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
제16권 제2호 (2014년 4월) 27건
1.
2014.04
구독 인증기관 무료, 개인회원 유료
Salt bath heat treatment is usually used but recently vacuum heat treatment is increased for the heat treatment of hot work die steels. The differences in two heat treatment processes were compared by testing the mechanical properties of heat treated products. With two different features of processes, mechanical properties such as hardness, tensile strength and impact strength of products show very different results. “In this study, salt bath heat treated products” showed higher tensile strength and impact strength than vacuum heat treated products but hardness was not much different. These lower mechanical properties of vacuum heat treated products are due to differences in heating and quenching process
4,000원
2.
2014.04
구독 인증기관 무료, 개인회원 유료
Bar type waveguides are frequently employed as a buffer rod between ultrasonic senor and hard-to-access object in many measurement applications. Difficulty in pulse echo measurements using a buffer rod is caused by spurious echoes due to reflection, mode conversion and interference within the buffer rod of finite size. These spurious echoes degrade the signal to noise ratio (SNR) because of their possible interference with desired target signals. A tapered buffer rod or rods with non-symmetrical cross sections were used before to reduce these unwanted spurious echoes. In this paper, we propose signal processing techniques to remove the spurious echo signals. Experiments were performed in order to examine the refocusing and recovering the initial input waveform in the long range propagation of ultrasonic waves in cylindrical waveguides. Two different time reversal processes (regular TR and reciprocal TR or inverse filtering) are tested and the experimental results were compared
4,000원
3.
2014.04
구독 인증기관 무료, 개인회원 유료
This research is to investigate the performance analysis of turbine for power generation with three different numbers of the nozzle vane in the turbine. Velocity, pressure. and temperature distributions of fluid over the flow domain of the turbine are numerically calculated for the optimum design of nozzle with two different rotational speeds of the turbine blade (1000 and 1500 RPM). Ultimately, the energy-efficient and maximum power-generated shape of the nozzle vane are determined through three different maximum Mach number of the flow with three shapes of the nozzle vane (10, 18, and 24 EA).
4,000원
4.
2014.04
구독 인증기관 무료, 개인회원 유료
Many countries of the world has been devoting a lot of effort to reduce carbon emission. In order to reduce carbon emission, the high efficiency engine has been studied in the automotive industry. Of these, the spread and research of the diesel engine in Europe center are active. However the combustion characteristic of diesel engines have disadvantages of much NOx and soot emissions. In this study, the optimum regeneration point of the forced regeneration type DPF(Diesel Particulate Filter) that was equipped in medium-duty diesel vehicles using a mechanical fuel injection system have studied. DPF that is applied to the medium-duty diesel vehicle has a bent inlet pipe. The flow distribution characteristics of DPF according to the influence of the bent pipe have investigated. The flow distribution characteristics of DPF according to variation of the engine operating condition is considered to be useful data In order to decide the optimum regeneration point.
4,000원
5.
2014.04
구독 인증기관 무료, 개인회원 유료
The two experiments were done on stationary car at 800rpm, 1500rpm and running car on oscilloscope and chassis dynamometer at the speeds of 20km/h, 60km/h. In this experiment, the relativity between waveform, exhaust emissions and fuel consumption through two experimental methods were measured in case of cars with failures in MAP sensor, O sensor, spark plugs. The following results are obtained by analyzing the data relativity between two experimental methods, such as stationary and running tests. A simple stationary test under the maintenance of a decrepit gasoline vehicle would be realistic possibility to predict the fuel consumption and the exhaust emission comparable to results of running test with a chassis dynamometer.
4,000원
6.
2014.04
구독 인증기관 무료, 개인회원 유료
In this study, tapered double cantilever beam bonded with aluminum foam composite is modelled and analyzed by finite element analysis. The bonding strength on Mode II of this structure is evaluated and investigated. In cases of inclined angles of 6°, 8° and 10°, maximum equivalent stresses occur 1.29, 1.59 and 2.6 MPa respectively at the range of forced displacement of 5 to 6 mm. And maximum reaction forces become 186, 208 and 235 N individually at this range of displacement in these cases. By the analysis result on 3 kinds of models, the maximum reaction load increases as angle of inclination of model increases. And the elapsed time to approach the maximum load and the time to disappear away become shorter. This study result can be applied into the real composite structure with aluminum foam in case that the surface bonded with adhesive is inclined. This fracture behavior can also be investigated and the impact property can be examined
4,000원
7.
