• Title/Summary/Keyword: Impact speed

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A Study on the Bow Collapse of High-Speed Passenger Craft in Collision with Bridge Pier (고속 여객선의 교각 충돌에 대한 연구)

  • 신영식;박명규
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.5 no.1
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    • pp.1-8
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    • 1999
  • During the last 10 years, the various type of high speed craft have been greatly developed, and since around of 1990 the large size of high speed passenger and/or cargo vessels are also introduced and took into the service in the various routes over the world. In a marine traffic way some bridge need to build across a rivers, cannals or a waterways. This one will be an obstruction and potential risk of collision in the way of high speed craft. Accordingly some of collision accident have been reported, which were caused by a lost control, wind and hydrodynamic forces, fog or human errors. In this paper a high speed craft having 40 m length is assumed to be collided with a circular type of bridge piers at right angle. The mode of deformation, penetration depth of collapse, impact forces, reduction of speed, loss of kinetic energy, and influence of scantlings, etc. have been calculated in each speed with a time variation to find a maximum values within a limit, and are graphically presented.

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Measuring The Speed of The Golf Ball after Impact (임팩트 후 골프공의 속도 측정)

  • Shin, Seong-Yoon;Lee, Hyun-Chang;Kim, Hee-Ae;Rhee, Yang-Won
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.129-131
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    • 2013
  • In this paper, a golf club head strikes the golf ball moves at a constant speed. Then the head of a golf club moves at a constant speed in the same direction. Then calculate the speed of the golf ball to hit a golf ball flying. It calculate the speed of the golf ball is different for each speed before hitting the golf ball.

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Highway Design Speed and Its Impacts: Some Evidence in South Korea

  • Choi, Jai-Sung;Tay, Richard;Kim, Sang-Youp
    • Transportation Technology and Policy
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    • v.6 no.1
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    • pp.155-170
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    • 2009
  • In an effort to increase the operational efficiency of highways, South Korea has been increasing its design speed recently. However, the use of higher design speed will also increase construction costs. Moreover, increasing the design speed is expected to have an impact on safety. Hence, there is a strong need to demonstrate that the benefits outweigh the cost of having a higher design speed. This study surveyed a sample of design engineers to determine their awareness of the consequences of increasing design speed and their assessment of the right design speed for an actual rural arterial. In addition to the survey, a case study of three recently upgraded highways was conducted to determine the changes in traffic volumes, speeds, travel times, and safety.

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Assessment of Long-Term Effectiveness of Speed Monitoring Displays on Speed Variation (어린이보호구역에 과속경보시스템 적용에 따른 장기적 속도변화 평가)

  • Lee, Sang-Soo
    • Journal of the Korean Society of Safety
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    • v.21 no.3 s.75
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    • pp.107-113
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    • 2006
  • Speeding is one of major causes of frequent and severe traffic accidents in school zones. In this paper, the long-term effectiveness of speed monitoring displays (SMD) on speed variability was investigated through a field study in a school zone environment. The performance difference was discussed with several dependent variables including average speed, 85th percentile speed, and distribution of speed. Study results showed that the speed of vehicles began to reduce where the driver recognized the presence of an SMD, and about 12.4 percent (5.8km/h) of average speed was reduced at the SMD location. This speed reduction was observed throughout the day regardless of time of day. Statistical tests showed that the speed difference was statistically significant. In addition, analysis results of speed distribution showed that the number of speeding vehicle was greatly reduced after the SMD was installed, and 85th percentile speed also decreased from 54.3km1h to 45.0km/h. Therefore, it was concluded that the application of SMD produced a positive impact on the driver's behavior for a long period of times.

A Study on Numerical Analysis of Impact Behavior by the Modified GPA Method (수정 GPA법을 이용한 층돌거동의 수치해석에 대한 연구)

  • 김용환;김용석
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.1
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    • pp.189-196
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    • 2004
  • A modified generalized particle algorithm, MGPA, was suggested to improve the calculation efficiency of standard SPH Method in numerical analysis of high speed impact behavior. MGPA had a new weight function to reduce computation time. The efficiency of this method was proven through calculation for the sample problems of one dimensional rod impact problem and two dimensional plate impact problem. The MGPA method reduced the calculation error and stress oscillation near the boundaries. The validity of this approach was shown by the comparison with ABAQUS results in two dimensional plate impact problem.

