• Journal of Welding and Joining
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• v.33 no.3
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• pp.12-18
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• 2015

The ultimate goal of developing body is revealed the "lightweight" at latest EuroCarBody conference 2012 and the most core technology is joining process to make lightweight car body design. Accordingly, in this study, the car body assembly line for the assembly process applies to any introduction, particularly in the assembly of aluminum alloy and composite materials applied by the process for the introductory approached. Process were largely classified by welding (laser, arc, resistance, and friction stir welding), bonding (epoxy bonding) and mechanical fastening (FDS, SPR, Bolting and clinching). Applications for each process issues in the case and the applicable award was presented, based on the absolute strength of the test specimens and joining characteristics for comparative analysis were summarized. Finally, through this paper, we would tried to establish the characteristics of the joint for lightweight structure.

• Archives of design research
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• no.16
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• pp.53-63
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• 1996

With the high level economic growth and plentiful stabl izing our I iving, our car has become indispensable necessi ties of life which was the symbol of our riches. And yet, on this changes of the times, we welcomed MY CAR epoch with an explosive increase of its demand. However, compared wi th this trend, we feel actually that our level of car development technique is beyond our capaci ty to satisfying our personal fancy I ike advanced nations for buying car in quantity and quality side. On this study, I made car body color as my studing topic which was few concerning to research. I analyzed and investigated[surveyed] the state of envi ronmental facts and recent Korean passenger- car body color trend. After this work, I found out enough to solve the problem on developing car body color. And I suggest the problem solving materials as a reference to meet with the modern's fancy in the development processing of passenger car with systematicaly and effectively.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.351-356
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• 2009

In this study, we analyzed and experimented about electric continuity for human body safety from green cars. And we compared power systems of HEV and examined about human body effect of current and time. We investigated internal and external standards and regulations for human body safety from high voltage electrical equipments. Indirect contact refers to contact between the human body and exposed conductive parts. According to UNECE R100, ISO 23273-3, ISO 6469-3 and Japanese Regulation Attachment 101, electric continuity between any two exposed conductive parts shall not exceed $0.1{\Omega}$. The value of electric continuity was measured below $0.1{\Omega}$ at the actual condition of green car. We expected that the results of these experiments can utilize to data for electrical safety of green car.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.548-553
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• 2008

Low Floor buses have no steps to get on or get off the main cabin to provide the old and the handicapped with easy access. The car body for the low floor bus was designed to consider Korean physical standard, passenger capacity (standee, seated, handicapped), arrangement of vehicle components, and bus law or regulations. It was designed as an one body, without any reinforcement armature, which has light-weight sandwich constructions with glass epoxy skins, aluminum honeycomb cores and inner-frames. In this paper, torsion rigidity of the designed car body was evaluated and compared with that of a car body with reinforcement armatures in the cabin. Finite element method verified that the designed car body without reinforcement armatures could satisfy requirements of torsion rigidity.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2002.05a
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• pp.25-27
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• 2002

Most of automotive companies make use of spot welding in order to assemble car body. Even though spot welding has been developed for last 60 years, there were some limitations in upgrading production line. Laser welding has advantages In productivity and degree of freedom in design. Thanks to fast speed, we can reduce body assembly line by 80%. Also with non-contact & one-side approach, it is possible to design various car body structures. New project launched the laser welding technology in mass production has started in 1999. In this paper, a new type of cur named 'next generation vehicle (NGV)' is introduced. The car body of NGV is welded with 4㎾ Nd: YAG laser.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4707-4712
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• 2014

Considerable fuel in cars is consumed by air resistance. The flow resistance against the air stream was analyzed by flow analysis near the passenger car body. In this study, the models were used were cars available on the real market. Two velocities entered into inlet plane of flow were 80 km/h and 110 km/h using the flow analysis of CFX. As the study method, the velocity of air flow near the car and the pressure on the rear part of car body were investigated at the driving of car. The shapes of the study models were models 1 and 2, and the flow streams were four cases of 1, 2, 3, and 4. In case 1 among the four cases, the maximum pressure ($1.017{\times}10^5Pa$) on the rear part was highest and the maximum velocity (43.81m/s) of air flow near car body was fastest. The air drag force in the case of high speed (110km/h) driving a passenger car was higher than that of a normal driving speed (80km/h). The drag force at wide section area of the car body becomes higher than the narrow section area. The shape of the car body can be effectively designed to reduce the air resistance using the study results of this analysis.

• International Journal of Automotive Technology
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• v.8 no.5
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• pp.629-636
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• 2007

This paper describes the process of analyzing vehicle stiffness in terms of frequency band in order to improve vehicle handling. Vehicle handling and ride comfort are highly related to the systems such as suspension, seat, steering, and the car body design. In existing analytical processes, the resonance frequency of a car body is designed to be greater than 25 Hz in order to increase the stiffness of the body against idle vibration. This paper introduces a method for using a band with a frequency lower than 20 Hz to analyze how stiffness affects vehicle handling. Accordingly, static stiffness analysis of a 1g cornering force was conducted to minimize the deformation of vehicle components derived from a load on parts attached to the suspension. In addition, this technology is capable of achieving better performance than older technology. Analysis of how body attachment stiffness affects the dynamic stiffness of a bushing in the attachment parts of the suspension is expected to lead to improvements with respect to vehicle handling and road noise. The process of developing a car body with a high degree of stiffness, which was accomplished in the preliminary stage of this study, confirms the possibility of improving the stability performance and of designing a lightweight prototype car. These improvements can reduce the time needed to develop better vehicles.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.1
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• pp.35-41
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• 2009

Through the multibody dynamic simulation, the analysis model of the modalohr freight car of the DMT freight car was developed. By using the developed analysis model, the running dynamic characteristics was inquired through the dynamic analysis about the modalohr freight car. As the running speed and the primary suspension were increased, the lateral and vertical vibration accelerations of the car-body and the bogie were also increased. In case of the lateral vibration acceleration of the car-body, however, review should be considered since it can be influenced by the nonlinear characteristic of the primary suspension. The lateral and vertical vibration of the car-body were generated at the frequency of $2{\sim}3\;Hz$ and $7{\sim}8\;Hz$. And the lateral and vertical vibration of the bogie were generated at the frequency of $25{\sim}35\;Hz$ at the low speed section, $40{\sim}50\;Hz$ at the high speed section.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.4
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• pp.55-63
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• 2018

In recent years, with the growing interest in electric vehicles, the development of a Neighborhood Electronic Vehicle (NEV) made for urban driving is accelerating. Existing NEVs are set to ~0.3 - 0.35 with more emphasis on performance rather than minimizing air resistance. In this paper, a NEV with a streamlined car body is proposed. The shape of dolphins and sharks was applied to the car body to minimize the air resistance generated when driving. Also, the performance of the vehicle was estimated by calculating the traction force and the roll couple, etc. To check the drag coefficient of the car body, finite element analysis software (COMSOL Multiphysics) was used. The frame of the vehicle is divided into the forward and the rear parts. Carbon pipe is used for the frame by MIG welding. The car body of the vehicle was fabricated by forming carbon fiber. This study confirmed the general possibility of using NEVs through driving experiments.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.9
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• pp.9-14
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• 2020

In this study, CFX analyses were performed with flow models to minimize the flow resistance due to the windscreen on the front of a car body. The results indicated that the greater the slant angle of the windshield, the greater the maximum pressure area. The lower the slant angle of the windscreen, the smaller the area in which the air collides with the front of the car body and the more smoothly the air moves. The results of this study can be applied to increase fuel economy under driving conditions by changing the slant angle of the vehicle's windscreen.