식을 제안하였다. 그러나 컬 끝의 굽힘 하중과 에너지 소산율의 예측을 더욱 정확히 하기 위해 컬의 곡률반경의 변화와 튜브 두께의 감소에 주목할 필요가 있었다. X.Huang 등이 제안한 테어링 튜브 이론 모델에 컬의 평균 곡률반경, 감소하는 튜브 두께를 반영한 컬 끝의 굽힘 식을 추가하였고 충돌시험 결과를 통하여 검증하였다.