• 제목/요약/키워드: High impact

검색결과 7,190건 처리시간 0.039초

고속철도교량의 동적응답에 의한 충격계수 평가 (Evaluation of Impact Factor of High-Speed Railway Bridges from Dynamic Response under KTX Running)

  • 윤혜진;진원종;곽종원;황의승;김병석
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.1636-1640
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    • 2011
  • To consider dynamic magnification effect at the static design stage, impact factor is applied to design load. Current impact factor adopted EUROCODE without domestic verification through theoretical and experimental studies. This study evaluated impact factor of railway bridges from dynamic response under KTX running. Moving Average Method was applied to calculate impact factor. Investigation considering different type of bridges and tracks including velocity was conducted.

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유리/케블라 하이브리드 구조로 강화된 복합재료의 충격 거동 (Impact Properties of Glass/Kevlar Hybrid Composites)

  • 주기호;류한선;정관수;강태진
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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    • pp.191-194
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    • 2005
  • Impact properties of glass/Kevlar hybrid composites which have 3-D braided structures were studied. Results were compared to those of composites made of only glass fibers where the same epoxy resin were used as matrix. Absorbed impact energies evaluated through the combination of the data from the impact tester and high speed camera were compared to each other. In order to see the difference between the damaged area distribution CCD camera captures were performed.

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IMPACT ANALYSIS OF A WATER STORAGE TANK

  • Jhung, Myung-Jo;Jo, Jong-Chull;Jeong, Sang-Jin
    • Nuclear Engineering and Technology
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    • 제38권7호
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    • pp.681-688
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    • 2006
  • This study investigates the dynamic response characteristics of a structure impacted by a high speed projectile. The impact of a 300 kg projectile on a water storage tank is simulated by the general purpose computer codes ANSYS and LS-DYNA. Several methods to simulate the impact are considered and their results are compared. Based upon this, an alternative impact analysis method that is equivalent to an explicit dynamic analysis is proposed. The effect of fluid on the responses of the tank is also addressed.

A Study of the Factors that Impact Chinese Consumers' Purchasing Intent for High-Tech Products

  • Yi, Shan;Su, Shuai
    • Asian Journal of Business Environment
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    • 제4권1호
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    • pp.37-40
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    • 2014
  • Purpose - This objective of this study is to analyze the factors that impact Chinese consumers' purchasing intent for high-tech products. The study examines smart phones'features, Chinese personal consumer characteristics, and social influence. Research design, data, and methodology - The study employed survey data based on 200 questionnaires in principal Chinese cites between October and December 2011. SPSS 17.0 was employed to analyze the data used to test the hypotheses the analysis results confirmed some hypotheses proposed. Results - Hypothesis 1, Hypothesis 4, and Hypothesis 7 proposing that utilization, social image, and attractiveness, respectively, of smart phone elements influence the Chinese consumers' purchasing intent are supported. Conclusions - This study found the factors that impact purchasing intent for high-tech products among Chinese consumers, with some factors like social image, attractiveness, and utilization playing critical roles; however, hypotheses proposing factors such as ease of use, pleasantness, personal innovativeness, and compatibility were rejected. In future, more research focusing on the elements of smart phones is required.

고층건물에서의 연돌효과 시뮬레이션 (Simulation of the Stack Effect in High-Rise Builbings)

  • 양인호;여명석;조재훈;김광우
    • 설비공학논문집
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    • 제14권6호
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    • pp.456-467
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    • 2002
  • The objective of this study is to analyze and evaluate the impact of the stack effect in high-rise buildings for solving the various problems resulting from it. For the evaluation of the impact of the stack effect, computer program simulations based on the network model were performed for a typical high-rise office building. The results of the simulations show that the impact caused by the stack effect is mainly dependent on building envelope air-tightness and internal airflow resistance, so the problems due to the stack effect may be solved to some extent by installing vestibules around entrance doors and doors serving elevators, and by zoning the elevators.