2014.04
구독 인증기관 무료, 개인회원 유료
Fuel pump of a vehicle is a device to supply the fuel from fuel tank to engine. This study analyzed the pulsatility on the shape of fuel supply pipe using a CFD(Computational Fluid Dynamics). Numerical analysis was performed to use 3-dimensional incompressible k-ε turbulent model with measured pressure values at an exit by an experiment. Simulation models used commercial and improved model. In this study, the characteristics of the pulsatility reduced in improved model compared to those in commercial model. The pressure loss, which occurs at the flexure, was effective to pulsatile reduction. Commercial and improved model differed by numbers of flexure. The number of flexure between inlet and outlet decreased the difference of velocity and pressure. Therefore, the design of fuel supply pipe should be considered numbers and shape of flexure.
4,000원
8.
2014.04
구독 인증기관 무료, 개인회원 유료
This paper shows the feasibility on the application of E-glass fiber/epoxy(GFRP) composite materials to an automotive leaf spring. In order to keep much lighter weight by replacing the steel with the composite material, it is important to optimize the material parameters and design variables consisting of the structure. This paper focused on the effects of material compositions and its fiber orientations for estimating the static behaviors of leaf spring. First of all, basic material properties of GFRP composite were measured by five types of coupon specimens from ASTM standard test. The reverse implementation was also done to obtain the complete set of in-situ fiber and matrix properties from ply test results. Finally, the static spring rates was examined for the variation of thickness and material parameters such as fiber angles and resin contents of composite leaf spring.
4,000원
9.
2014.04
구독 인증기관 무료, 개인회원 유료
25% offset high speed frontal impact is the vehicle will crash left 25%(Quarter of the width of the vehicle). 47.6% of drivers killed in vehicle alone and car to car frontal impact occurred in frontal impact small overlap. Study on the occupant protection performance of 25% offset(small overlap) high speed frontal impact results are as follows. In terms of vehicle occupant protection performance, body structure was excessive intrusion into the passenger room and showed such improvement is needed for the design. This is due to a collision risk with the passenger and the solid body increases the risk of injury, showed that improvement is needed. To strengthen the safety of the future, propose improvements on the evaluation results of a statistical analysis and test of the industry and the policy makers.
4,000원
10.
2014.04
구독 인증기관 무료, 개인회원 유료
In this study variable radius pulley is proposed, and the proposal should be applied to pulley of CVT. Variable radius pulley consists of two disks and sliding pins. Phase difference of two disks make a change pitch diameter. Therefore change speed is accomplished by changing pitch diameter of pulley. In this paper analysis of rotating force for slot variation of the rotary disk of variable radius pulley was performed. The results of analysis are appropriate to put to practical use of the variable radius pulley.
4,000원
11.
2014.04
구독 인증기관 무료, 개인회원 유료
This research is to study on the optimum design of the wind power generation blade with three different shapes of the wind turbine blade and three air input speeds (7, 10, 15m/s). In order to perform this numerical analysis, velocity, pressure, and temperature distributions of fluid over the flow domain of the turbine blade and also pressure coefficient and ratio of the Lift to Drag force are numerically calculated for the best design shape of blade using commercial CFD code. Finally, the energy-efficient and optimum shape of the wind turbine for power generation are determined with the sequence of case1, case2, and case3.
4,000원
12.
2014.04
구독 인증기관 무료, 개인회원 유료
In this paper, cycle performance characteristics of a cascade refrigeration system with internal heat exchanger for cascade heat exchanger using alternative freon refrigerants is presented to offer the basic design data for the operating parameters of the system. This system considered in this study is consisted of a high temperature cycle using Freon refrigerant R23, R508B and low temperature cycle using Freon refrigerants R22, R507A. The operating parameters of this system include subcooling and superheating degree, evaporating temperature, compressor efficiency, and so on. The main results were summarized as follows : The COP of cascade refrigeration system using R23/R507A is the highest results in this study. The COP of cascade refrigeration system with internal heat exchanger only in high temperature cycle is the highest value among three cycle, such as only low temperature cycle, only high temperature cycle and all the cycle
4,000원
13.
