• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.226-229
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• 2006

The safety of on-going ships is one of important concerns in the view of environment and human life. The ship in bad condition is likely to be subjected to accidental loads such as collision. Once she has one or several minor collision damages in the form of circle or ellipse, her ultimate strength under compression or tension load will be reduced. Here, it is important to evaluate the reduction ratio of ultimate strength due to the damage from safety point of view. The problem of strength reduction of a plate with cutout such as opening hole has been treated by many researchers. As a result, a closed-form formula on the reduction of ultimate strength of a plate considering the effect of several forms of cutout was suggested. However, the structure of ships is composed of a plate and a stiffener so-called a stiffened plate, and it is likely to be damaged at a plate and stiffeners together in collision. This paper is to investigate the effect of minor collision damage on ultimate strength of a stiffened plate by using numerical analysis. For this study, the shape of minor collision damage of a stiffened plate was made by using contact algorithm. The deformed shape was used as an initial shape for ultimate stress analysis. Then, a series of nonlinear FE analysis was conducted to investigate the reduction effects of ultimate strength of the stiffened plate. The boundary condition was applied as simply supported at all boundaries, and the tripping of stiffener among failure mode under compression loading was neglected. These results were settled in the form of reduction ratio between ultimate of original intact stiffened plate and that of damaged stiffened plate.

• Journal of Ocean Engineering and Technology
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• v.21 no.4
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• pp.34-37
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• 2007

The safety of ships is one of the most important concerns in terms of the environment and human life. A ship in bad condition is likely to be subject to accidents, such as collision and grounding. When a ship has minor collision damages in the form of circle or ellipse, its ultimate strength will be reduced. It is important to evaluate the reduction ratio of a ship's ultimate strength that results from damages. The strength reduction of a plate with a cutout in the form of hole has been treated by many researchers. A closed-form formula for the reduction of ultimate strength of a plate, considering the effect of several forms of cutout, has been suggested. However, the structure of ships is composed of plates and stiffeners so-called stiffened plates and it is likely that plates and stiffeners will be damaged together in collisions. This paper investigates the effect of minor collision damages on the ultimate strength of a stiffened plate by using numerical analysis. For this study, the deformed shape of minor collision damages on a stiffened plate was made by using a contact algorithm and was used as the initial shape for ultimate stress analysis. Then, a series of nonlinear FE analyses was conducted to investigate the reduction effects on the ultimate strength of the stiffened plate. The boundary conditions were simply supported at all boundaries, and the tripping of stiffener was neglected. The results are presented in the form of reduction ratio between the ultimate strength of an original, intact stiffened plate and that of a damaged stiffened plate.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.107-112
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• 2013

Base on insurance vehicle collision and bodily injury claim reports, 23,655 cases of vehicle to vehicle accidents occurred in Korea 2010 are investigated in order to understand vehicle damage severities, repair costs and occupant injury types. The results of our statistical analysis reveal that minor damages with small dent or scratches on vehicle body panels which is assumed to imply during very low speed crashes are major portion of accident severities types. The most vulnerable body regions due to the real-world accident are neck. The 86.3% of total injured driver in minor rear damaged vehicles has reported neck pains and they are followed by whole bodies and head but with much lower occurrence rates.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.234-241
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• 1995

Offshore structures are exposed to higher probability of collision with ship because of their limited mobility. In general, the consequence of the collision is reported to be relatively small and it is desirable to consider minor collisions in the design stage. It is important to have a comprehensive understanding of the dynamic responses of a tubular, their main member, under collision to design offshore structure against possible accidents. It is needed to estimate the probable extent of damage of a tubular, depth of dent, affected by the time history of impact load in ender to design a tubular strong enough for collision. In this paper, dynamic behaviors of a tubular due to the lateral impact are investigated through the numerical simulations with hydrocode DYNA3D, a three dimensional elasto-plastic large deformation impact contact problem analyzing program.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.432-438
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• 2016

Whiplash injuries in low-speed rear-end collisions are the most common injuries and has been a social issue in insurance industry, such as excessive medical claim costs along with exaggerated injuries of victims and treatments from hospitals. According to the Korea Insurance Development Institute reports, the number of claims by rear-end collision was approximately 703,000, which accounts for 53.6 % of the total car-to-car collisions in 2014. Part of the neck injury claims in the Korea car insurance was approximately 28.3 %. Furthermore, approximately 98.4% of the injured persons in rear-end collisions sustained minor injuries under AIS2. In order to improve this situation as well as find out the severity of neck injuries from rear-end collision, the Korea Automobile Insurance Repair Research and Training Center conducted car-to-car rear-end crash tests that striking vehicles(SUV) collided into different sizes of struck-vehicles(small, middle, and large sedan) at the impact speeds of 8 km/h ~ 16 km/h. In order to analyze the whiplash injury, the BioRID-II was seated in each struck-vehicles, and the neck injury criteria(NIC), head contact time, maximum vehicle accelerations, and mean vehicle accelerations were calculated from values from the accelerations of the dummy and the struck-vehicles.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.69-77
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• 2021

Although accident data from the National Police Agency and insurance companies do not know the vehicle safety, the damage level information can be obtained from the data managed by the bus credit association or the bus company itself. So the accident severity was analyzed based on the side impact accidents using accident repair cost. K-means clustering analysis separated the cost of accident repair into 'minor', 'moderate', 'severe', and 'very severe'. In addition, the side impact accident severity was analyzed by using an ordered logit model. As a result, it is appeared that the longer the repair period, the greater the impact on the severity of the side impact accident. Also, it is appeared that the higher the number of collision points, the greater the impact on the severity of the side impact accident. In addition, oblique collisions of the angle of impact were derived to affect the severity of the accident less than right angle collisions. Finally, the absence of opponent vehicle and large commercial vehicles involved accidents were shown to have less impact on the side impact accident severity than passenger cars.