한국기계기술학회지 [Journal of the Korean Society of Mechanical Technology]

간행물 정보
  • 자료유형
  • 발행기관
    한국기계기술학회 [Korean Society of Mechanical Technology]
  • ISSN
  • 간기
  • 수록기간
  • 등재여부
    KCI 등재
  • 주제분류
    공학 > 기계공학
  • 십진분류
    KDC 550 DDC 621
제13권 제2호 (21건)



탄소섬유강화플라스틱의 적층구성에 따른 드릴 가공에 관한연구

김선범, 신형곤, 김태영

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.1-7

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The CFRP composite has a lot of merits such as mechanical characteristic, light and thermal resistance. For these merits, CFRP is applied to so many industrial area. In order to use the composite materials in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joints must be provided, which require precise ,machining. In this study, the specimens differentiating the stacking sequence of 5kinds were used. When drilling the carbon fiber reinforced plastics, it was checked on whether the stacking sequence reached any effect on the cutting force. Also relationship between the drill diameter is examined from the drilling experiment, which is the drilling of Fabric, Unidirectional specimen with ∅6mm, ∅10mm, ∅12mm cemented carbide drill. Considering cutting force and drilling diameter, the results are analyzed.



여객선 기관실의 설계 옵션 평가를 위한 결정 지원 프레임 워크


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.9-19

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Most real world design evaluation and risk-based decision support combine quantitative and qualitative (linguistic) variables. Decision making based on conventional mathematics that combines qualitative and quantitative concepts always exhibit difficulty in modelling actual problems. The successful selection process for choosing a design/procurement proposal is based on a high degree of technical integrity, safety levels and low costs in construction, corrective measures, maintenance, operation, inspection and preventive measures. In this paper, a design decision support framework using a composite structure methodology grounded in approximate reasoning approach and evidential reasoning method is suggested for design evaluation of machinery space of a ship engine room at the initial stages. An illustrative example is used to demonstrate the application of the proposed framework.



여객선의 공식 화재안전 평가 : 비용-이득 및 의사결정 평가


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.21-29

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This paper examines the applicability of formal safety assessment to the passenger ships. This is followed by an analysis of passenger ship characteristics and a proposed formal safety assessment methodology. Five interlocking steps are described to construct a safety model including novel risk assessment, cost-benefit analysis and decision-making approaches. A case study is carried out in order to demonstrate the proposed methodology. Further development in formal safety assessment in the context of passenger ship safety is finally discussed in detail.



박판 Al 2024-T3 합금재료의 피로균열성장지연거동과 피로수명예측


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.31-37

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Sheet aluminum alloys have been used in manufacturing of machine structures. In fatigue crack propagation behavior of thin sheet aluminum alloys, it is important that fatigue crack growth rate is affected by crack closure phenomenon. In this work, we analyzed the characteristics of fatigue crack propagation behavior in experiment of constant stress condition for thin sheet Al 2024-T3 alloys, and identified the retardation behavior of crack growth by comparing experimental results of thin and thick plate specimen. We attempt to operate the fatigue life estimating process using the fatigue related material constants from referred fatigue crack propagation analysis. And we analyzed the experimental and prediction results of fatigue life of thin sheet aluminum alloy in order to identify the relation between retardation behavior of fatigue crack growth and crack closure phenomenon.



평판 상에서 경사 분류열 부근의 유동에 대한 실험적 연구


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.39-44

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An experimental method, based upon wall visualizations, has been developed to observe air flow near a plane wall around a row of five 45° inclined jets discharging into a cross stream. This study concerns the variation of injection rate R which is one of the most important parameters governing this flow type. The Results are concentrated on the spatial evolution of two lobes with R. These structures are fastened to jets downstream edge and exist for very low injection rate values which are an indication of jets takeoff at the immediate downstream of injection orifices. The velocity rate of 0.42 marks a change in the structure alimentation system.