2014.04
구독 인증기관 무료, 개인회원 유료
In the world economy and the shipping industry, container, bulk carriers and oil tanker vessels are undergoing a bigger difficulty because of the imbalance on supply and demand with the view that ship's loading capacity is exceeded. For this reason, shipping companies are trying to reduce the operating cost through slow steaming. Thus, under this condition of continuous recession in shipping industry, saving on fuel consumption is the main issue. In this study, tests were conducted to find out the method of reducing fuel oil consumption by economically operating the ships, taking into account the main engine power and speed. The subject vessel's fuel consumption compared to the output is lower near the range of 138~157RPM. The engine speed showed significant increment to 144RPM and fuel consumption increased rapidly compared to the engine speed at 15knots and above. During sea trial test, the subject vessel's specific fuel rate(SFR) was 134.25[g/BHPh] while the calculated value after 10 years of operation is 137.1[g/BHPh] at speed range of 148~150RPM which is 70% of the load and this indicates an increase of approximately 2.1%.
4,000원
14.
2014.04
구독 인증기관 무료, 개인회원 유료
This paper presents the theoretical analysis for the flow driven by surface tension and gravity force in an inclined circular tube. The present study introduces detailed mathematical procedures for Casson viscosity model. The equations of velocity distribution and flow rate are developed to describe the displacement of a non-Newtonian fluid that continuously flew into a circular tube by surface tension. The equation of modified volumetric flow shows the complicated form of (10) due to yield stress term, and the equation of velocity distribution which includes the yield stress and inclination angle of circular tube is composed of terms of r and rc as form of (14).
4,000원
15.
2014.04
구독 인증기관 무료, 개인회원 유료
The characteristic test define the thiele-small parameters and the speaker is modeled to linear or non-linear model by thiele-small parameters. The performance test is carried out the sound quality by feeling test(subjective test) and objective test. The feeling test has many problems in a viewpoint of reliability, repeatability and preference that are related to judge. The study on the correlation between feeling test and objective test are carried out in some researches and introduce the loudness, sharpness, roughness and fluctuation strength. In this study, the loudness characteristics, which is related to sound quality, of the woofer speaker that are fitted to the domestic vehicle is investigated by measurement
4,000원
16.
2014.04
구독 인증기관 무료, 개인회원 유료
In this study, carbon fiber reinforced plastic and aluminum foam used in impact absorber are assembled and modelled. These models are investigated by impact simulation and verified by experimental data. Impact energies of 30 J, 60 J and 100 J are applied on these specimens by striker. For example the experiment for impact energy of 30 J is done and verified by referring to analysis result. As the structural safeties of these assembled composite materials can be anticipated through this study result, these simulation analysis results can be applied into real field.
4,000원
17.
2014.04
구독 인증기관 무료, 개인회원 유료
4,000원
18.
2014.04
구독 인증기관 무료, 개인회원 유료
The loudspeaker is the directly radiated speaker which generates the sound by the vibration of cone paper. Therefore the shape and the vibration characteristics of th cone paper is important factors affecting the performance of speaker. The vibration mode of cone paper is piston mode that vibrates to the up-down direction, and we can see the divided vibration in the higher mode. Because the loudspeaker has a damper, the vibration mode is different to the mode of the only cone paper. In this study, the vibration mode of cone paper which considering the damper and the effects of the damper diameter were investigated by finite element method
4,000원
19.
2014.04
구독 인증기관 무료, 개인회원 유료
To estimate weld quality of the resistance spot-welding, the acoustic emission features are investigated from the total acoustic emission signal at the single-spot weld. Typically, the resistance spot welding process consists of several stages: set-down of the electrodes, squeeze, current flow, forging, hold time, and lift-off. Various types of acoustic emission response corresponding to each stage can be separately analyzed by using back-propagation neural network classifier and wavelet transform technique. The presented machine learning results provide a validation for using back-propagation neural network and wavelet transform technique as a valuable insights into the resistance spot-welding process. Especially, a wavelet transform technique is demonstrated and the plots are very powerful in the recognition of the acoustic emission features
4,000원
20.
2014.04
구독 인증기관 무료, 개인회원 유료
This paper carried out design in order to reduce the process of asymmetric pinch yoke, one of the important parts which transfer power to wheels through gearing box in automobile steering system. The purpose of the study is to reduce prime costs and strengthen competitiveness by designing the total 8 processes including the up-setting and forging process of the No. 1 as the forging process the current method of production. The process with die stress analysis by using the finite element method have been carried out through new optimal die design. As this study result, it is expected that die life can be secured as excellent material flow and caused by forming load. A prototype has been produced by basis of the analysis result and the reduction of the process was successful. As the unit price is lower than that of the current process, the competitiveness can be expected.
4,000원
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