• Archives of design research
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• v.16 no.3
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• pp.91-100
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• 2003

The Korea's automotive industry have been achieved remarkable growth with many original models for over 28 years since the first original model Pony had developed. And most of the early models were licensed from the other country's makers. Now it is independent with our own technologies and designs, and the automobile is one of the major exporting products of Korea. In the early times the basic design concept of a passenger car didn't reflect the characteristics of the way of domestic life, but today's Korean developed cars have speciffic characters those are distinguished to others not only in the overall body shape but also in the package layout. And it is considered that the Korean cars would have different characteristics to the others in the future. These changes would come from the ways of life of the nations characteristics and they would influence to technologies of development. And the influence would be resulted as another type of sedan which has much differences to the current sedans. The main elements and the reasons for the 'post sedan' have been observed to specify the characters of the future Korean sedan in this research.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.436-441
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• 2009

An air filter is a device to remove dust from the air supplied to the automotive engine. A requirement for the optimum air filter is to improve the capability to remove particles from the air it takes in, that is the efficiency and amount of dust collection. By removing dust from the air, the air filter prevents the engine cylinder from wear, reduces ventilation resistance, and thus improves engine output and guarantees intake performance. In order to guarantee such air filter performance, it is very important to properly seal the air filter. For passenger cars made in Korea, the air filters are fabricated with steel caps as their frames are large and their engine capacity is big. Recently however, European countries and Japan started using urethane for manufacturing the air filter, so that all foreign-made cars now have urethane filters. The urethanes used for air filters are applied in two ways: One is to use soft urethane for both top and bottom of the air filter and the other is to use soft urethane for the top and hard urethane for the bottom. Each of these method has unique problems. In this study, hard urethane is used for both top and bottom of the filter in order to improve those problems and increase the sealing efficiency. Especially for the top, NBR (rubber mold) is pre-settled in tough urethane and then the urethane is solidified through foaming, which makes it possible to develop a solid and double-sealed filter.

• Journal of Auto-vehicle Safety Association
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• v.11 no.4
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• pp.6-15
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• 2019

Since introducing the offset frontal impact test in EuroNCAP in 1997, the vehicle has been constantly changing according to its usage and purpose. As of 2019, many vehicles have been released to the public, which has led to a large structural mass difference between small, medium and large vehicles. Also, the geometry of the front of the vehicle is completely different for each vehicle and tends not to be perfectly aligned at frontal collisions. The difference in mass of each of these vehicles and less performing structures for offset crashes have led to dramatically worse outcome in a car to car offset frontal impact tests. Even though a decade later passenger cars have become much safer due to consumer test programs and regulatory requirements, the aggressiveness and compatibility that can cause damage to the opponent car in the event of car to car collision is not considered in the above-mentioned section, and therefore much improvement is needed. After many years of study to solve this problem, EuroNCAP has developed a new mode MPDB offset front test that considers the aggressiveness and compatibility that can affect the opponent cars that have collided. This paper introduces the development process of aggressiveness and compatibility evaluation method of MPDB in EuroNCAP which will be implemented from 2020. Several impact tests have been conducted at different test conditions to rate the vehicle structure performance only focused on aggressiveness and compatibility of MPDB.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5963-5967
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• 2014

Reducing the impact of collisions of cars is a major issue for reducing the injury and death of passengers. According to the statistical data of the Road Traffic Authority, the deaths from side collision accidents caused by the collision of passenger cars is greater than the deaths from head-on collision accidents. To accommodate this, vehicle designers have added a reinforcing material called the impact frame and impact beam on the inside of the door. Many experiments are needed to develop the door impact beam. These reinforcements to develop a collision experiment is essential. Collision experiments are costly and time consuming. This study used a drop Impactor to obtain the impulse and a strain experimental device was developed for this purpose. The economic costs were reduced and the ideal experiment device configuration was determined. A comparison of the experimental results with numerical value analysis revealed $3.5{\tiimes}10-3sec$ strain ranging from $3.49{\tiimes}10-3$ to $3.99{\tiimes}10-3$.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.52-63
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• 2008

The side collision reconstruction algorithm is developed using three dimensional car crash analysis. Medium size passenger car is modeled for finite element analysis. Total 24 side collision configurations, four different speed and six different angle, are set up for making side collision database. Deformation index and degree index are built up for each collision case. Deformation index is a kind of deformation estimate averaging displacement of side door of crashed car from finite element analysis result. Angle index is constructed measuring deformed angle of crashing car. There are two kinds of angle index, one is measured at driver's side and the other is measured at passenger's side. Also a collision analysis information in side of cars is used for giving a basis for scientific and practical reason in a reconstruction of the car accident. The analysis program, LS-DYNA3D is utilized for finite element analysis program for a collision analysis. Those database are used for side collision reconstruction. Side collision reconstruction algorithm is developed, and applied to find the collision conditions before the accident occurs. Three example collision cases are tried to check the effectiveness of the algorithm. Deformation index and angle index is extracted for the case from the analysis result. Deformation index is compared to the established database, and estimated collision speed and angle are introduced by interpolation function. Angle index is used to select a specific collision condition from the several available conditions. The collision condition found by reconstruction algorithm shows good match with original condition within 10% error for speed and angle. As a result, the calculation from the reconstruction of the situation is reproducing the situation well. The performance in this study can be used in many ways for practical field using deformation index and degree index. Other different collision situations may be set up for extending the scope of this study in the future.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.10-15
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• 2009

