• 소음진동
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• 제9권6호
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• pp.1131-1136
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• 1999

NIC@E is the software developed by authors. The program provides the noise level in outdoors due to various noise source types : construction machines including blast sources, railroad vehicles and automobiles. It operates in the Windows system. In this paper, a highway traffic noise has been evaluated using various types of approach : Ray-tracing method, NIRI method, JAS method. In order to compare the noise estimation performance for various models, a measurement is conducted on a 8 lane express highway at the distance of 25 m and 50 m from the lane. The result shows that the ray tracing and JAS model predict the measured value well within 2dB deviaton. The NIRI model, however, underestimates the highway noise level, as the distance between the source and receiver increases.

• 한국자동차공학회논문집
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• 제9권6호
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• pp.195-200
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• 2001

Composites have wide applications in aerospace vehicles and automobiles because of the inherent flexibility in their design for improved material properties. Composite tribes in particular, are potential candidates for their use as energy absorbing elements in crashworthiness applications due to their high specific energy absorbing capacity and the stroke efficiency. Their failure mechanism however is highly complicated and rather difficult to analyze. This includes fracture in fibres, in the matrix and in the fibre-matrix interface in tension, compression and shear. The purpose of this study is to investigate the energy absorption characteristics of CFRP(Carbon Fiber Reinforced Plastics) tubes on static and impact tests. Static compression tests have been carried out using the static testing machine and impact tests have been carried out using the vertical crushing testing machine. Interlaminar number affect the energy absorption capability of CFRP tubes. Also, theoretical and experimental have the same value.

• International Journal of Precision Engineering and Manufacturing
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• 제7권4호
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• pp.23-27
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• 2006

Rubber is used in many industrial products, such as hoses, rubber belts, and oil seals. In particular, more than 200 rubber parts are used in automobiles. The design technology of these parts is largely dependent on field experience, which leads to lengthy and expensive developing procedures. However, with the help of recent developments in nonlinear computer analysis, new rubber products can be developed at low cost. In this study, rubber injection molding design variables, such as location and number of gates, were optimized using computer-aided engineering with the cross-WLF equation to produce CLIP rubber products made from ethylene propylene diene monomer(EPDM). The validity of the proposed design was evaluated by comparison with actual forming results.

• 품질경영학회지
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• 제17권1호
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• pp.48-59
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• 1989

The motor vehicle emission is expected to be constrained strongly in the future in accordance with the current policy as to prevention of air pollution. This paper establishes a sequential rectifying inspection plan which satisfies the standard motor vehicle emission for the automobile producers who are currently producting the automobiles with catalytic converts. This plan also considered the constraint of the effective motor vehicle emission by way of rectifying the certification test in the past. In order to evaluate the performance of the inspection plan, the recent certification test data have also been applied. The result of the application has proved that the rectified sequential inspection plan presented in this paper satisfies the standard motor vehicle emission and can be the optimal economic inspection plan. As a result the inspection plan given in this paper will be contributed to constrain the motor vehicle emission most effectively.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 춘계학술대회 논문집
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• pp.141-144
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• 2002

This study presents the enhancement of forgeability of SNCM522H materials. Target parts are output shaft(OP shaft) used as components of power train for automobiles. To carry out cold forging process of OP shaft by 1 pass instead of existing 2 pass process, studies in terms of process design and heat treatment were performed. To introduce the new process, Finite element Method are accomplished, and to verify the validity of proposed heat treatment cycle, several experiments(Hardness test, Observation of optical microstructures, tensile test) are carried out.

• Tribology and Lubricants
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• 제29권3호
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• pp.186-191
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• 2013

Hydraulic systems are used to transform mechanical energy into fluid energy and vice versa. They are widely applied in various industries; e.g., they are used in automobiles, public works, rockets, machine tools, heavy construction equipment, and airplanes. Hydraulic pumps are used to transform the energy in these systems. In this study, with the basic operation principles as a starting point, I attempted to clarify how the shape of a slipper affects the lubrication characteristics under practical conditions. A swashplate with a tilt angle of zero and capable of rotating motion was used, along with other devices. A slipper was located at 45 mm eccentricity from the center of the swashplate. The results of this experiment indicated that the shape of the bottom surface of a slipper affects the load capacity, leakage flow, and lubrication characteristics and that the slipper is one of the most important parts for improving the pump efficiency.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 추계학술대회논문집
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• pp.198-201
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• 1997

Aluminum alloy sheets are considered as one of the high potential substitutes for steel sheets considering weight reduction of automobiles. However, aluminum alloy sheets have drawbacks in higher prices and inferior formability compared to steel sheets. In order to achieve good deep drawability, it is imperative to obtain well developed {111} texture which gives rise to higher plastic strain ratio. It is difficult to obtain this texture from conventional rolling and annealing processes. Therefore, an unconventional rolling process which enhances shear deformation has been experimentally studied to obtain the well developed {111} texture, which in turn gives rise to a substantial increase in plastic strain ratio.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.447-451
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• 2006

Automobiles become indispensable to our lives of modern days, however, their abrupt increase causes environmental problems. Relevant regulations domestically and internationally, therefore, have been discussed and reinforced for tackling those problems. The current test methods such as ISO 362 which have been adopted in many countries need to be reviewed to be effective, considering the changes in automobile techniques and road conditions. This research is aimed at providing counter-plans for the expected new measures by analyzing both the current and new test methods.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.130-136
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• 2001

This paper presents an of a brake pressure restriction valve to a motorcycle anti-lock brake system(ABS). In the conventional anti-lock brake system of automobiles, slip ratio as a control variable is actively controlled, which requires wheel speed sensors, ECU, and a pressure modulator. In the ABS valve that has been developed for use in motorcycles, however, the brake pressure that is close to the wheel locking pressure is preset by simple exercises and then the valve just allows to pass the wheel locking pressure and cutoff the remaining pressure. Simulation studies with a single wheel braking dynamics and lumped chassis model show that the pressure restriction valve has basic ABS functions as well as some robustness properties for the uncertain load and road conditions as well as various initial braking speeds. Field tests also show that the pressure restriction valve avoids the wheel locking effectively.

• 한국자동차공학회논문집
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• 제8권1호
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• pp.124-134
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• 2000

The power wteering system for automobiles is becoming core popular for supporting steering efforts of the drivers, especially for a parking lot maneuver. Though hydraulic power steering has been widely used for a long time, the efficiency of that is not high enough. The motor driven power steering system can solve the problems associated with the hydraulic power steering system. In this study, dynamic model and control algorithm of the ball screw type of MDPS systenem have been derived and analysed by using the method of discrete modeling technology. To improve steering feel and power steering characteristics, the additional scheme is proposed to the conventional power boosting control algorithm. Through simulations, control gain effects to the steering angle gain in the frequency domain were verified. The steering returnability and steering torque phase lag in on-center handing test were performed also.