• 제목/요약/키워드: Load characteristics design

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공기윤활 범프 저어널 베어링의 부상 특성에 관한 연구 (A Study on the Lift-off Characteristics of an Air-lubricated Bump Foil Journal Bearing)

  • 이남수;이용복;최동훈;김창호
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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    • pp.236-242
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    • 2001
  • In this paper the effect of bump compliance, load, and the number of pad on the lift-off speed is studied. When the load is greater and bump compliance lower, the shaft is lifted off at higher rotating speed. And when the load is applied near the center of pad, lift-off speed is lower. When the number of pad increases, the lift-off speed is higher. The lift-off characteristics can be used to lengthen the life time of the coating and design the rotating machinery supported by bump bearings.

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암반에 근입된 SIP 말뚝의 지지력 특성에 관한 연구 (A Study on the Characteristics of Bearing Capacity for SIP Piles constructed on Rock Mass)

  • 김태훈;박준홍;이송
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 춘계학술대회 논문집
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    • pp.295-300
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    • 2002
  • In this research problems of recent design methods and their improvement for SIP in domestic areas were studied by using the characteristics of load-settlement curves and bearing capacity from field loading tests. Elastic and plastic settlement for total settlement in each loading step conducted domestic areas had a tendency. From these tendency and bearing capacity determined by loading tests we can ascertain that empirical chart can be assistant tool in SIP design. It showes that SIP design using N-value in domestic area with soil condition of grarute type results in very conservative bearing capacity, to be opposed in soil with unprofitable geological condition the design can be insecure. Also, we can ascertain that Meyerhof's bearing capacity used modified N-value on tip part of pile is more applicable than recent design method where tip bearing capacity is 20NAp N-value limited to 50. These results show that modified design method can he more economic than before because of using pile's bearing capacity to tolerable load of pile material.

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Strut-tie model for two-span continuous RC deep beams

  • Chae, H.S.;Yun, Y.M.
    • Computers and Concrete
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    • 제16권3호
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    • pp.357-380
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    • 2015
  • In this study, a simple indeterminate strut-tie model which reflects complicated characteristics of the ultimate structural behavior of continuous reinforced concrete deep beams was proposed. In addition, the load distribution ratio, defined as the fraction of applied load transferred by a vertical tie of truss load transfer mechanism, was proposed to help structural designers perform the analysis and design of continuous reinforced concrete deep beams by using the strut-tie model approaches of current design codes. In the determination of the load distribution ratio, a concept of balanced shear reinforcement ratio requiring a simultaneous failure of inclined concrete strut and vertical steel tie was introduced to ensure the ductile shear failure of reinforced concrete deep beams, and the primary design variables including the shear span-to-effective depth ratio, flexural reinforcement ratio, and compressive strength of concrete were reflected upon. To verify the appropriateness of the present study, the ultimate strength of 58 continuous reinforced concrete deep beams tested to shear failure was evaluated by the ACI 318M-11's strut-tie model approach associated with the presented indeterminate strut-tie model and load distribution ratio. The ultimate strength of the continuous deep beams was also estimated by the experimental shear equations, conventional design codes that were based on experimental and theoretical shear strength models, and current strut-tie model design codes. The validity of the proposed strut-tie model and load distribution ratio was examined through the comparison of the strength analysis results classified according to the primary design variables. The present study associated with the indeterminate strut-tie model and load distribution ratio evaluated the ultimate strength of the continuous deep beams fairly well compared with those by other approaches. In addition, the present approach reflected the effects of the primary design variables on the ultimate strength of the continuous deep beams consistently and reasonably. The present study may provide an opportunity to help structural designers conduct the rational and practical strut-tie model design of continuous deep beams.

유압실린더내 정압베어링의 특성에 관한 연구 (A Study on the Characteristic of the Hydrostatic Bearing in the Hydraulic Cylinder)

  • 강형선
    • Journal of Advanced Marine Engineering and Technology
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    • 제32권4호
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    • pp.522-527
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    • 2008
  • On designing of hydrostatic bearing, load, quantity of oil, stiffness and friction load are considered as basic characteristics. For the analysis of these basic characteristics, pressure distribution by oil film is obtained. Speed of piston, clearance, leakage of oil, eccentricity, shape and roughness of bearing affect the results which are the analysis of basic characteristics of load, quantity of oil, stiffness and friction load. The relationship among those factors are required for optimum designing of hydrostatic bearing for machining tool. Reynold's Equation is calculated through finite element method. Load, leakage of quantity and pressure distribution as variation of length, land length ratio, eccentricity and axial velocity of bearing are investigated. Then optimum design variables are obtained.

