• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 추계학술대회 논문집
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• pp.250-253
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• 2003

This paper concerns about an experimental investigation about steering performance of tracked vehicle on extremely soft soil based on DOE(Design Of Experiment) using L8 orthogonal Array. A tracked vehicle model with principal dimensions of $0.9m{\times}0.8m{\times}0.4m$ and weight 167kg was constructed with a pair of driving chain links driven by two AC-servo motors. The tracks are configured with detachable grousers, the span of which can be varied. Deep seabed was simulated by means of bentonite-water mixture in a soil bin of $6.0m{\times}3.7m{\times}0.7m$. Turning radii of vehicle and torques of motors were measured with respect to experimental variables; steering ratio, driving speed, grouser chevron angle, grouser span, grouser height. The effects of experiment variables on steering performance are evaluated.

• 한국해양공학회지
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• 제20권4호
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• pp.37-42
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• 2006

This paper is concerned with experimental investigation of steering performance of a tracked vehicle on extremely soft soil. A tracked vehicle model with principal dimensions of 0.9 m(L)x0.75 m(B)x0.4 m(H) and weight of 167 kg was constructed with a pair of driving chain links, driven by two AC-servo motors. The tracks were configured with detachable grousers with variable span. A deep seabed was simulated by means of a bentonite-water mixture in a soil bin of 6.0 m(L)x3.7 m(B)x0.7 m(H). The turning radii of vehicle and driving torques of motors were measured with respect to experiment variables: steering ratio, driving speed, grouser chevron angle, grouser span, and grouser height. L8 orthogonal table is adopted for DOE (Design of experiment). The effects of experiment variables on steering performance are evaluated.

• 대한조선학회논문집
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• 제46권2호
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• pp.114-126
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• 2009

The authors adopt the Unmanned Undersea Vehicle(UUV), which has taken the shape of manta(Sohn et al. 2006). They call here it Manta-type Unmanned Undersea Test Vehicle(MUUTV). MUUTV is based on the same design concept as UUV called Manta Test Vehicle, which was originally built and operated by the Naval Undersea Warfare Center(Lisiewicz and French 2000, Sirmalis et al. 2001). In order to evaluate manoeuvring motion characteristics of MUUTV, numerical simulation technique has been utilized. Previous mathematical model on manoeuvring motion of MUUTV(Sohn et al. 2006) is basically adopted. Result of static experiment carried out in circulating water channel and a part of NSRDC standard model(Feldman 1979) on rotational mode are supplemented. Some of the hydrodynamic derivatives are obtained from model experiment in circulating water channel and the rest of them are estimated.

• 한국소음진동공학회논문집
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• 제22권10호
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• pp.925-931
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• 2012

The air-conditioner for railway vehicle should have vibration durability in order to operate normally in vehicle running situation. KS R 9144(vibration test methods for railway vehicle parts) is used to verify the vibration durability. The specifications of compressor, condenser and evaporator for air-conditioner in railway vehicle are standardized, but the shape and structure of pipe lines are not specified. Because the air-conditioner handler produces the pipe line arbitrarily, sometimes the pipe line is broken during the vibration durability test. In this research the cause identification and solution of pipe line breaking problem in during the vibration durability test were studied for air-conditioner of railway vehicle(diesel multiple unit). It was found that the natural frequency of pipe line is related to the pipe line breaking by experiment. A new pipe line shape was introduced by using FEA in order to avoid the resonance. The prototype new pipe line was applied to air-conditioner and the natural frequency was measured by experiment in order to verify the resonance avoidance. The vibration reduction of air-conditioner with new pipe line was reviewed by comparing to the air-conditioner with original one.