비선형 차량능동현가시스템의 주파수 감응감쇠 특성연구


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.45-54

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A vehicle suspension system performs two functions, the ride quality and the stability, which conflict with each other. Among the various suspension systems, an active suspension system has an external energy source, from which energy is always supplied to the system for continuous control of vehicle motion. In the process of the linearization for the nonlinear active suspension system, the frequency dependent damping method is used for the exact modelling to the real model. The pressure control valve which is controlled by proportional solenoid is the most important component in the active suspension system. The pressure control valve has the dynamic characteristics with 1st order delay. Therefore, It's necessary to adopt the lead compensator to compensate the dynamics of the pressure control valve. The sampling time is also important factor for the control performances. The sampling time value is proposed to satisfy the system performances. After the modelling and simulation for the pressure control valve and vehicle dynamic, the performances of the vehicle ride quality and the stability are enhanced.



강제 재생 방식 DPF 내부의 온도 분포 특성에 관한 수치해석

박성천, 이한성

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.55-61

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This study analyzed on the characteristics of temperature distribution in an active regeneration DPF using computer simulation. In order to verify the boundary condition of analysis, results of temperature distribution in DPF are compared between experimental and computer simulation. Using this boundary condition, temperature distribution and filter's durability in DPF analyzed according to various operating conditions. The results of computational analysis are agreed well with experimental ones from the tendency of temperature distribution of axis and radius direction. The temperature increases and the axial temperature gradients in DPF according to velocity of exhaust gas are lowered as the high velocity of exhaust gas. But the temperature gradients of radius direction at exit side in DPF are grown as the high velocity of exhaust gas. The results according to inlet temperature of exhaust gas show that the increase ratios of temperature in DPF are grown as the high temperature of exhaust gas.



지역난방 에너지 공동주택의 다중 열공급 제어 알고리즘 개발에 관한 해석적 연구

변재기, 최영돈, 박명호, 신종근

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.63-70

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In the present study, we developed optimal heat supply algorithm which minimizes the heat loss through the distribution pipe line in group energy apartment. Heating load variation of group energy apartment building in accordance with outdoor air temperature was predicted by the correlation obtained from calorimeter measurements of whole households of apartment building. Supply water temperature and mass flow rate were conjugately controlled to minimize the heat loss rate through distribution pipe line. Group heating apartment located in Hwaseong city, Korea, which has 1,473 households divided in 4 regions, was selected as the object apartment for verifying the present heat supply control algorithm. Compared to the original heat supply system, 10.4% heat loss rate reduction can be accomplished by employing the present control algorithm.



4륜 거동 측정에 의한 카트 프레임의 비틀림특성 분석

김용호, 유충준

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.71-78

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A kart is a vehicle without the suspension system and the differential gear. The kart frame as an elastic body plays the role of a spring. By the cornering of a kart, rolling, pitching and twisting motions are induced in the kart frame. Also the slip or noncontact of the wheel and a permanent deformation of the kart frame can be induced. In order to examine closely this phenomenon, measurement on height-displacements with various sensors and tracking system and analysis on the kart frame twisting characteristics with the rolling and pitching angle are needed. According to the measurement result, while driving in a curve at high speed the kart frame is quite twisted. Analysis on the measurement results shows that a kart used primarily in high speed requires a frame with low torsional stiffness and a frame material with high tensile strength and large elongation.



6속 자동변속기 밸브바디의 윤활오일유량 분배 특성 연구

김진용, 나병철, 이계철

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.79-84

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In general, a valve body of the automatic transmission(AT) is controlled by the clutch, the brake and lubricating oil flow in a hydraulic system and lubricant flow for each valve can be adjusted independently. To increase the lifetime of AT, the lubrication flow rate in a valve body for a 6 speed AT based parallel hybrid electric vehicle must be provided with proper oil distribution and control. In this study, we carried out several experiments without the inner parts of AT and with a AT assembly. The variation of the flow rate on oil temperature and pressure between an oil supply port and the outlets of the lubrication port was evaluated and analyzed. In the case of AT without the inner parts, it was evident that as the oil required for an operation of the clutch and brake was discharged from the outlet port, the flow rate from each lubrication port is decreased. However, the flow rate of the AT assembly was slightly increased. In addition, the lubrication flow rate was increased with increasing the oil temperature, and also it was reduced with increasing the oil pressure. Details of the resulting data are discussed.



