• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.860-863
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• 2005

Dynamic model of the Korea standardized rubber-tired AGT light rail vehicle, and boundary conditions between vehicle and infrastructures (running track, guidance rail) were defined to analyze vehicular vibration behaviors occurred at the worst condition. Using the commercialized software RecurDyn, vibration accelerations of car body and bogies were analyzed. Based on the Korea performance test criteria for urban transit, vertical and lateral vibration of car body were calculated and evaluated. As the results, the Korea standardized rubber-tired AGT light rail vehicle satisfied the performance criteria and design requirement.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.273-276
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• 2004

Dynamic model of the Korea standardized rubber-tired AGT light rail vehicle, and boundary conditions between vehicle and infrastructures (running track, guidance rail) were defined to analyze vehicular vibration behaviors occurred at the worst condition for straight running track. Using the commercialized software RecurDyn, resultant forces and vibration accelerations of car body and bogies were analyzed. Based on the Korea performance test criteria for urban transit, vertical and lateral vibration of car body were calculated and evaluated as wearing condition of guide wheels. And resultant forces between bogie guidance frame and guide rail in straight running track were analyzed. As the results, the Korea standardized rubber-tired AGT light rail vehicle satisfied the performance criteria and design requirement .

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1427-1437
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• 2000

In the authors＇ preceeding paper, an improved component mode synthesis (CMS) technique in which experimental data as well as finite-element data are available in sub-systems has been proposed. Thi s technique, called an improved experimental free-interface method (IEFIM), has been proved to be more accurate and more efficient than the conventional experimental CMS method based on McNeal's formulation. It is due to the facts that dynamic residual terms as well as static ones are compensated from experimentally obtained FRFs and that FRFs measured on any frequencies can be used for the compensation. In this paper, the technique is applied to the component mode synthesis of a car body structure. As a result, the applicability of the technique to a large structure is demonstrated.

• Journal of Auto-vehicle Safety Association
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• v.9 no.1
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• pp.25-31
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• 2017

Small Overlap test decided on IIHS (Insurance Institute for Highway Safety) evaluates a robustness of the car body and a passenger injury protection. A current vehicle is satisfied with a robustness of the car body for Small Overlap test but not meet the requirements of passenger injuries because it is difficult to inquire into the actual state of injury mechanism for Small Overlap test. The study shows the new injury mechanism which represents the relation between a structure of the vehicle placed with the lift foot and the low extremity injury.

• Korean Journal of Computational Design and Engineering
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• v.2 no.3
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• pp.133-141
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• 1997

In the process of car body design, various surfaces are generated from the given boundary curves. Depending upon the method of the surface generation and the quality of the boundary curves provided, the resulting surfaces may have global or local irregularities in many cases. Thus it would be necessary for the designer to evaluate the surface quality and to modify the surface or to use the different generation method based on the evaluation results. This capability is very important because the defect of the surface quality detected in the production stage will require the rework of the dies and will cause a big loss in cost and time. A method of surface interrogation using reflection line is introduced. In this paper, We applied reflection mapping to generate reflection lines on the trimmed NURBS surface. Since reflection lines are obtained from reflection mapping that uses simple and physically acceptable mapping algorithm, they can be efficiently used to simulate the reflection test on the real part in the production line.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1139-1143
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• 1991

Using industrial robots and sensors, we developed an inline car body inspection system which proposes high flexibility and sufficient accuracy. Car Body Inspection(CBI) cell consists of two industrial robots, two corresponding carriages, camera vision system, a process computer with multi-tasking ability and several LDS's. As industrial robots guarantee sufficient repeatabilities, the CBI cell adopts the concept of relative measurement instead of that of absolute measurement. By comparing the actual measured data with reference data, the dimensional errors of the corresponding points can be calculated. The length of the robot arms changes according to ambient temperature and it affects the measuring accuracy. To compensate this error, a robot arm calibration process was realized. By measuring a reference jig, the differential changes of the robot arms due to temperature fluctuation can be calculated and compensated.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.260-263
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• 2005

Fatigue fracture behavior of a hybrid joint between side-panel and under-frame by riveting and adhesive bonding has been evaluated. Two kinds of joint specimens based on real geometry were fabricated for shearing test as well as bending test. Static and cyclic loadings were used for fatigue assessment. Fatigue fracture results obtained by such experiments were reflected in modifications of design parameters of the hybrid joint.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1309-1316
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• 2002

The purpose of this study is to analyze the effects of the parameters of the suspension system in railway rolling-stock for KT-23 type passenger vehicle. According to the results of simulation and the field test, Optimal condition was obtained for the stiffness ratio of the primary spring and the secondary of the suspension system. When the stiffness ratio was increased, the vibration was increased on the car body and decreased on the bogie, and ride quality are getting worse because of increase of the vertical natural frequency of the car body. The results of this study are usefull to improve the technology of the ride quality of KT-23 type vehicle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.5
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• pp.8-14
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• 2015

Heat treatment for car body molds is mainly a manual process performed by a worker. The performance of this process is affected by workers' skill level, and has limitation in maintaining uniform product quality. In this study, we developed a diode laser heat treatment robot system that implements an OLP type simulator to overcome the limitation of manual process, and to improve and stabilize the quality level. In addition, we verified the efficiency of the robot system and mechanism stability from the early stage through design verification and simulated analysis in the development stage. In addition, we carried out a field test to study the way to establish optimized D/B for diode laser heat treatment criteria for car body molds, such as heat treatment speed, interval, etc. via site experiment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.5 s.176
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• pp.1133-1145
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• 2000

It is necessary to develop an efficient analysis method to identify the dynamic characteristics of a large mechanical structure and update its finite element model. That is because these processes need the huge computation of a large structure and iterative estimation due to the use of the first- order sensitivity. To efficiently carry out these processes, a new method, called the generalized free-interface mode sensitivity method, has been proposed in the authors' preceeding paper. This method is based on substructuring approach such as a free-interface method and a generalized synthesis algorithm. In this paper, the proposed method is applied to the model updating of a car body structure to verify its accuracy and reliability for a large mechanical structure.