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 제1호 (2015년 2월) 27건
1.
2015.02
구독 인증기관 무료, 개인회원 유료
There are many different causes of air drum brake judder noise in commercial vehicles. This study set out to identify those causes from the perspective of brake structure, not taking the environment into account. For that purpose, the investigator measured vibrations and noises in case of brake judder noise and analyzed their causes. The structural vibrations of the brake were analyzed to identify the causes with an experimental method involving O.D.S. (Operational Deflection Shape) analysis and model testing. In an effort to find directions for improvement with an analytical method, the investigator modeled the brake system in an analytical manner, correlated it with the experiment results, and tested directions for improvement in an analytical fashion. The structural rigidity of the brake that had been tested analytically was increased so that the generation frequency and structural vibration frequency of brake judder noises would not be contiguous. The parts of high structural rigidity were tested for brake judder noises with a model test and vehicle test.
4,000원
2.
2015.02
구독 인증기관 무료, 개인회원 유료
This study analyzed the thermal properties of a thermal conductive polymer polyethylene terephthalate(PET) to make it into a heat sink and evaluated the temperature properties of 10W COB(chip on board) LED(Ligth Emitting Diode) as a heat sink. This study confirmed the composition and content of inorganic compounds in PET. As a result, carbon filler content of Samples A and B accounted for 73.93 and 61.46%, respectively. Sample B included 10% more inorganic filler(Al, Mg, Si, Ca), and its thermal conductivity was 10.9 W/mk higher than Sample A. Based on the material properties, this study compared the heat dissipation properties of 10W COB LED between PET and aluminum heat sinks. As a result, the maximum temperature of PET heat sink was 4.4℃ higher than that of aluminum heat sink, and the minimum temperature outside PET heat sink was 13.6℃ lower than that of aluminum heat sink. Based on these results, PET heat sinks are inferior to aluminum heat sinks in thermal properties. However, it is considered possible to realize various designs because they have excellent formability and lightweight properties due to the lower melting point and specific gravity
4,000원
3.
2015.02
구독 인증기관 무료, 개인회원 유료
The honeycomb aluminum foam of the porous metal has the merit of the impact absorption, the soundproof, the heat conductivity, the light weight. Aluminum 6061-T6 is used at the materials for the automobile, the ship, the machine and various structures. In this study, the sandwich combined with the honeycomb aluminum foam and aluminum 6061-T6 is simulated with the impact. Two kinds of models made by use of CATIA program with 3 kinds of impact energies are analyzed by ANSYS program. As the simulation result, the maximum deformations at the cases of 1 and 2 are shown as 4.8205mm and 11.909mm respectively. And the maximum equivalent stresses at the cases of 1 and 2 are shown as 274.45MPa and 265.6MPa respectively. As the simulation result at case 1 approaches the experimental result, all simulation results can be verified in order to apply into analyzing the impact properties of the honeycomb aluminum foam sandwiches. In cases of three kinds of impact energies, the striker is not shown to penetrate the upper face sheets of case 1. At the impact energy of 100 J, the striker is not shown to penetrate the upper face sheets of case 2. At the impact energies of 200 J and 300 J, the striker is shown to penetrate the upper face sheets of case 2. It is thought to predict and improve the structural safety the composite material combined with the aluminium foam by using this study result.
4,000원
4.
2015.02
구독 인증기관 무료, 개인회원 유료
Adhensively bonded joints in dissimilar materials have been widely applied in various engineering fields such as automobiles, space vehicle, semiconductor, vessel. To establish a fracture criterion and a reasonable strength evaluation method on adhensively interfaces in dissimilar materials, it is necessary to assess fracture parameters with various bonding conditions. In this paper, through stress analysis by using the 2-dimensional elastic boundary element method(BEM), the stress singularity factors on adhensively bonded joint in dissimilar materials were investigated quantitatively, and suggested the strength evaluation method by using fracture parameters
4,000원
5.
2015.02
구독 인증기관 무료, 개인회원 유료
Recently, studies have been actively conducted on light sources which can affect the growth rate of plants by using monochromatic lights which have light wavelength or combining them into mixed lights. The studies measure Photosynthetic Photon Flux Density (PPFD) according to the change of light quality of LED light source and research on the acceleration of plant growth. With red, blue, green and white mono-chromatic lights, this study fabricated 6 mixed lights. Then, with 3 mono-chromatic lights and 6 fabricated mixed light source, the study conducted comparison analysis on what effect optical properties and PPFD have on (the growth of) a plant (radish sprouts). As the result of analysis, in the same PPFD, it turned out that the speed of plant growth was faster in red mono-chromatic lights while the speed was similar in blue and white mono-chromatic lights and mixed lights.
4,000원
6.
2015.02
구독 인증기관 무료, 개인회원 유료
Abstract The cascade refrigeration cycle system has been used mainly to obtain the ultra-low temperature. In this study, the effects of internal and outdoor temperatures at chamber on the heat capacity of fin-tube heat exchangers were examined. In addition, refrigerant line patterns as well as refrigerant type for cascade cycle were optimized. The results in this study show that the refrigerant line patterns have greater effect on the sensible capacity than the total capacity. Also, the condenser heat release rate for R717-R744 cycle varies the ratio of 46 % with outdoor temperature by comparing with that of 24% for R134a-R410a cycle.