Emission regulations on greenhouse gas(GHG) in automobiles have been stringent because of global warming effect. Over 90% of total GHG emission are carbon dioxides and about 20% of this $CO_2$ emission are emitted from automobiles. In this study, 110 vehicles were tested on a chassis dynamometer and $CO_2$ emissions and fuel economy were measured in order to investigate the characteristics of $CO_2$ emission factor from passenger vehicles which are the most dominant vehicle type in Korea. The characteristics of emissions in accordance with displacements, gross vehicle weight, NIER and CVS-75 speed mode were discussed. It was found that vehicles having larger displacement, heavier gross vehicle weight, automatic transmission and specially at cold start emitted more $CO_2$ emissions. From these results, correlation between $CO_2$ emission and fuel economy was also obtained. This study may contribute to evaluate domestic greenhouse gas emissions and establish national policies on climate changes in future.

• Tribology and Lubricants
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• v.36 no.2
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• pp.88-95
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• 2020

In this study, we investigate the mechanical properties of high manganese steel, and the friction and wear characteristics of brake friction material containing this steel, for passenger car application, with the aim of replacing copper and copper alloys whose usage is expected to be restricted in the future. These steels are prepared using a vacuum induction melting furnace to produce binary and ternary alloys. The hardness and tensile strength of the high manganese steel decrease and the elongation increases with increase in manganese content. This material exhibits high values of hardness, tensile strength, and elongation; these properties are similar to those of 7-3 brass used in conventional friction materials. We fabricate high manganese steel fibers to prepare test pad specimens, and evaluate the friction and wear characteristics by simulating various braking conditions using a 1/5 scale dynamometer. The brake pad material is found to have excellent friction stability in comparison with conventional friction materials that use 7-3 brass fibers; particularly, the friction stability at high temperature is significantly improved. Additionally, we evaluate the wear using a wear test method that simulates the braking conditions in Europe. It is found that the amount of wear of the brake pad is the same as that in the case of the conventional friction material, and that the amount of wear of the cast iron disc is reduced by approximately 10. The high manganese steel is expected to be useful in the development of eco-friendly, copper-free friction material.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.117-129
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• 2010

This study presents a sensitivity analysis method for stochastic user equilibrium of multi-modal network flows. We consider a multi-modal network consisting of a road network for passenger cars physically separated from a transit network for public transport. We first establish a sensitivity analysis method with respect to arbitrary link parameters and perform a sensitivity analysis with respect to link capacity and transit line frequency as practical link parameters. Next, We establish a sensitivity analysis method and perform the sensitivity analysis with respect to modal split by passenger car and public transit. As with the elasticity of economics, these results can be important information for analyzing changes in travel behavior due to the changes in operation and policy of transportation facilities, as well as for analyzing the effects of these operational changes and policies. These results also can be utilized as a tool to constitute a multi-modal network design problem by using cooperative game theory.

• 한국가시화정보학회:학술대회논문집
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• 2006.12a
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• pp.17-20
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• 2006

Passenger safety is fundamental factor in automobile. Among much equipment for passenger safety, the air bag system is the most fundamental and effective device. Beside of the front air bag system which installed on most of all automobiles, a curtain-type air bag is increasingly adapted in deluxe cars fur protecting passengers from the danger of side clash. Curtain type airbag system consists of inflator housing, fill hose, curtain airbag. Inflator housing is a main part of the curtain-type air bag system for supplying high-pressure gases to deploy the air bag-curtain. Fill hose is a passageway to carry the gases from inflator housing to each part of curtain airbag. Therefore, it is very important to design the vent holes of fill hose for good performance of airbag deployment. But, the flow information from vent holes of fill hose is very limited. In this study, we measured instantaneous velocity fields of a high-speed flow ejecting from the vent holes of fill hose using a dynamic PIV system. From the velocity Held data measured at a high frame-rate, we evaluated the variation of the mass flow rate with time. From the instantaneous velocity fields of flow ejecting from the vent holes in the initial stage, we can see a flow pattern of wavy motion and fluctuation. The flow ejecting from the vent holes was found to have very high velocity fluctuations and the maximum velocity was about 480m/s at 4-vent hole region. From the mass flow rate with time, the accumulated flow of 4-vent hole has occupied about 70% of total flow rate.

• Journal of the Korean Society for Railway
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• v.18 no.6
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• pp.513-521
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• 2015

When a GTX travels through a deep-level underground tunnel at a speed of 180km/h, ear-discomfort in passengers due to the pressure wave generated could be an issue due to the small cross-sectional area. Therefore, appropriate pressure-tightness values for GTX trains must be secured as a countermeasure. In this paper, a 1D numerical analysis was conducted to determine the pressure-tightness coefficient which allows a pressure change meet the criteria. The pressure transients in a tunnel and in a passenger car are predicted considering an A-line underground tunnel with a length of 37km and its operation schedule. The required pressure-tightness of the car is predicted to be three seconds and 6 seconds respectively for a single track and a double- track tunnel to prevent aural discomfort in passengers. The result of this study are expected to serve as useful information to those involved in the development of various solutions to improve air-tightness of GTX passenger cars.