• The Journal of the Petrological Society of Korea
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• v.21 no.2
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• pp.59-87
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• 2012

Recent studies reveal that eclogite formed in the Hongseong area and post collision igneous rocks occurred throughout the Gyeonggi Massif during the Triassic Songrim Orogeny. These new findings derive the tectonic model in which the Triassic Qinling-Dabie-Sulu collision belt between the North and South China blocks extends into the Hongseong-Yangpyeong-Odesan collision belt in Korea. The belt may be further extended into the late Paleozoic subduction complex in the Yanji belt in North Korea through the Paleozoic subduction complex in the inner part of SW Japan. The collision belt divides the Gyeonggi Massif into two parts; the northern and southern parts can be correlated to the North and South China blocks, respectively. The collision had started from Korea at ca. 250 Ma and propagated to China. The collision completed during late Triassic. The metamorphic conditions systematically change along the collision belt:. ultrahigh temperature metamorphism occurred in the Odesan area at 245-230Ma, high-pressure metamorphism in the Hongseong area at 230 Ma and ultra high-pressure metamorphism in the Dabie and Sulu belts. This systematic change may be due to the increase in the depth of slab break-off towards west, which might be related to the increase of the amounts of subducted ocecnic slab towards west. The wide distribution of Permo-Triassic arc-related granitoids in the Yeongnam Massif and in the southern part of the South China block indicate the Permo-Triassic subduction along the southern boundary of the South China block which may be caused by the Permo-Triassic collision between the North and South China blocks. These studies suggest that the Songrim orogeny constructed the Korean Peninsula by continent collision and caused the subduction along the southern margin of the Yeongnam Massif. Both the northern and southern Gyeonggi Massifs had undergone 1870-1840 Ma igneous and metamorphic activities due to continent collision and subduction related to the amalgamation of Colombia Supercontinent. The Okcheon metamorphic belt can be correlated to the Nanhua rift formed at 760 Ma within the South China blocks. In that case, the southern Gyeonggi Massif and Yeongnam Massif can be correlated to the Yangtz and Cathaysia blocks in the South China block, respectively. Recently possible Devonian or late Paleozoic sediments are recognized within the Gyeonggi Massif by finding of Silurian and Devonian detrital zircons. Together with the Devonian metamorphism in the Hongseong and Kwangcheon areas, the possible middle Paleozoic sediments indicate an active tectonic activity within the Gyeonggi Massif during middle Paleozoic before the Permo-Triassic collision.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.109-114
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• 2011

An impeller is difficult to machine because of severe collision due to the complex shape, overlapping and twisted shape that form impeller blades. So, most CAM software companies have developed CAM module for manufacturing impeller in addition to their CAM software. But it is not still easy for inexperienced users to machine impellers. The purpose of this paper is the development of automatic CAM module for manufacturing impeller(E-ICAM) which is based on visual basic language and it is used CATIA graphical environment in order to be easily machining impellers. Automatic CAM module for manufacturing of impellers generates tool path, and proposes recommended cutting condition according to the material of stock and tool. In addition, it has also included a post processor for 5-axis control machining. Therefore the user can easily machine impellers using this automation module.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.503-512
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• 2014

In this paper, various tire blow-out force experiment data were collected and analyzed to obtain approximate values of related coefficients such as rolling resistance, self-aligning torque, cornering stiffness, and radial stiffness for the analysis of the motion of vehicles with tire blow-outs. These coefficients related to tire blow-outs were input into a vehicle accident analysis program to simulate and examine the effects of tire blow-outs. Various configurations and velocities of vehicle collisions without tire blow-outs were also used as reference to establish collision events of vehicle collisions with tire blow-outs. For the events, the simulation analysis was performed and collision characteristics were obtained. Consideration of tire blow-outs or damages suggested in this study will greatly contribute to more reliable vehicle accident reconstructions.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.563-571
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• 2018

In order to effectively protect a penetrator, the conically shaped protector was proposed and the protection capability was investigated. The collision and penetration of the penetrator with the protector were analyzed using dynamic finite element analysis. The post impact behaviors of the penetrator, i.e., flying velocity and the change of attitude angle, were monitored to investigate the protection capability. The flying velocity and the attitude angle are used to investigate the deviation and the penetration power respectively. The effect of rotation speed of the protector and the collision position on the protection capability is investigated in the viewpoint of deviation and attitude angle when penetrator colliding with our tank.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.205-212
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• 2003

This paper may provide a basic design data for the safer car seat mechanism and the quality of the material used by finding out the passenger's dynamic behavior when protected by seat belt during collision. A computer simulation with finite element method is used to accomplish this objective. At first, a detailed geometric model of the seat is constructed using CAD program. The formation of a finite element from a geometric data of the seat is carried out using Hyper-Mesh that is the commercial software for mesh generation and post processing. In addition to seat modeling, the finite element model of seat belt and dummy is formed using the same software. Rear impact analysis is accomplished using Pam-Crash with crash pulse. The part of the recliner and right frame is under big stress in rear crash analysis because the acceleration force is exerted on the back of the seat by dummy. The stress condition of the part of the bracket is checked as well because it is considered as an important variable on the seat design. Front impact model which including dummy and seal belt is analyzed. A Part of anchor buckle of seat frame has high stress distribution because of retraction force due to forward motion of dummy at the moment of collision. On the basis of the analysis result, remodeling and reanalysis works had been repeatedly done until a satisfactory result is obtained.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.1-11
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• 2020

