간행물
한국기계기술학회지 KCI 등재 Journal of the Korean Society of Mechanical Technology 韓國機械技術學會誌
- 발행기관 한국기계기술학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1229-604X (Print)2092-0385 (Online)
- 수록기간 1999 ~ 2024
- 주제분류 공학 > 기계공학 공학 분류의 다른 간행물
- 십진분류KDC 550DDC 620
권호리스트/논문검색
제17권 제4호 (2015년 8월) 25건
학술연구
1.
2015.08
구독 인증기관 무료, 개인회원 유료
This study is a duralumin and applying heat to the STS-wide measurement range is used, the surface temperature by using the temperature of studying the non-destructive testing of a new paradigm to estimate the position and size of a structure defect purpose. STS and duralumin which has a structure defect is applied a heat by a heater. Its difference of STS and duralumin surface temperature is measured using IR thermography. The estimated result of the STS and duralumin experiment and that of theoretical analysis of PDE are compared and analyzed to diagnose the STS and duralumin defect. Moreover, this study can save time and money and improve accuracy contrast to the existing ultrasonic NDE experiment. In addition, the new paradigm of NDT/NDE by reverse-engineering is going to be valid if the data of thermal analysis and temperature distribution from the specifications of many materials is accumulated and verified. In this study, the average surface temperature of the STS in the same heating condition was 4.53 ° K higher than that of duralumin and both of the surface temperature showed an inflection point in the defect 2.5mm.The maximum surface temperature difference was formed on the 2.5mm, and the study proves its reliability because the average surface temperature of the STS and duralumin was 0.74°K, 0.45°K higher than the theoretical surface temperature.
4,000원
2.
2015.08
구독 인증기관 무료, 개인회원 유료
This paper studies on the effect of kurtosis on fatigue life. A typical vibration test machine uses a normal distribution signal. However, the vibration signal generated in the actual operating environment is a non-normal distribution signal with kurtosis. In this paper, a signal which has the same power spectral density, but has different kurtosis is generated using the Zero Memory Non-Linear(ZMNL) method. The power spectral densities of these two signal will coincide within ±3dB. Fatigue damage spectrum(FDS) computed with a normal distribution signal and FDS computed with a non-normal distribution signal generated using the ZMNL method are compared. FDS computed using the normal distribution signal of kurtosis 3 will show a big difference over the 100Hz with FDS computed using the signal of kurtosis 6. This paper shows through such FDS comparison that a difference in fatigue life prediction may result in if a vibration profile which does not consider kurtosis occurring in the operating environment of a product is used in a vibration test.
4,000원
3.
2015.08
구독 인증기관 무료, 개인회원 유료
The major complaint of hybrid vehicle driver is that real fuel economy is lower than the certified fuel economy. Therefore, it is important to analyze the cause of low fuel economy and to improve the fuel consumption at real driving condition. In this study, the various speed profile is measured by driving urban road with considering different traffic jam. By using backward simulation, the fuel economy characteristics of the acquired driving modes are analyzed. From the simulation results, the operating points of engine and motor analyzed and the cause of decrease of real fuel economy is examined.
4,000원
4.
2015.08
구독 인증기관 무료, 개인회원 유료
Zermelo's navigation problem is that the ship reaches a particular target point in the minimum-time when it travels with a constant speed in a region of strong currents and its heading angle is the control variable. Its approximate solution for the minimum-time control may be found using the calculus of variation. However, the accuracy of its approximate solution is low since the solution is based on graph or table form from a complicated nonlinear equations. To improve the accuracy, we use a neural network. Through the computer simulation study we have found that the proposed method is superior to the conventional ones.
4,000원
5.
2015.08
구독 인증기관 무료, 개인회원 유료
The objective of this study is to investigate the effect of operating conditions on the performance of small HSDI compression ignition engine. Combustion and exhaust emission characteristics of engine were studied by using CFD simulation with ECFM-3Z combustion model. The conditions of simulation were varied with injection timing, injection pressure, and operating speed, and the results were compared in terms of combustion pressure, rate of heat release, NOx and soot. It was found that as injection timing was advanced and injection pressure is increased, combustion pressure and rate of heat release were increased. As a result, NOx generation is increased. Soot generation is also increased due to the wall film caused by the increase of the injection pressure and locally the rich mixture caused by the effect of the advancing of injection timing.
4,000원
6.
2015.08
구독 인증기관 무료, 개인회원 유료
This study describes the effects of canola oil biodiesel (BD) blended fuel on the combustion performance and emission characteristics in a 4-cylinder common-rail direct injection diesel engine. In this study, with the increasing of engine loads, the biodiesel blend fuels(100 vol.% ULSD and 0 vol.% biodiesel blend, BD0; 80 vol.% ULSD and 20 vol.% biodiesel blend, BD20; 0 vol.% ULSD and 100 vol.% biodiesel blend, BD100; ULSD: ultra low sulfur diesel) were used at an engine speed of 1,500rpm. The experimental results showed that with the increasing of biodiesel blend rate, the combustion pressure decreased slightly at engine load of 20~60Nm. However, the rate of heat release (ROHR) increased clearly and ignition delay time was shortened. With the increasing of biodiesel blend rate, the carbon monoxide (CO) and particulate matter (PM) emissions were more decreased at all of the engine loads.