환상 파이프 내에서의 의소성 유체를 이용한 열전달 향상에 관한 연구


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.85-91

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Computational results with pseudoplastic fluid flows for fully developed non-Newtonian laminar flows have been obtained. Those consist of the product of friction factor and Modified Reynolds number and Nusselt numbers with respect to the shear rate parameter in an annular pipe. The numerical results of the product of friction factor and Reynolds numbers and the Nusselt numbers for both Newtonian region and the power law region were compared with previously published asymptotic results, respectively. In the present calculations, the product of friction factor and Newtonian Reynolds numbers for pseudoplastic fluid at power law region in annular pipe is 180% less than that for Newtonian fluid. For power law fluids with different power law flow indices, the difference of the product of friction factor and power law Reynolds number between previous and the present results at the power law region is within 0.20%. The solutions also show the effect of the shear rate parameter on the Nusselt number and about 11% increase of Nusselt number at the power region.



음향방출법에 의한 SM45C 고주파 열처리 강의 기계적 특성 평가


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.93-100

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This study deals with the high frequency induction hardening (HF at 850℃, 120kHz & 50kW condition) SM45C steel. (1) The HF specimen, which was tempered at 150℃, did not show any tempering effect. A brittle fracture occurred at rounded area of the tensile specimen. AE (acoustic emission) amplitude distribution showed between 45dB and 60dB. (2) A slip and fracture occurred at the hole area of the HF specimen which was tempered at 300℃. As they pass the yield point, the AE energy is increased intermittently and AE amplitude distribution exists between 70dB and 85dB. In addition, after imposing the maximum tensile load, AE signals showed high amplitude and energy distribution. The AE amplitude showed between 45dB and 70dB. (3) A brittle fracture occurred at HF specimen which was tempered at 450℃ as if it is torn in the direction of 45° on parallel area over the both sides of the tensile specimen, which lead to several peak appeared in AE energy. It was found that the AE amplitude was relatively low and the AE energy was high.



모서리 형상에 따른 수직벽 후류특성에 관한 연구

이철재, 조대환

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.101-106

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In this study, the velocity distribution according to upper side coner shape of underwater construction with rectangular cylinder was measured with PIV method and the wake flow characteristics was considered. According to the coner shape, the flow pattern of wake flow was also differed greatly and the step-shaped coner of cut-off ratio B/H=0.06 was similar in the slope shape in result.



히스토그램에 의한 작업장노출한계 추정에 관한 연구

이철재, 조대환

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.107-113

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This study was performed for the application of the exposure limit in work field and the relative noxious gas concentration was estimated by using a miniature ship. The noxious gas concentration about light and shade number distribution of measuring subject field was estimated by using floating visualization image from a miniature ship in a large wind tunnel. About the concentration estimation, the correlation of concentration distribution drawn from the existing experimental results was used, the estimation result satisfied LTEL standard.



Cr-Mo강의 수소확산 특성에 관한 유한요소해석

이휘원, 하민수

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.115-121

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The size of hydrogen molecule is not so small as to invade into the lattice of material, and therefore, hydrogen invades into the material as atom. Hydrogen movement is done by diffusion or dislocation movement in the near crack tip or plastic deformation. Hydrogen appeared to have many effects on the mechanical properties of the Cr-Mo steel alloys. The materials for this study are 1.25Cr-0.5Mo and 2.25Cr-1Mo steels used at high temperature and pressure. The hydrogen amount obtained by theoretical calculation was almost same with the result solved by finite element analysis. The distribution of hydrogen concentration and average concentration was calculated for a flat specimen. Also, finite element analysis was employed to simulate the redistribution of hydrogen due to stress gradient. The calculation of hydrogen concentration diffused into the material by finite element method will provide the basis for the prediction of delayed fracture of notched specimen. The distribution of hydrogen concentration invaded into the smooth and notched specimen was obtained by finite element analysis. The hydrogen amount is much in smooth specimen and tends to concentrate in the vicinity of surface. Hydrogen embrittlement susceptibility of notched specimen after hydrogen charging is more remarkable than that of smooth specimen.