동력분산형 고속전철의 충돌안전도 해석 및 평가기술 연구 (Study on the Crashworthiness Analysis and Evaluation of the High-Speed EMU)

  • 구정서;김거영;조현직
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.1213-1220
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    • 2008
  • In this study, the crashworthy design guidelines for the high speed EMU were derived and numerically evaluated. As for this high speed train, there are several different features from the KTX in that the conventional type bogies are adopted and the front end car (TC car) accommodates passengers. It is natural that the impact acceleration of the front end car should be controlled under the appropriate level stipulated at safety regulations for collision accidents. Also, car-to-car interfacing structures and devices should be deliberately designed to prevent overriding and telescoping mechanisms. As the first step for these design countermeasures, it was studied that how much impact energy should be absorbed at the energy absorbing zones and devices of each carbody to satisfy the impact acceleration regulations of the safety regulations. These results will be used as the crashworthy design guidelines for the high speed train in the next year research.

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SPH를 이용한 봉충돌 해석에서 구성방정식의 특성 (Characteristics of Constitutive Equations under Rod Impact Analysis by Smoothed Particle Hydrodynamics)

  • 김용환;김용석;이정민
    • 한국군사과학기술학회지
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    • 제6권3호
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    • pp.62-73
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    • 2003
  • The characteristics of constitutive equations, for hydrocodes, were Investigated by the comparison between the smoothed particle hydrodynamcis simulation and the experiment of rod impact test which resulted in a deformation history of impacting front where high strain and high strain rate dominate. The constitutive equations used in the simulation Is J-C(Johnson-Cook) model, Z-A(Zerilli-Armstrong) model, and S-C-G(Steinberg-Cochran-Guinan) model. The modification of Z-A model, based on the increased effect of strain-rate hardening, showed better correlation with expriment.

LCA를 이용한 고속철도 건설단계에서의 환경부하 특성에 관한 연구 (A Study on the Characteristics of Environmental Impact in Construction Sector of High-Speed Railway using LCA)

  • 이철;이재영;정우성;황용우
    • 한국철도학회논문집
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    • 제17권3호
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    • pp.178-185
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    • 2014
  • 본 연구에서는 국내 고속철도노선 전과정 중 건설단계에 대하여 각 분야별(토목, 궤도, 건축 및 전철전력/신호통신분야) 주요 건설자재 및 중장비 에너지 사용량을 토대로 전과정평가(Life Cycle Assessment, LCA) 방법론을 적용하여 주요 환경부하 특성을 분석하였다. 그 결과, 분야별 환경영향 기여도는 토목분야가 약 89%로 가장 높게 나타났으며, 궤도 7%, 건축 2%, 전철전력분야 2% 순으로 나타났다. 가장 기여도가 높은 토목분야의 경우, 주요 영향평가 범주는 지구온난화, 자원고갈, 광화학산화물생성으로 각각 54%, 25%, 8%로 나타났으며, 주요 영향인자는 레미콘과 시멘트인 것으로 분석되었다. 향후 철도 건설단계에서의 전과정평가 적용은 정량적인 환경부하 산정을 통해 효율적인 저감방법을 도입할 수 있다.

족부보장구(A.F.O.) 판스프링용 Glass/Epoxy와 Aramid/Epoxy의 충격속도 변화에 따른 손상 거동 (The Damage Behavior of Glass/Epoxy and Aramid/Epoxy in Leaf Spring of Ankle Foot Orthosis (A.F.O) due to the Various Impact Velocities)

  • 송삼홍;오동준;정훈희;김철웅
    • 대한기계학회논문집A
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    • 제28권10호
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    • pp.1526-1533
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    • 2004
  • The needs of walking assistant device such as the Ankle Foot Orthosis (A.F.O) are getting greater than before. However, most of the A.F.O are generally imported rather than domestic manufacturing. The major reason of high import reliability is the rack of impact properties of domestic commercial products. Therefore, this research is going to focus on the evaluation of impact properties of the A.F.O which has the high import reliability. Unfortunately, these kinds of researches are not performed sufficiently. This research is going to evaluate impact energy behavior in composite materials such as the glass/epoxy (S-glass, [0/90]sub 2S/) and the aramid/epoxy (Kevlar-29, woven type, 8 ply) of ankle foot orthosis. The approach methods were as follows. 1) The history of impact load and impact energy due to the various velocities. 2) Relationship between the deflection and damage shape according to the impact velocities. 3) The behavior of absorbed energy and residual strength rate due to the various impact velocities.