4,000원
7.
2015.08
구독 인증기관 무료, 개인회원 유료
Cooling towers have been widely applied to control the indoor temperature in the residential area and the living space. At operating the cooling towers, motor, fan and dropping water produce noise and vibration, which diffuse through the air or the solid object, polluting the environment. The standards can be used at estimating noise and vibration emission by showing remarkable economic or social benefits. The purpose of this study is to show the characteristics, measurement methods for the evaluation of noise and vibration in cooling tower.
4,000원
8.
2015.08
구독 인증기관 무료, 개인회원 유료
We developed the memory storage type instrumentation device for measuring trajectory of small flying object. The instrumentation device is small enough to install into the flying object and has a 6-axis MEMS sensor and 3 AD channels for measuring flying data of object. In this paper, we specially focused on the measuring of flying trajectory of the sabot using developed device. The sabot which supports missile during carriage breaks away from missile by mechanical and aerodynamic force when missile gets out of canister. The flying trajectory of sabot should be designed not to collide with any equipments around the launcher. In order to find out the flying trajectory of sabot, the developed instrumentation device was adopted in experiment. We have proved effectiveness of the developed instrumentation device by comparing acquired results using the hi-speed camera.
4,000원
9.
2015.08
구독 인증기관 무료, 개인회원 유료
There are many researches about UGV mechanism regarding uneven terrains such as mud, sand, gravel, and vertical obstacle. This paper introduces a mobile mechanism to overcome the vertical obstacle for the UGV. Moreover, this paper proposes an asymmetric mechanism of wheels to overcome obstacle. Major system geometry parameters such as will be determined under certain constraints. Several mobile mechanisms will be compared with the proposed system.
4,000원
10.
2015.08
구독 인증기관 무료, 개인회원 유료
Flow visualization of Butterfly valve is tested five cases(15°, 30°, 45°, 60° and 90°) of vlave opening angle. Measurement by the PIV(Particle Image Velocimetry) was conducted to investigate the flow characteristics of butterfly valve about discharge of dam.. Flow behaviors such as instantaneous and time-mean velocity vectors are investigated each cases. The results from flow visualization using PIV through the video which do not contain a cavitation phenomenon was confirmed in accordance with the valve opening. Performs valve opening and the flow properties of the Karman vortex generated by the frequency analysis is 90° was calculated the frequency of the butterfly valve applied to the actual dam. Butterfly valve for the emergency discharge valve is susceptible to cavitation caused by the valve opening 90° and repeat the cycle in the valve side of the vortex emission system is a high possibility of damage due to fatigue.
4,000원
11.
2015.08
구독 인증기관 무료, 개인회원 유료
The chassis frame generally consists of side members, cross beams, and several mounting brackets. Strength and fatigue behaviors of welded joints between members and brackets in a frame are a very complex phenomena, which comes basically due to the structural geometry, non-homogeneous material, and welding residual stresses. Therefore, the prediction of fatigue life for the welded structure is very difficult compared to that for the simple geometry. This paper presents the structural and fatigue analysis results for a body frame and welded joints under system durability loads. In order to fatigue assessment of welded joints, local stress approach is used for its simplicity, which is based on the several empirical S-N curves that are associated with welded joint types and loading modes. The estimated fatigue cycles of the welded areas in a frame were satisfied the target cycles under system load conditions.
4,000원
12.
2015.08
구독 인증기관 무료, 개인회원 유료
The study on ice thermal storage system is to improve total system performance in actual air-conditioning facilities. To obtain the high charging and discharging efficiency in ice thermal storage system, the improvement of thermal stratification is essential, therefore the process flow must be piston flow in the cylindrical type. In the charging process, in case of inlet flow rate the thermal stratification has a tendency to be improved with the lower flow rate and smaller temperature gradient.
The experimental results are as follows.
(1) In case of Thermal storage, the stable stratification is formed with 2LPM and 4LPM after τ=0.5 and the temperature of inlet brine rises. therefore because of the heat conduction effect of Ice Ball and delay of inflowing water mixing, the heat flow keeps stably till τ＝1.5.
(2) In case that the flow directions inside the thermal storage tank are the upward flow in charging and the downward in discharging, thermal stratification is improved because the thermocline thickness is maintained thin and the degree of stratification increases respectively.
4,000원
13.