Large-scale pilot test study on bearing capacity of sea-crossing bridge main pier pile foundations

  • Zhang, Xuefeng;Li, Qingning;Ma, Ye;Zhang, Xiaojiang;Yang, Shizhao
    • Geomechanics and Engineering
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    • 제7권2호
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    • pp.201-212
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    • 2014
  • Due to the sea-crossing bridge span is generally large and main pier pile foundations are located in deep water and carry large vertical load, sea-crossing bridge main pier pile foundations bearing mechanism and load deformation characteristics are still vague. Authors studied the vertical bearing properties of sea-crossing bridge main pier pile foundations through pilot load tests. Large tonnage load test of Qingdao Bay Bridge main pier pile program is designed by using per-stressed technique to optimize the design of anchor pile reaction beam system. Test results show that the design is feasible and effective. This method can directly test bearing capacity of main pier pile foundations, and analysis bearing behaviors from test results of sensors which embedded in the pile. Through test study the vertical bearing properties of main pier pile foundation and compared with the generally short pile, author summarized the main pier pile foundations vertical bearing capacity and the main problem of design and construction which need to pay attention, and provide a reliable basis and experience for sea-crossing bridge main pier pile foundations design and construction.

다양한 링크구동 기계프레스에 대한 기구학적 분석 (Kinematic Analysis of Several Linkage Drives for Mechanical Presses)

  • 구형욱;황병복;임중연;이호용
    • 소성∙가공
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    • 제6권6호
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    • pp.471-481
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    • 1997
  • This paper is concerned with the kinematic analysis of several linkage drives for mechanical presses. Load and velocity characteristics of conventional presses are illustrated and a design of new drive for a mechanical press is represented. In this regard, a crank-slider mechanism with arc crank-pin guide is introduced and compared with other linkage drives. Kinematic performances are analyzed in respect of load capacity, slide velocity characteristics using a developed SS-Plot program. The new linkage drive turns out to be effective in terms of load and velocity characteristics, and productivity.

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Beam형(形) Load Cell의 FEM Simulation과 그 전기적특성(電氣的特性) (Electrical Characteristics and FEM Simulations of Beam Type Load Cell)

  • 박찬원;안광희;최규석
    • 산업기술연구
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    • 제12권
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    • pp.25-36
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    • 1992
  • In this paper, we simulate and calculate the stress and output voltage of the beam structure load cells by using FEM as varing physical structure parameters and loading positions. It is proved that stress enhance as the increase of the notch pitch and radius of the load cell, but decrease as the increase of the notch thickness and beam width. The results are good matched for basic formulas of the single fixed beam, and are verified our simulation is correct. Also, it is found that the stress characteristics of the load cell is varied according to loading positions with structure parameters, and caculated output voltage of the load cell approximate to those of the real manufactured ones. As a result, this study will offer efficient design and analysis technique for making special and variety capacity of load cells.

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우편집중국 수변전 설비 수용률 산정을 위한 새로운 부하 계산법 개발 (Development of a Novel Load Capacity Estimation Method for Demand Factor Calculation of a Mail Center)

  • 윤순만;정종찬;김광호
    • 산업기술연구
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    • 제30권A호
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    • pp.3-8
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    • 2010
  • Recently, There have been many attempts to optimize energy usage in buildings and houses using Information Technology(IT) and the typical implementation can be found in Intelligent Building and Zero Energy Building. These kinds of buildings need to forecast the building loads, estimate the capacity requirement for power supply, and decide the capacity of the main transformer of the building. Currently, the capacity of the main transformer has been decided just using typical load estimation method not considering the load characteristics and patterns. In this paper, we propose a new load estimation method considering the load characteristics and patterns of the builiding. The proposed method was applied to actual mail center and verified the feasibility of application to actual design of buildings.

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자동차 헬리컬기어의 하중전달 특성해석 (Analysis of Load Transmission Characteristics for Automobile Helical Gear)

  • 박찬일;이장무
    • 한국자동차공학회논문집
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    • 제3권5호
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    • pp.1-9
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    • 1995
  • The purpose of this study is to develop a computer simulation program for analyzing load transmission characteristics of a helical gear system in design stage. In this analysis, the rotational delay, load distribution, root stress, and contact area are investigated. That is, the influence function of deflection is obtained by finite element analysis and the influence function of approach and gear tooth error are considered. Load distribution, rotational delay, and contact area are calculated by solving load-deflection equation which includes these influence functions and tooth error, and the influence function of the bending moment is obtained by finite element analysis. The root stress is calculated by the load distribution and the influence function of the bending moment. The results of the simulation are cross-checked through a specially designed experimental set-up.

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석영 가열램프의 열 유속 특성 파악을 통한 고온 구조시험의 열 하중 설계에 관한 연구 (A Study on Heat Flux Characteristics of Tubular Quartz Lamp for Thermal Load Design of High Temperature Structural Test)

  • 김준혁
    • 한국군사과학기술학회지
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    • 제25권4호
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    • pp.355-363
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    • 2022
  • Development of supersonic flying vehicle is one of the most latest issue in modern military technology. Specifically, structural integrity of supersonic flying vehicle can be verified by high temperature structural test. High temperature structural test is required to consider thermal load caused by aerodynamic heating while applying structural load simultaneously. Tubular quartz lamps are generally used to generate thermal load by emitting infrared radiation. In this study, modified heat flux model of tubular quartz lamp is proposed based on existing model. Parameters of the proposed model are optimized upon measured heat flux in three dimensions. Finally, thermal load of plate specimen is designed by the heat flux model. In conclusion, it is possible to predict heat flux applied on plate specimen and desired thermal load of high temperature structural test can be obtained.