Medium to large post structures installed along the roadside without proper protection can lead to serious vehicle damage and occupant injury at the impact. In North America and Europe, splitting systems such as slip base or breakaway device are used to reduce impacts. But the system has the risk of secondary accident when the splitted post falls down to the traffic or pedestrian. Sliding Post have been proposed as a way to solve this problem. By studying the crash test results of the 1.3ton and 0.9ton vehicle with 60 km/h and 80 km/h to a Rigidly Fixed Post (RFP) and Sliding Post (SP), danger of the conventional RFP and crashworthiness of the SP have been proven. While collision analysis only from the acceleration measured at the center of the vehicle assumes the motion of the post is the same as that of the vehicle, in this paper, by adding high speed film data to the analysis with vehicle acceleration could have separate the post motion from the vehicle motion. It gives better explanations on the movement of post and vehicle in each distinctive time step and provides basics to the crashworthy post design.

• The Journal of the Petrological Society of Korea
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• v.21 no.2
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• pp.151-171
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• 2012

The Permo-Triassic Songrim orogeny in the Korean peninsula was a major tectonic event involving complicated continental collisions at the eastern margin of Eurasia. Based on the previous studies on the metamorphic and deformations features of the Songrim orogeny, this paper presents metamorphic and structural characteristics and timing of the Songrim orogeny in the Taebaeksan basin, and discuss about correlation of the tectono-metamorphic evolution of the Taebaeksan basin with the Okcheon basin and the Imjingang belt with a combined analysis of bulk crustal shortening direction, metamorphic P-T and T-t (time) paths. The metapelites in the Pyeongan Supergroup in the northeastern margin of the Taebaeksan basin have experienced lower-temperature/medium-pressure (LT/MP) regional metamorphism followed by high-temperature contact metamorphism due to the Jurassic granite intrusion. The earlier LT/MP regional metamorphism produced two loops of clockwise P-T-d (deformation) paths combined with four deformation events ($D_1-D_4$). The first loop concomitant with $D_1$ and $D_2$ occurred at $400-500^{\circ}C$, 1.5-3.0 kbar, and related with growth of syn-$D_1$ chloritoid and andalusite, post-$D_1$ margarite, Ca-rich syn-$D_2$ or post-$D_2$ plagioclase. The second loop accompanying $D_3$ and $D_4$ occurred at $520-580^{\circ}C$, 2.0-6.0 kbar, and associated with the growth of syn-$D_3$ garnet and staurolite, and syn-$D_4$ and/or post-$D_4$ andalusite porphyroblasts. Furthermore the syn-$D_1$ chloritoid and andalusite porphyroblasts grew during E-W bulk crustal shortening, whereas the syn-$D_3$ garnet and staurolite, and the syn-$D_4$ and/or post-$D_4$ andalusite porphyroblasts have grown under N-S bulk crustal shortening. The similarity in the characteristics and timing of the metamorphism and bulk crustal shortening directions between the Okcheon and Imjingang belts suggest that the peak metamorphic conditions tend to increase toward the western part (Imjingang belt and southwestern part of the Gyeonggi Massif) from the eastern part (Taebaeksan basin). The E-W bulk crustal shortening influenced the eastern part of the Okcheon belt, whereas the N-S bulk crustal shortening resulted in strong deformation in the Imjingang and Okcheon belts. Consequently, the Permo-Triassic Songrim orogeny in the Korean peninsula is probably not only related to collision of the North and South China blocks, but also to the amalgamation of terrane fragments at the eastern Eurasia margin (e.g., collision of the Sino-Korean continent and the Hida-Oki terrane).

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.38-45
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• 2017

FPSO is widely used to develop deep sea oil fields and HHI has constructed ten(10) FPSOs. During these constructions, relevant structural design criteria such as yielding, buckling, fatigue, collision and impact strength were applied to verify structural safety. To apply the buckling strength evaluation for structures, the critical buckling stresses and applied stresses of relevant panels should be calculated. The plate and stiffened panels are to be idealized, which are needed much time and efforts by designers. Therefore, program development is necessary in order to evaluate the buckling strength conveniently and accurately. In this study, the buckling strength assessment system by using offshore code, DNV-RP-C201 was developed under MSC/PATRAN, pre-post program of finite element method. Graphic user interface program is written in MSC/PATRAN PCL functions. Source program to evaluate the buckling strength is developed in FORTRAN programming languages. The developed program is verified by comparing with the results of the Nauticus Hull developed by DNV Classification Society, and applied to the marine construction project conducted by Hyundai Heavy Industries LTD.

• 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 Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.353-356
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• 2002

In vehicle accidents, the rolling, pitching, and yawing which are produced by collisions affect the motions of vehicle. Therefore, vehicle behavior under impact situation should be analyzed in three-dimension. In this study, three-dimensional vehicle dynamic equations based on impulse-momentum conservation principles under vehicle impact are introduced for simulation. This analysis has been performed by the real vehicle impact data from JARI and RICSAC. This study suggested each system modeling such as suspension, steering, brake and tire as well as the appropriate vehicle behavior simulation model with respect to pre and post impact.