2015.08
구독 인증기관 무료, 개인회원 유료
An aluminum foam is the super light metal which can be adjusted with the adhesive by using the joint method. In this study, the tapered double cantilever beams(TDCB) with the type of mode Ⅲ are manufactured with aluminum foam. The fracture toughness at the joint of the structure bonded with only a adhesive can be obtained. The static analyses are carried out and verified the results by the experiment. As the results of static analyses, the reaction forces ranged from 0.30 to 0.41 kN at all specimens are shown when the forced displacements are proceeded as much as 8 to 9 mm. The tapered double cantilever specimen for mode Ⅲ with the thickness of 55 mm is carried out by the static experiment representatively to verify the analysis results. As the results of analyses and experiments are compared with each other, there is a little bit of difference between these results. So, the simulation results of this study can be thought to be confirmed. It is thought that even the only analysis data omitting the extra experimental procedure can be verified in order to use the data practically. Through the result of this study, the mechanical properties at TDCB specimens with the type of mode Ⅲ can be understood.
4,000원
14.
2015.08
구독 인증기관 무료, 개인회원 유료
Numerical analysis was carried out to investigate the variation of stress and strain characteristics for the rail device in stone board cutting system. The maximum equivalent stress and strain from the vertical load acting on the device decrease as the load moves forward. Also, the maximum equivalent stress appears near the end of left, and the equivalent force of right rail device was about 1.8 times higher than that of left rail device. The variation of stress and strain distributions was remarkable at the edge of the device, and it has a strong influence on the bottom and column. These results can be applicable to optimal design of the stone board cutting device for the system safety.
4,000원
15.
2015.08
구독 인증기관 무료, 개인회원 유료
As the property of the aluminum foam with porosity, the effect of impact is distributed through the distortion of each lattice like honeycomb at impact. So, this porous aluminum foam is widely used at the crash box or the impact absorber guard rail to prevent the damage. In addition, there is a property of low weight by the chemical bonding using the adhesive. As this study investigates the distortion property of the aluminum foam bonded with adhesive, the fracture property and the stress distribution of the bonded interface are examined. The specimen thicknesses are 25, 35, 45, 55 and 65 mm. And the torsional moments corresponding to 100, 200 and 300 J are applied at one side of bonded aluminum foam. The mechanical behaviors at the bonded interface and the fixed part are also investigated. It can be seen that the minimum specimen thickness must become 55 mm and over in order to maintain the bonding force due to the applied impact energy. The analysis result of this study at the bonded interface effected on impact can be effectively applied into the safe design of the structure with the bonded aluminum foam.
4,000원
16.
2015.08
구독 인증기관 무료, 개인회원 유료
In this study, temperature variation characteristics in a flat plate with sheath heater are investigated through experiment and numerical analysis. ANSYS fluent is used to calculate the temperature distribution in the heating plate system. Transient condition is applied to observe temperature variation with the sheath heater operation, and thermal resistance on the contacted surfaces is also considered. Experimental data agree well with numerical results obtained for heat generation rate from sheath heater, Local temperature variation on the surface of flat plate is also predicted through this simulation. There is large temperature variation in the air surrounded flat plate, especially at the top of flat plate with natural convective heat transfer. These results will be helpful in optimal design for various systems equipped with sheath heater.
4,000원
생산기술
17.
2015.08
구독 인증기관 무료, 개인회원 유료
This study developed a portable extinguishing equipment that can extinguish A-class, B-class fire. This equipment is made of Water Mist Gun, controlling board, decelerator, pump, engine, and etc,. This equipment is formed mist water when pressurized water with high pressure flows through a radial shape nozzle. As a result of several efficiency tests, it is developed nozzle and equipment that are not clogged, and improved the extinguishing efficiency. This developed equipment indicated a excellent effect of initial extinguishment of fire in a vulnerable area where it is difficult to approach such as temple, and traditional market.
4,000원
18.
2015.08
구독 인증기관 무료, 개인회원 유료
Molding trouble in injection-molded parts is caused by change of complexed molding product and molding process condition, etc. Warpage, which is one of the molding trouble, acts as possible factor which results in defect in assembly. In this study, a mold was designed to produce specimens with rib parallel to flow direction, specimens with rib perpendicular to flow direction and specimens without rib. This work researched change of warpage according to injection molding condition such as packing pressure, packing time, resin temperature in crystalline polymers(PP). Flat shape with ribs showed higher warpage than flat shape without ribs. The Specimens with ribs that are located perpendicular to the flow direction.
4,000원
19.
2015.08
구독 인증기관 무료, 개인회원 유료
In this study, the lower power consumption FET-DC contactor for golf cart and low speed electric vehicle has been designed and developed. Also, the author carrying out many measurements and tests such as an electric power consumption, current consumption, calorific value, size, volume and weight of the DC contactor for the various cases. As a result, the author found that a prototype of the lower power consumption FET-DC contactor can not only reduce calorific value, size, volume and weight but also improve an electric power and current consumption.
4,000원
20.
2015.08
구독 인증기관 무료, 개인회원 유료
The Air-shiter is a new products possible ventilation at the same time cooling or heating with integrated refrigeration and ventilation units. and is a key component of the air shifter devices and bypass damper. The air shifter devices are to convert the outdoor air, room air, supply air and exhaust air flow. And the bypass damper is device to determine a ventilation. After research and development of these systems were as follows. It is confirmed that the Air-shiter is possible ventilation at the same time cooling or heating, and outdoor air cooling in the spring or fall.
4,000원
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