• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.179-186
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• 2016

A study is to research crash barriers for vehicles that prevent road breakaway of vehicles and protect car passengers and pedestrians as absorbing impulse. Protection performance tests on vehicle passengers were simulated by using a LS-DYNA program. Through repetitive simulation on various speed and angles, passenger protection performance according to different impact condition was contemplated. Variable setting for the simulation was calculated as the mean weight of domestic car sales. By analyzing NASS (National Automotive Sampling System) of NHTSA (National Highway Traffic Safety Administration) of the U.S., the actual speed and collision angle section of accidents were computed. As a result, we confirmed that THIV (Theoretical Head Impact Velocity) and PHD (Post-impact Head Deceleration) are increased according to the impact speed and angle. Also, when the vehicle hit the guardrail post, we could be confirmed that the passenger protection performance greatly decreased.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.413-416
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• 2010

본 연구에서는 복합소재 교량용 방호울타리를 개발하여 컴퓨터 시뮬레이션을 통해 강재 교량용 방호울타리와 복합소재 교량용 방호울타리의 성능을 비교하였다. 구조적 강도 성능 측면에서 복합소재 교량용 방호울타리의 경우 교량용 방호울타리의 변형이 31.7%로 감소하여 강재 교량용 방호울타리 보다 강도 성능이 우수하였다. 탑승자 보호 성능 측면에서, 복합소재 교량용 방호울타리는 THIV 47.1%, PHD 49.0%로 감소하여 강재 교량용 방호울타리 보다 탑승자 보호성능이 우수하였다. 충돌 후 차량의 거동 측면에서, 복합소재 교량용 방호울타리는 이탈속도가 증가하고 이탈각도가 감소하여 강재 교량용 방호울타리 보다 충돌 후 차량의 거동이 우수하였다. 교량용 방호울타리의 비산 측면에서, 강재 및 복합소재 교량용 방호울타리는 비산이 발생하지 않았다.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.46-51
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• 2014

2,097 deaths out of 5,229 by traffic accident occurred by vehicle to vehicle crash and 855 deaths out of 2,097 occurred at side crash in 2011. Korean government adopted New Car Assessment Program to reduce the wounded and deaths at traffic accident in 1999 and side impact test has been added in 2003. 43 out of 53 vehicles tested in NCAP side impact rated 4 and 5 stars means the highest occupant protection. In this study three small class vehicles have been tested according to Insurance Institute for Highway Safety's side crashworthiness test protocol. IIHS test protocol uses 1,500kg moving barrier rather than NCAP's 950kg and the occupant protection rated Good, Acceptable, Marginal and Poor based on injury measure, structural integrity and head protection.

• International Journal of Highway Engineering
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• v.10 no.1
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• pp.123-134
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• 2008

Since the end treatments of guardrails installed on domestic roads have the shapes which can easily penetrate and turnover a vehicle, the occupant can be subjected to severe injury when a vehicle impacts the end treatments. In this study, the criteria of performance evaluation for end treatments are suggested which are suitable to domestic road circumstances. Based on the investigation for the installation and studies instances of end treatments, the mechanism of end treatments is examined and the new end treatment suitable to domestic road circumstances is suggested. The suggested end treatment was verified by computer simulation using d LS-DYNA programs and satisfied the suggested performance evaluation criteria for end treatments. And the developed end treatment was verified by full-scale vehicle crash test and satisfied the following three primary appraisal factors of the suggested performance evaluation criteria for end treatments; occupant risk criteria, structural adequacy, and after-collision vehicle trajectory. This study is the first to develop end treatments considering the occupant safety in Korea. Therefore, If the developed end treatments is installed on roads and highways, it can be expected that it will reduce the grave situation of end treatment accidents and increase the safety of roads.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.49-57
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• 2008

The performance of crash cushion systems is certified through the full scale crash tests by the standard for installation and maintenance guidelines for roadside safety appurtenance. The impact severities of impacting vehicles in collision with crash cushion systems are rated by indices THIV and PHD. Crash test results are considered to study the performance of three crash cushion systems. In case of the frontal impact or the offset frontal impact, the results show that THIV values of three systems are very close to the threshold limit for the occupant protection. Also, the results show that PHD would be improper for the occupant protection performance index. In order to improve the occupant protection performance of crash cushions, ASI needs to be included in the impact severity index.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.2
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• pp.175-182
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• 2010