4,000원
7.
2015.02
구독 인증기관 무료, 개인회원 유료
The general auto transmission uses the torque converter that has a good vibration damping force by launching performance and damping effect as power transfer unit. The vehicle equipped with auto transmission uses Lock up clutch system to improve the fuel efficiency. The Lock up clutch system is the major factor of the devices that increase the torque from engine to transmission in specific condition and also consist of the damper springs to transfer the torque stably. Damper spring controls the vibration of power transfer units and improve the impression of riding and durability, by being damping function on change torque from engine. In addition, not only the appearance and performance, but also these sensitive qualities as like vibration and noise can also be main factor to buy a car. Recently, in order to absorb the low vibration caused by vehicle structure vibration, the Low-stiffness damper has been on the rise. The damper spring should be considered and designed, considering the engine characteristic and direct connect of lock up clutch due to the stiffness of the spring and hysteresis has a major effects to the damper characteristic. This study can be used for analyzing the major factors to effect the NVH characteristic by evaluating the damper’s hysteresis according to change of spring stiffness.
4,000원
8.
2015.02
구독 인증기관 무료, 개인회원 유료
The study will design the structural optimization of 30W LED heat sink using the thermal conductive plastic materials. The advantages of thermal conductive plastic heat sink are having formability and being able to lighten products. A heat sink was optimized in terms of the number, and the thickness of fins and the base thickness of the heat sink, using the Heatsinkdesigner software. Also by using SolidWorks Flow simulation and thermal analysis software, the thermal characteristics of the heat sink were analyzed. As the result, the optimized heat sink has 22 fins, which are 1.5mm thick and a 3.8mm-thick base. The weight of the heat sink was 310g, and the highest and the lowest temperature were 64.93℃ and 45.96℃ respectively. Because of the low thermal conductivity of the thermal conductive plastic, the highest and the lowest temperature of the thermal conductive plastic heat sink were 14.3℃ higher and 2.19℃ lower respectively than an aluminum heat sink
4,000원
9.
2015.02
구독 인증기관 무료, 개인회원 유료
The object of this paper is to examine the noise generating mechanism at manufacturing process of metal material products. To accomplish the object; A noise generating mechanism of high noise machine, which is mounted in the small and medium size enterprise, was investigated. The measurement method of the noise for the machine by manufacturers were investigated. The noise at the 250 point of the manufacturing procrss machine in the 40 processes of the 3 factories, 3 business fields was measured. The database of the noise was built from the measurement data. The major sound sources and frequency range for the manufacturing processes of metal product machine was investigated.
4,000원
10.
2015.02
구독 인증기관 무료, 개인회원 유료
A compressor in the refrigerator uses about 80% of the total consumption power required for refrigerating cycle. In this study, we consider the auxiliary piston equipped with a valve that can be controlled to open and close in order to dramatically increase the efficiency of a linear compressor. Turbocharger using the auxiliary piston was to improve the cooling capacity and efficiency of the compressor. The numerical results show that the cooling capacity was considerably improved by approximately 40.6% compared to that of the baseline model. In addition, COP increased about 7.6% indicating that the turbocharger was very efficient
4,000원
11.
2015.02
구독 인증기관 무료, 개인회원 유료
In this paper a study on prediction of the wave resistance performance of a very large crude oil carrier(300K VLCC) was taken into account according to the changes in L/B/T. The wave resistance of the ship was calculated using the potential based panel method in which exact nonlinear free surface boundary conditions and the trim and sinkage were considered. The panel cutting method were implemented to generate the hull surface panel and the free surface panel were generated using the variable free surface method. The numerical analysis was carried out according to the 12 different ships. The wave resistance coefficients and the wave patterns of the 12 different ships were compared with each other. As a result the wave resistance of a ship was found to be significantly affected in L/B than T.
4,000원
12.
2015.02
구독 인증기관 무료, 개인회원 유료
구형 충격을 받는 필름 코팅된 유리 시스템의 거동을 개발한 유한 요소 프로그램에 의하여 연 구하고자 한다. 충격 거동을 예측하기 위하여 Sun의 higher order beam theory와 Kurapati의 generalized power law와 연계한 새롭고 효과적인 동적 유한 요소법을 제안한다. 필름 코팅된 유리 시 스템과 모놀리식 유리에 대하여 접촉력, 변형량, 운동에너지, 속도 및 응력 등을 계산한 후 결과를 비교 검토하여 코팅 시스템의 필름이 충격 손상을 방지하고 충격 저항이 우수하다는 것을 정성적 및 정량적으로 규명하였다.
4,000원
13.
