• Title, Summary, Keyword: 충돌변형량

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Body structure for the front impact of One-Box car (One-Box Car 충돌 대비 차체 구조)

  • 박규환
    • Journal of the korean Society of Automotive Engineers
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    • v.13 no.3
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    • pp.19-24
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    • 1991
  • 본 고에서는 자동차 안전대책중에서 One-box car의 전면충돌 안전대책에 대하여 개략적으로 소개하고자 한다. 1. 충돌기본식 1/2M$V^{2}$=F.S에서 에너지 흡수율이 frame의 변형 평균 하중과 차체 변형량에 좌우된다. 2. frame 형상은 굽힘형보다 압축형이 동일한 변형구간에서 월등한 충돌에너지를 흡수한다. 3. 압축형 frame의 에너지 흡수효과는 main-frame의 버팀강도가 e.a-frame의 변형 하중보다 강해야만 그 효과를 충분히 얻을 수 있다.

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Collision Behaviors Analysis of Sandwich Concrete Panel for Outer Shell of LNG Tank (LNG외조를 구성하는 샌드위치 콘크리트 패널의 충돌거동해석)

  • Lee, Gye Hee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.6
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    • pp.485-493
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    • 2017
  • In this study, the collision analysis of SCP(Sandwich Concrete Panel) composing the outer tank of LNG storage was performed and its collision behavior was analyzed. For the same collision energy value proposed in BS7777 code, the collision conditions are composed by using two types of missiles and various collision speeds. Nonlinear dynamic analysis models were constructed to perform numerical analysis on the various collision conditions. Also, the collision behavior was analyzed assuming that the second collision with the same collision energy occurs at the same point after the first collision. As a result of the analysis, it was found that with smaller missile and low collision speed had caused larger deformation. The collision energy dissipated in ratio of about 6: 4 in the outer steel plate and the inner filling concrete. In the results of double collision analysis, the final collisional deformation was dominated by the size of the second missile, and the amount of deformation due to the second collision was smaller than that of the first collision because of the membrane behavior of the steel plates. In the offset double collision cases, the largest deformation occurs at the secondary collision point regardless of the offset distance.

Collision alleviation algorithm with Binomial Backoff retransmission method in CSMA/CA of Wireless VHF Communication (무선 VHF통신의 CSMA/CA에서 Binomial Backoff 재전송 방식을 이용한 충돌 완화 알고리즘)

  • 박용태;김용중;이동준;박효달
    • Proceedings of the IEEK Conference
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    • pp.235-238
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    • 2003
  • 본 논문에선 Binomial확률을 이용한 재전송 슬롯 선택방식과 충돌해결과정의 수정을 통하여 CSMA/CA 프로토콜을 항공용 VHF통신에 적합하게 변형시켰다. 일반적으로 CSMA/CA 프로세스는 경쟁 서비스에서 충돌이 일어났을 때 재전송 지연시간만큼 기다리게 되고 경쟁윈도우의 크기가 두 배로 커진다. 이로 인해 부하가 증가하면 지연시간이 커지고 처리량이 감소하며 이를 해결하기 위해 본 논문에선 충돌 플래그를 이용하여 본래의 CW의 크기 변화 과정을 변형시켰으며, CSMA/CA 전체 상태 천이 과정에서 충돌 시의 과정을 좀더 적게 거치도록 하였다. 시뮬레이션을 수행한 결과 부하가 증가하여도 처리량 및 지연 시간에 좋은 특성을 나타내었으며 제안된 프로토콜은 항공용 VHF 통신에 적합함을 확인하였다.

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Collision Configurations Reconstruction Using Deformation Shape and Deformation Severity of Car Body (차체의 변형상과 변형정도에 의한 자동차 충돌상황의 재구성)

  • 장인식;채덕병
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.1
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    • pp.171-180
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    • 2001
  • Collision accident reconstruction algorithm are developed based on the deformation shape and severity of a car body. At first, the body stiffness equation representing the force-deformation relationship is derived using finite element analysis for head on collision of two cars. The database of deformation shapes and energies is constructed for five different collision configurations; each configuration contains three velocity conditions. Deformation shapes are obtained using a curve fitting method and result in cubic polynomials. Deformation energies are calculated using a stiffness equation and deformation data. Three algorithms are developed to reconstruct collision configuration compared with constructed database. The developed algorithms show reasonably good performance to find collisions conditions for some test problems.

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A Study on Side Impact from Car-to-Car using Finite Element Analysis (유한요소해석을 이용한 차대차 측면충돌에 대한 연구)

  • Han, Yuong-Kyu;Baek, Se-Ryong;Yoon, Jun-Kyu;Lim, Jong-Han
    • The Journal of The Institute of Internet, Broadcasting and Communication
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    • v.15 no.3
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    • pp.201-209
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    • 2015
  • The deformed degree of car body varies largely with the collision part from side collision of car-to-car. In case of deformation of car body caused by collision, the movement is different as speed energy changes to strain energy. Generally, in the analysis of traffic accident, the movement of car after the collision is analyzed by law of conservation of motion and the error of energy absorption rate along the deformation of car body can be calibrated by inputting coefficient of restitution, but it is current situation that coefficient of restitution applied by referring to the research results of forward collision and backward collision because the research results of side collision is rare. Vehicle model of finite element method applied by structure of car body and materials of each component was analyzed by explicit finite element method, and coefficient of restitution and collision detection time along contact part of side collision was drawn by analyzing the results. Analysis result acquired through the law of conservation momentum by applying finally-computed coefficient of restitution and crash detection time compared to collision result of actual vehicle. As a result, the reliability of analysis was higher than the existing analysis method were acquired when applying the drawn initial input value that used finite element method analysis model.