A safety assessment by Risk Analysis Method on wheelchair occupant in side impact (측방충돌시 휠체어 탑승자의 위험도 분석에 의한 안전성평가)

  • 김성민;김성재;강태건;전병호;김경훈;문무성;홍정화
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.10a
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    • pp.16-16
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    • 2003
  • In this study, for a safety assessment of wheelchair occupant in side impact, we used a dynamic sled impact test results. The test was carried out total 6 times and impact speed was 13g±0.43/28km/h±0.95, By using EURO SID-1 dummy, head performance criteria(HPC), abdominal peak force, etc. were measured. We evaluated wheelchair occupant safety by motion criteria(MC) which was measured by head, trunk and side deformation change of wheelchair and Head & Neck injury criteria(HNI) measured by using head and neck deformation angle and time relation. When we assumed that the maximum injury value in side impact was 100%, the results of motion criteria(MC) of wheelchair occupant were max 80.3, mim 32.3 and average 60.3%, Head & Neck injury criteria(HNI) value were max 118.4, min 14.5 and average 59.7%.

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Impact Analysis of a Pedestrian Lower Legform Model (보행자 다리 하체 모형의 차량 충돌해석)

  • Kim, Jin-Gon;Park, Yong-Kuk;Kim, Jung-Yun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.2
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    • pp.52-56
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    • 2012
  • Recently, the pedestrian protection regulations of Europe and Japan are becoming more stringent. However, it is difficult to evaluate the performance of protection because each regulation has different test conditions such as dummy, impact speed and so on. In this study, we construct a finite element model of pedestrian lower legform impactor prescribed in EEVC (European Experimental Vehicle Committee) W/G 10, and performed a impact analysis between the impactor and the front end module of vehicle. The simulations are carried out by using LS-DYNA3D, which is a well-known nonlinear dynamic simulation software. The analysis results according to various impact location show the impact characteristics of the lower legform.

Study on a reduction of railway vibration using impact dampers (충돌 댐퍼를 이용한 레일 진동 저감 연구)

  • Yang, Wonseok;Ahn, Sangkeun;Koh, Hyoin;Park, Junhong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.119-120
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    • 2014
  • This study presents an development of impact damper and its application to reduction of railway vibration from moving roads. The impact damper for reducing trnsverse vibration from moving loads were designed and verified using simple dynamic model. To verify the performance of the impact damper, the vibration of a simplified beam with the impact damper was measured. The performance on reducing vibration for different clearance and mass ratio of the damper was investigated. The numerical solutions were verified using the experimental results from a simplified beam. The result can be utilized to reduce the rolling noise from high-speed trains.

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Impact characteristics of the stainless sheet on the fixed boundary condition (고정형 조건에서의 스테인레스 강판의 충격 특성)

  • Ahn, Dong-Gyu;Moon, Kyung-Je;Jung, Chang-Gyun;Han, Gil-Young;Yang, Dong-Yol
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.48-53
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    • 2007
  • The objective of this paper is to investigate the influence of impact conditions on the impact characteristics of the stainless sheet for the case of the fixed boundary conditions. In order to examine impact characteristics of the sheet, three-dimensional finite element analyses and impact tests have been performed. High speed tensile tests have been carried out to obtain strain-stress relationships including the effects of the strain rate. In order to improve an accuracy of the FE analysis, the hyper-elastic model and the damping factor have been introduced. The results of the FE analyses and the impact tests have been shown that the diameter of the impact head does not affect the absorption energy of the stainless sheet. In addition, it has been shown that the absorption rate of energy maintains almost 82.583.5 irrespective of the impact energy level and the diameter of the impact head. From the results of FE analyses, the variation of stress and strain energy in the stainless sheet has been quantitatively examined.

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