2015.02
구독 인증기관 무료, 개인회원 유료
In recent years, technology has been developed the way the volume of the portable communication device is reduced but its performance is maintained. The COF(Chip On Film) packaging method is used due to the densification of the lead pitch, especially for the display driver IC. During COF packaging, lead break and film detachment could occur by the high bonding temperature and pressure, and possibility for lead interference can emerge by deformation of leads. In this study, a new double-column arrangement of leads is considered to increase lead density further than the existing zigzag arrangement of leads, and nonlinear structural analysis was carried out to examine whether the interference can occur. The results showed that stress and deformation of the corner region appear relatively higher than those of central region, and interference did not occur by the lead strain for the double-column arrangement of leads with pitch of 25μm. Therefore, double-column lead arrangement can improve lead density by about 176% compared to the zigzag lead arrangement
4,000원
14.
2015.02
구독 인증기관 무료, 개인회원 유료
In the present study, numerical analysis algorithm for the hull form optimization was taken into account using optimization algorithm. In this algorithm the sequential quadratic programming method was applied as an optimizer and the potential-based panel method was adopted to get the wave resistance coefficient as the objective function. The hull form was modified using the B-spline surface modeling technique during the whole optimization process. The developed numerical analysis algorithm was applied to the 300K VLCC and the optimized ship were compared with the original ship.
4,000원
15.
2015.02
구독 인증기관 무료, 개인회원 유료
Numerical simulations of liquid water droplets interacting with gas channel walls in a polymer electrolyte membrane fuel cell are performed with the volume of fluid (VOF) method. To investigate the effect of channel wall wettability, the contact angles of gas diffusion layer (GDL) and the side/top walls are varied as 45, 90, and 140 degrees. Two different water injection inlet locations are selected to investigate the interactions of liquid water with the different gas channel walls. As the GDL contact angle increases, the GDL surface water coverage ratio and the water volume ratio decrease. When the water injection hole is located near the side wall, the GDL surface water coverage ratio decreases and the water volume ratio increases as the contact angle of the side and top walls decreases. In conclusion, the GDL surface water coverage ratio and the water volume ratio may compete with each other to determine the fuel cell performance.
4,000원
16.
2015.02
구독 인증기관 무료, 개인회원 유료
An algebraic model for turbulent heat fluxes is proposed on the basis of the elliptic blending equation. The algebraic model satisfies the temperature-pressure gradient correlation characteristics of near-wall region and the flow center region far away from the wall. That is, the turbulent heat flux conditions for both regions are connected by the solution of the elliptic blending equation. The predictions of turbulent heat transfer in a plane channel flow have been carried out with constant wall heat flux and constant wall temperature difference boundary conditions respectively. Also, the rotating channel flow with constant wall temperature difference is considered to test the applicability of the model. The prediction results show that the distributions of the turbulent heat fluxes and mean temperature are well captured by the present algebraic heat flux model.
4,000원
17.
2015.02
구독 인증기관 무료, 개인회원 유료
Based on the attitude of science discovery, an industrial induction motor silencer is designed and developed, and the performance of this silencer is evaluated experimentally in this paper. The basic principle of the silencer was used as the parabola principle. During the experiment, the performance of the proposed silencer is preliminary researched using software simulation method, test analogy method, and some other methods to infer experiment was conducted to evaluate the experiment. During the simulation experiment, 25dB level can be reduced in the 12,500∼16,000Hz range. More than 35dB level was reduced in the 2,500∼5,000Hz range. When we used the silencer, the noise in the high frequency bands above 1,000Hz are reduced. In particular, 1,600Hz band is greatly reduced on average by 5dB. Some effective conclusions are obtained from the analysis of the experiment results, despite some uncertain factors in the experiment
4,000원
18.
2015.02
구독 인증기관 무료, 개인회원 유료
In this paper, the gait parameter detection system using an infrared rays elements was developed. This system consist of the transmission unit and receiver of an infrared LED light and the gait parameter were calculated by the non-transmission timing of infrared LED light from user’s leg movement Based on this method, we calculated the velocity of gait and gait stride of the person during the gait motion on the treadmill. To confirm the effectiveness of this system, we analyzed the real velocity of the treadmill using tachometer on treadmill compared with controlled velocity of treadmill.
4,000원
19.
2015.02
구독 인증기관 무료, 개인회원 유료
This paper is concerned with the quality assurance of recliner chair frame. It is necessary for recliner chair frame that is endurable for the repeated load and sudden impact of human sitting and general use. And this paper studies the quality assurance of recliner chair frame that is newly designed and made in the regional company. The procedures of quality assurance are composed of the stress analysis using computer simulation and results by test equipments. Theoretical survey is composed with the stress analysis results from ANSYS program and quality assurance procedures are composed of static load test, reciprocal load test of spring and impact test of locking frame. The results from the mechanical tests satisfy the safety criteria of the Korean national standard. This research assures the quality of new designed recliner chair frame and can be used as quality assurance procedures of concerned structures
4,000원
20.
2015.02
구독 인증기관 무료, 개인회원 유료
This study investigates the wear degree of the shock absorber at the artificial knee joint due to bending degree of knee. As the stress distribution due to this angle is understood when the knee is bent, it can be shown how much and which configuration the wear of the shock absorber progresses in. On the basis of the analysis result, the stress applied at the shock absorber becomes higher and the equivalent stress becomes higher as the bending angle of knee is increased. The walking habit as the right attitude can be examined by applying the general joint as well as the artificial knee joint by using this study result
4,000원
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