Automobile Collision Reconstruction Using Post-Impact Velocities and Crush Profile (충돌 후 속도와 충돌 변형으로부터 자동차 충돌 재구성)

  • 한인환
    • Journal of Korean Society of Transportation
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    • v.18 no.4
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    • pp.107-115
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    • 2000
  • We suggest a method which solves the planar, two vehicle collision reconstruction problem. The method based on the Principle of impulse and momentum determines the pre-impact velocity components from Post-impact velocity components, vehicle Physical data and collision geometry. A novel feature is that although the impact coefficients such as the restitution coefficient and the impulse ratio are unknown, the method can estimate automatically the coefficients and calculate the pre-impact velocity components. This reverse calculation is important for vehicle accident reconstruction, since the pre-impact velocities are unknown and Post-impact Phase is the starting Point in a usual collision analysis. However. an inverse solution is not always Possible with the analytical rigid-body impact model. Mathematically, one does not exist under the common velocity condition. On the other hand, our method has a capability of reverse calculation under the condition if the absorbed energy during the collision process can be estimated using the crush profile. To validate the developed collision reconstruction a1gorithm, we use car-to-car collision test results. The analysis and experimental results agree well in the impact coefficients and the Pre-impact velocity components.

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GPU-Based Parallel Collision Detection for Deformable Objects (변형 물체를 위한 GPU 기반 병렬 충돌 감지)

  • Sung, Nak-Jun;Kim, Min Sang;Hong, Min;Choi, Yoo-Joo
    • KIPS Transactions on Software and Data Engineering
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    • v.7 no.1
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    • pp.25-32
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    • 2018
  • Due to heavy computational cost, deformable object simulation requires more effective collision detection method than rigid body simulation. However, when the CPU-based collision detection algorithm is purely applied to the GPU environment, the collision detection algorithm and the data structure optimized for the GPU environment are essential because the performance of the GPU can not be used properly. Therefore, we propose a GPU-based parallel collision detection algorithm for mass-spring system which is widely used for deformable object representation in this paper. The proposed method uses a parallel algorithm and data structure to reduce collision detection cost through GPU-based curling algorithm using AABB-Octree structure. In this paper, we prove the effectiveness of the proposed method by comparing the intersection test of all triangle pairs in parallel. The results of experimental tests show that the proposed method improves the performance by about 24% on average. Therefore, it is expected that the proposed method can improve the performance of real-time simulation for deformable objects.

Development of an impact test device for Light-weight Automotive Reinforcements (자동차 보강재 경량화을 위한 충격 실험장치 개발)

  • Kim, Ick-Tae;Kang, Hyung-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.10
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    • pp.5963-5967
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    • 2014
  • Reducing the impact of collisions of cars is a major issue for reducing the injury and death of passengers. According to the statistical data of the Road Traffic Authority, the deaths from side collision accidents caused by the collision of passenger cars is greater than the deaths from head-on collision accidents. To accommodate this, vehicle designers have added a reinforcing material called the impact frame and impact beam on the inside of the door. Many experiments are needed to develop the door impact beam. These reinforcements to develop a collision experiment is essential. Collision experiments are costly and time consuming. This study used a drop Impactor to obtain the impulse and a strain experimental device was developed for this purpose. The economic costs were reduced and the ideal experiment device configuration was determined. A comparison of the experimental results with numerical value analysis revealed $3.5{\tiimes}10-3sec$ strain ranging from $3.49{\tiimes}10-3$ to $3.99{\tiimes}10-3$.

Study on Behavior Characteristics of a Pile-Type Vessel Collision Protective Structure (파일형 선박 충돌방호공의 거동특성 연구)

  • Lee, Gye-Hee;Lee, Jeong-Woo
    • Journal of the Society of Disaster Information
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    • v.7 no.1
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    • pp.75-85
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    • 2011
  • In this study, the behavior were analyzed for the bow collision event. The model of protective Structure was consist of slab, RCP and non-linear soil spring. The ship was modeled by bow and midship. The bow model was composed by elastic-plastic shell elements, and the midship was composed by elastic solid element. According to the weight of the ship's change from DWT 10000 until DWT 25000 increments 5000. The head-on collision was assumed, its speed was 5knot. Analysis was carried out ABAQUS/Explicit. As the result, increasing the weight of the ship deformability in athletes and to increase the amount of energy dissipated by the plastic could be confirmed.

Simulation Analysis on the Impact of Racing Car with Space Frame (스페이스 프레임을 가진 경주용 차량의 충돌에 관한 시뮬레이션 해석)

  • Cho, Jae-Ung;Bang, Seung-Ok;Kim, Key-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.7
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    • pp.2341-2348
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    • 2010
  • In this paper, strain and stress on space frame are analyzed at racing car under crash loads. As the deformation is reduced to a minimum during crash and the vulnerable parts are grasped, the safety of driver is ensured. The vehicle frame is modelled with truss structure by inputting the material property of carbon steel on finite element analysis. The increase of impulse momentum is due to speed change at frontal collision. This influence effected on vehicle frame is also analyzed by ANSYS program. The deformation of the frame is studied by applying the crash loads at front, side and rear directions. Though the influence on the seat of driver is small at frontal and rear crash, the deformation due to impact is progressed into this seat. The safety of frame is enhanced by making up for these weak deformations and these results of simulation analysis can be applied to the production of the actual vehicle frame.