• Journal of Korean Port Research
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• v.14 no.2
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• pp.219-231
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• 2000

In this paper a complicated structural behavior in collision and its effects of energy translation to the collision bulkhead was examined through a methodology of the numerical simulation to obtain a ideal bow construction and a location of collision bulkhead against head on collision. In the present the bow structure is normally designed in consideration of its specific structural arrangements and internal and external loads in these area such as hydrostatic and dynamic pressure, wave impact and bottom slamming in accordance with the Classification rules, and the specific location of collision bulkhead by SOLAS requirement. By these studies the behavior of the bow collapse due to collision was synthetically evaluated for the different size of tankers and its operational speed limits, and by the results of these simulation it provides the optimal design concept for the bow construction to prevent the subsequent plastic deformation onto or near to the collision bulkhead boundary and to determine the rational location of collision bulkhead.

• Journal of Powder Materials
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• v.23 no.1
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• pp.54-60
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• 2016

This study focuses on fabricating silver flake powder by a mechanical milling process and investigating the formation of flake-shaped particles during milling. The silver flake powder is fabricated by varying the mechanical milling parameters such as the amount of powder, ball size, impeller rotation speed, and milling time of the attrition ballmill. The particle size of the silver flake powder decreases with increasing amount of powder; however, it increases with increasing impeller rotation speed. The change in the particle size of the silver flake powder is analyzed based on elastic collision between the balls, taking energy loss of the balls due to the powder into consideration. The change in the particle size of the silver flake powder with mechanical milling parameters is consistent with the change in the diameter of the elastic deformation contact area of the ball, due to the collision between the balls, with milling parameters. The flake-shaped silver particles are formed at the elastic deformation contact area of the ball due to the collision.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3_1spc
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• pp.566-572
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• 2013

In this study, a collision simulator for rolling stock that considers the plastic deformation of the car body and the dynamic characteristics of a coupler system was developed using Matlab/Simulink. Normally, a coupler system has functions for both connecting the individual car bodies and absorbing the impact energy. A coupler system is composed of a rubber buffer, hydraulic buffer, and deformation tube elements. The coupler system should protect the car body and prevent damage when the shunt speed is less than 10 km/h, which is the regulation speed based on the safety rule for rolling stock. However, if the shunt speed is greater than 10 km/h, a car body is plastically deformed. Therefore, the modeling of the plastic deformation of a car body should be included in a simulator. This collision simulator can provide the design parameters for a coupler system and car body.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.3
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• pp.266-271
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• 2012

The rescue methods for the marine casualties are limited due to the characteristics of operation environment of the vessel. Especially the most of marine accidents have been occurred at the bow structure of ship. Moreover the failure of bow structure may lead to catastrophic mishaps. In this paper, the extents of damage of a bow structure fracture subject to collision accident was investigated by using numerical method. The computer simulation approach by using Finite Element Method was employed to accomplish this goal. A finite element model, a 3D model of ship, has been utilized to evaluate damage of bow structure according to collision scenario. In conclusion, we have demonstrated that the plastic deformation occurred at the bow structure. Also it was shown that the collision angle clearly plays a role in determining amount of damage of ship structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.347-350
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• 2005

A ship collision analysis by finite element method is performed considering the effects of mass and speed of ship and material and shape of structures to analyze the dynamic characteristics by ship collision. From this analysis, collision load-time history and inelastic deformation of ship and structures are obtained. Dynamic characteristics are different from each other according to interaction. between ship and structures. It seems that there are lots of factor to have effects on the ship-structures interaction. But because little information is available on the behavior of the inelastic deformation of materials and structures during the type of dynamic impacts associated with vessel impact, assumptions based on experience and sound engineering practice should be substituted. Therefore more researches on the interaction between ship and structures are required.

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.28-35
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• 2000

In this paper a complicated structural behavior in collision and its effect of energy transmission to the collision bulkhead was examined through a methodology of the numerical simulation to obtain a ideal bow construction and a location of collision bulkhead against heat on collision. At present the bow structure is normally designed in consideration of its specific structural arrangement and internal and external loads in these areas such as hydrostatic and dynamic pressure wave impact and bottom slamming in accordance with the Classification rules and the specific location of collision bulkhead by SOLAS requirement. By these studies the behavior of the bow collapse due to collision was synthetically evaluated for the different size of tankers and its operational speed limits and by the results of these simulation it provides the optimal design concept for the bow construction to prevent the subsequent plastic deformation onto or near to the collision bulkhead boundary and to determine the rational location of collision bulkhead.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.199-206
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• 2011

In Korea, the current design codes for the bridge vessel collision load are based on AASHTO LRFD code which derived from the mean collision forces of the Woisin's test. To estimate the conservativeness of the code, in this study, the mean forces of head on collisions were evaluated from the mass-acceleration relationship of vessel and the deformation-kinetic energy relationship of bow those obtained from the series of nonlinear finite element analysis, and the mean forces were compared to that in AASHTO design code. As results, the variations of the mean forces versus the sizes of vessels were represented similar tendency, even those of the code are very conservative. However, the variations of mean collision force versus those of collision speeds were dominated by the plastic deformation of bow and it was differ from those of the code that have linear relationship with the collision speeds.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.04a
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• pp.195-204
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• 2000

In this paper a complicated structural behavior in collision and its effect of energy translation to the collision bulkhead was examined through a methodology of the numerical simulation to obtain a ideal bow construction and a location of collision bulkhead against head on collision. In the present the bow structure is normally designed in consideration of its specific structural arrangements and internal and external loads in these area such as hydrostatic and dynamic pressure, wave impact and bottom slamming in accordance with the Classification rules, and the specific location of collision bulkhead by SOLAS requirement. By these studies the behavior of the bow collapse due to collision was synthetically evaluated for the different size of tankers and its operational speed limits, and by the result of these simulation it provides the optimal design concept for the low construction to prevent the subsequent plastic deformation onto or near to the collision bulkhead boundary and to determine the rational location of collision bulkhead.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.1
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• pp.15-21
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• 2022

Collision analysis involving a vehicle frame that includes a battery and a battery case was performed using a carbon fiber composite material (CFRP) and a glass fiber-reinforced plastic (GFRP), which are lightweight materials. Three types of collisions were analyzed: frontal collisions, partial frontal collisions, and side collisions. The maximum stress and deformation levels were measured for each case. To evaluate the stability of ignition and explosion potential of the battery, the maximum stress of the frame was measured before measuring the direct stress to confirm whether the collision energy was sufficiently absorbed. The deformation level of the battery case was measured to confirm whether the battery case affects the battery directly.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.49-56
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• 2009

In this study, a side collision accident reconstruction using database based on the deformed shape information from the collision test using model cars is suggested. A deformation index and angle index related to the deformed shape is developed to set the database for the collision accident reconstruction algorithm. Two small size RC cars are developed to carry out the side collision test. Several side collision tests according to the velocity and collision angles are performed for establishing the side collision database. A high speed camera with 1000fps is used to capture the motion of the car. A side collision accident reconstruction algorithm is developed and applied to find the collision conditions before the accident occurs. Two collision cases are tested to validate the database and the algorithm. The results obtained by the reconstruction algorithm show good match with original conditions with regard to the velocity and angle.