A composite safety barrier for bridge has been developed and the performance of the composite safety barrier for bridge has been compared with the steel safety barrier for bridge through computer simulation. As the structural strength performance, the composite safety barrier for bridge is superior to the steel safety barrier for bridge according that the deformation of the composite safety barrier for bridge is 17.0% of that of the steel safety barrier for bridge. As the passenger protection performance, the composite safety barrier for bridge is superior to the steel safety barrier for bridge according that THIV and PHD of the composite safety barrier for bridge are 47.1% and 49.0% respectively of those of the steel safety barrier for bridge. As the behavior of the vehicle after crash, the composite safety barrier for bridge is superior to the steel safety barrier for bridge showing the increased exit velocity and the reduced exit angle. Both of the steel and composite safety barrier for bridge are not scattered in the analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.93-102
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• 2021

This paper describes the process of developing a concrete median barrier of SB4 grade with anti-glare function. The development section has a height and width of 1,270mm and 560mm, respectively. A wire mesh is placed in the center of the cross section to improve the protection performance. Collision analysis predicted that this section satisfies the strength and occupant protection performance, and that no damage to the barrier occurs. In the actual collision test, it was confirmed that this section satisfies the strength and occupant protection performance. However, damage was observed on two concrete barrier when the truck crashed. In order to improve the accuracy of the collision analysis of the concrete barrier in the future, it is considered that a study on the model development and continuous collision analysis method for domestic commercial vehicles should be carried out.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.115-125
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• 2003

The concrete median barriers are the most popular safety appurtenance that can be installed on narrow medians and are effective in keeping uncontrolled vehicles from crossing into opposing lanes of traffic. It is necessary to install and maintain median barriers because it is very difficult to reserve enough room required for medians in KOREA. Also, concrete median barriers are accepted as the actual alternatives for median barriers, mostly because they require almost no maintenance even after serious collisions. Typical concrete median barriers are 810mm high and have 596mm high glare screens on top of them. However we have experienced a number of "climb" and "roll-over" accidents of heavy vehicles and most of all, there have been some serious accidents caused by the part of broken glare screens. So the improvement study of concrete median barriers started. Prior to this study, a new type of concrete median barrier was suggested which is 1,270mm high and has no glare screens on top of it. So it was required to compare the properties of various types of concrete median barriers including the new type to find the optimal type of concrete median barrier. In this study, we have evaluated the characteristics of four types of concrete median barriers (New Jersey type, F type, constant slope type, and wall type). We have performed many computer simulations for the evaluation of the crashworthiness of them, and through the simulations we have tried to find a proper type of concrete median barrier. Through the computer simulations, we evaluated the structural stability and safety of the four types of concrete median barriers. We confirmed the structural stability and safety of them But in regard to the probability of "roll-over" of heavy vehicles, the higher concrete median barriers showed better performances than the lower. As the result of this study a new type of concrete median barrier was recommended.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.4
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• pp.11-18
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• 2011

In this study, the performance of a steel-FRP composite bridge safety barrier was evaluated through vehicle crash simulation. Surface veil, DB and Roving fibers were used for FRP. The MAT58 material model provided by LS-DYNA software was used to model FRP material. Spot weld option was used for modeling contact between steel and FRP beam. The structural strength performance, the passenger protection performance, and the vehicle behavior after crash were evaluated corresponding to the vehicle crash manual. As the result, A steel-FRP composite safety barrier was satisfied with the required performance.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.583-586
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• 2012

현대의 지속적인 기술개발과 산업발전은 삶의 질을 향상시키는 긍정적인 시각이 있는 반면 심각한 환경문제를 안고 있다. 자동차 공조기술도 지구 환경보호라는 거대한 과제와 탑승자의 쾌적성 만족이라는 두 가지 다른 관점을 동시에 충족시켜야 하는 과제를 가지고 있으며, 이 분야 산업에 전문적인 지식으로 공조 열량계 운용에 대한 경험이 대학 교육과정에서도 강조되고 있다. 본 논문에서는 대학 교육과정 특성상 장비의 활용성, 경제성, 장비설치 및 취급의 용이성 등을 고려하여 교육용으로 적합한 간이 열량계를 제작하였다. 교육 및 연구용으로 제작한 간이 열량계의 타당성을 확인하기위해 현재 가장 많이 쓰이고 있는 R134a 자동차용 냉방시스템을 구성하여 압축기 회전속도, 실내 풍량, 냉매 충전량 등을 변수로 하여 열교환기 냉방성능을 평가한 후 비교하여 교육용 열량계의 유용성을 확인하였다.