• Wind and Structures
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• 제17권5호
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• pp.479-494
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• 2013

The vehicle-induced aerodynamic loads bring vibrations to some of the highway sound barriers, for they are designed in consideration of natural wind loads only. As references to the previous field experiment, the vehicle-induced aerodynamic loads is investigated by numerical and theoretical methodologies. The numerical results are compared to the experimental one and proved to be available. By analyzing the flow field achieved in the numerical simulation, the potential flow is proved to be the main source of both head and wake impact, so the theoretical model is also validated. The results from the two methodologies show that the shorter vehicle length would produce larger negative pressure peak as the head impact and wake impact overlapping with each other, and together with the fast speed, it would lead to a wake without vortex shedding, which makes the potential hypothesis more accurate. It also proves the expectation in vehicle-induced aerodynamic loads on Highway Sound Barriers Part1: Field Experiment, that max/min pressure is proportional to the square of vehicle speed and inverse square of separation distance.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.34-39
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• 2001

The median barrier is one of the roadside hardware to prevent severe human and property damage from highway traffic accidents. The foreign standard of concrete median barrier was introduced and implemented without modification fitting to domestic vehicle and highway condition. In a car accident, median barrier doesn't protect vehicle effectively, especially for heavy vehicle such as bus and heavy truck. The purpose of this study is to develop the optimal performance design of concrete median barrier using the design of experiment with crash simulation analysis which is done by Pam-Crash that is one of the commercial crash simulation software. As a result of this study, an optimal design of concrete median barrier is obtained considering von Mises stress, volume and COG acceleration of truck.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.403-408
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• 2005

In recent years, vehicle accessories substitute steel for aluminum. But, subframe play a important role of vehicle safety. Therefore, dynamic characteristic of steel subframe is understood at real vehicle. And this is able to apply dynamic characteristic of Aluminum. At this paper, we confirm dynamic load that is operated Steel subframe with experiment And result of finite element analysis which is operated dynamic load is compared with result of experiment.

• 동력기계공학회지
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• 제20권3호
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• pp.57-63
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• 2016

This paper presents the experimental result and theoretical analysis result to investigate the correlation between the operating force, angle and locking torque for vehicle hood frame. Also, we derived the experimental equation that using the results for experiment and theory. The hood frame is switching-devices used for opening and closing the vehicle hood. It needs the correlation data between locking torques of each joint, operating force and angle of hood frame. The correlation data for torque and reaction force of hood frame obtained through experiment and theory analysis. Finally, the experimental equation of the locking torque prediction for the hood frame is derived.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.16-21
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• 1999

The diesel vehicle is relatively superior to gasoline vehicle on the fuel consumption, durability and combustion efficiency. However, exhaust emission from diesel vehicle are known to be harmful to human health and environment. The treatment technologies for the diesel exhaust gases are classified as replacement of fuel, quality control of diesel fuel, improvement of engine and aftertreatment system. The most effective for the treatment technology is known to be aftertreatment system, and this research is continuously conducted by many groups. The DOC system has many advantages of reducing particulates and harmful gaseous substances such as CO. HC. Moreover, it is simple in device structure, relatively low cost, and easy to install witout retrofitting the vehicle. In this study, experiment were conducted to analyze the effects on factors of oxidation characteristics and conversion efficiency of DOC. In experiment, test was conducted to estimate engine emission in 11,000cc diesel engine which was equipped with DOC.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.854-859
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• 2008

In a railway vehicle, contact between wheel and rail is a peculiar characteristic and variations of wheel and rail profile influence on the dynamic characteristics of railway vehicle. Thus the variations of the wheel and rail profile are very important in railway dynamics. Recently a research relating to active steering to improve the curving performance of vehicle is progressing actively at home and abroad. In this field, a pre-study for the wheel/rail contact geometry is needed and especially the variation of the wheel/rail contact geometry with wheel wear is the key design parameter to develop the controller of the active steering bogie. In this paper, we have experimentally studied to analyze the variation of the wheel/rail contact geometry with wheel wear as a pre-study to develop the active steering bogie for electric multiple unit (EMU). For this, we have made an experiment with EMU operating in curving area. We have measured the wear profiles of the wheel of the test vehicle and analyzed the wheel/rail contact geometry with a mileage of the test vehicle. In experiment with test vehicle, we have got the useful data to design the steering controller of the wheelset.