신 촉매를 이용한 DME 전환율에 관한 연구


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.123-128

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It has been stand high in estimation to converse from Carbon dioxide to Dimethyl Ether in new alternative fuel energy division in 21C, especially Using of DME in point of view of transportation fuel has been discussed of a new clean energy which is very lower of exhaust gas than gasoline and diesel energy. In this paper it is used ZSM-5 and I developed new catalyst by addition of cerium to control acidity. The new catalyst was proved high conversion rate, when it was conversed from methanol to DME, there wasn't any additional material except DME and water, and I overlooked reaction temperature, reaction time, amount of catalyst, amount of added cerium, effect of water content in methanol, reaction temperature by making change of reaction time. I have conclude that conversion rate to DME was increased as increased of catalyst amounts. The best catalyst condition of without additional product was treated poisoning from ZSM-5 to 5% cerium and new catalyst was not effected in purity of fuel methanol.




볼 형태 가동플랜지를 갖는 건식 무단변속기에 관한 실험적 연구

정상훈, 이한성, 함성훈, 권영웅

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.129-135

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Dry CVT(Continuously variable transmission) consists of a driving pulley and a driven pulley joined by rubber V-belt. Each pulley consists of a fixed flange and a movable flange. The movable flange of the driving pulley has the centrifugal roller and a ramp plate in the flange. The movable flange moves toward a fixed flange under the actuation of a centrifugal roller, as the driving pulley speed increases. The main advantages of the Dry CVT with V-belt, which has been popular in Asia, are a simple mechanism, less maintenance and low cost. The important claim which have an influence on the performance of the Dry CVT is the wear of the centrifugal roller. In this study ball type is proposed instead of roller type of movable flange to resolve claim. Also experiments are carried out for new model to evaluate performances.



고압용기의 계장선 통과부위 밀봉기술 개발

정황영, 홍진태, 안성호, 정창용, 이종민, 이철용

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.137-143

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Fuel Test Loop(FTL) is a facility which could conduct a fuel irradiation test at HANARO (High-flux Advanced Neutron Application Reactor). FTL simulates commercial NPP’s operating conditions such as the pressure, temperature and neutron flux levels to conduct the irradiation and thermo- hydraulic tests. The In-Pile Test Section(IPS) installed in HANARO FTL is designed as a pressure vessel design conditions of 350℃, 17.5MPa. The instrumentation MI-cables for thermocouples, SPND and LVDT are passed through the sealing plug, which is in the pressure boundary region and is a part of instrumentation feedthrough of MI-cable. In this study, the brazing method and performance test results are introduced to the sealing plug with BNi-2 filler metal, which is selected with consideration of the compatibility for the coolant. The performance was verified through the insulation resistance test, hydrostatic test, and helium leak test.



하나로에서의 고온재료 조사장치 개발

조만순, 주기남

한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.145-153

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The irradiation tests of materials in HANARO have been performed usually at temperatures below 300℃ at which the RPV(Reactor Pressure Vessel) materials of the commercial reactors such as the light water reactor and CANDU are operated. As VHTR(Very High Temperature Reactor) and SFR (Sodium-cooled Fast Reactor) projects are being carried as a part of the present Gen-IV program in Korea, the requirements for irradiation of materials at temperatures higher than 500℃ are recently being gradually increased. To overcome the restriction in the use at high temperature of the existing Al thermal media, a new capsule with double thermal media composed of two kinds of materials such as Al-Ti and Al- graphite was designed and fabricated more advanced than the single thermal media capsule. At the irradiation test of the capsule, the temperature of the specimens successfully reached 700℃ and the integrity of Al, Ti and graphite material was maintained.



고강도강을 이용한 평판형 승용차 서스펜션 크로스 멤버의 성형


한국기계기술학회 한국기계기술학회지 제13권 제2호 2011.06 pp.155-163

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The flat type automotive cross members with high strength steel have advantages in light weight and fewer parts compared to the hump type cross members. But the complex part shape of the flat type cross member and the poor formability of high strength steel make it difficult to form the parts without forming defects, such as splits and wrinkles. The purpose of this study is to develop the flat type automotive cross member with high strength steel. For that purpose, drawing processes are evaluated using PAM-STAMPTM and proper draw die and blank designs are proposed. Using the proposed die and blank design, the flat type upper and lower cross member could be formed successfully without forming defects.


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