• 제목, 요약, 키워드: Performance test load

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Performance of Rock-socketed Drilled Shafts in Deep Soft Clay Deposits

  • Kim, Myung-Hak
    • 한국지반공학회:학술대회논문집
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    • pp.409-429
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    • 2006
  • In designing rock-socketed drilled shaft, bearing capacity evaluation is very important because the maximum values of base and side resistance are not generally mobilized at the same value of displacement, FHWA and AASHTO code suggest different ultimate bearing capacity formular according to rock type and shaft settlement. In domestic code suggest base resistance and side resistance can be added on condition that after confirming the result of field load test with axial load transfer test. This paper shows that static load test and hi-directional load test result analysis of deep rock-socketed drilled shaft in three different sites. Load-settlement curve, t-z, and q-w curve in rock-socketed part were calculated and compared. t-z curve in weathered and soft rock showed no deflection softening behavior in pretty large strain (about 2-3% of diameter). Ultimate resistance could be the summation of side resistance and base resistance in rock-socketed drilled shaft in domestic sites.

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모터 부하시험을 위한 부하인가 장치 개발 (Development of Load apparatus for Motor)

  • 임병주;박창대
    • 한국유체기계학회 논문집
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    • v.12 no.6
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    • pp.26-32
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    • 2009
  • We have constructed loading apparatuses to electrical motor with a powder brake and a oil pump for load test of a several ten kilowatt-motor and performed load test with two motors. On operating the loading apparatus with a oil pump, temperature of the oil may excessively increase and fail to operate due to dynamic energy loss of equipment in oil loop. In order to control the oil temperature, factors of the energy loss were analyzed and the quantitative loss was calculated. Load tests of motors with two loading apparatuses constructed were successfully performed and strengths of each apparatus come out on operating.

통신 항법용 다중대역 안테나 내장 스킨구조의 지상시험평가 (Ground Test & Evaluation of Conformal Load-bearing Antenna Structure for Communication and Navigation)

  • 김민성;박찬익;조창민;전승문
    • 한국항공우주학회지
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    • v.41 no.11
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    • pp.891-899
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    • 2013
  • 본 논문에서는 전투기 주구조물에 적용할 수 있는 안테나 내장 스킨구조(CLAS)의 새로운 시험평가 절차를 제시하였다. 대수 주기 패치형 안테나를 통신항법용 다중대역 안테나로 설계하였다. 탄소/유리 섬유 강화 적층 복합재(CFRP/GFRP)를 공력하중을 지지하기 위한 구조로 사용하고 안테나 성능 향상을 위해 하니컴 층을 적층하였다. 여러 재질로 구성된 다층구조의 안테나 내장 스킨구조를 고온의 오븐에서 경화하였다. 내장된 안테나의 이득, 전압 정재파비, 방사패턴을 0.15GHz~2GHz 주파수 범위에서 무반향 챔버시설을 이용하여 측정하였다. 안테나 내장 스킨구조의 구조강도를 평가하기 위하여 인장, 전단, 피로, 충격 하중을 부가하는 구조시험을 수행하였다. 각각의 구조시험 후에 안테나 성능시험을 수행하여 초기 값과 비교하므로써 구조시험이 안테나에 미치는 영향을 확인하였다. 새로 개발한 안테나 내장 스킨구조 시험평가 절차를 통신항법용 CLAS에 적용하여 설계개선이 필요한 점을 발견하였다.

Seismic Performance and Retrofit of Circular Bridge Piers with Spliced Longitudinal Steel

  • Chung, Young-Soo;Lee, Jae-Hyung
    • KCI Concrete Journal
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    • v.14 no.3
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    • pp.130-137
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    • 2002
  • It is known that lap splice in the longitudinal reinforcement of reinforced concrete(RC) bridge columns is not desirable for seismic performance, but it is sometimes unavoidable. Lap splices were practically located in the potential plastic hinge region of most bridge columns that were constructed before the adoption of the seismic design provision of Korea Bridge Design Specification on 1992. The objective of this research is to evaluate the seismic performance of reinforced concrete(RC) bridge piers with lap splicing of longitudinal reinforcement in the plastic hinge region, to develop the enhancement scheme of their seismic capacity by retrofitting with glassfiber sheets, and to develop appropriate limited ductility design concept in low or moderate seismicity region. Nine test specimens in the aspect ratio of 4 were made with three confinement ratios and three types of lap splice. Quasi-static test was conducted in a displacement-controlled way under three different axial load levels. A significant reduction of displacement ductility ratios was observed for test columns with lap splices of longitudinal steels.

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자전거 프레임의 소재 및 종류에 따른 피로특성 (Fatigue Characteristics of Bicycle Frames Depending on Types and Materials)

  • 권경배;정성균
    • 한국안전학회지
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    • v.32 no.5
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    • pp.8-12
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    • 2017
  • Bicycles are very popular sporting goods in these days. Thus, the durability of bicycles is very important for the safety of bicyclists. It is well known that a bicycle frame is a major component which is essential to the safety and performance of a complete bicycle. In this study, the durability of bicycle frames were experimentally investigated under the fatigue load. Eighty bicycle frames with different types and materials were prepared and tested according to EN standards. Three kinds of fatigue loads, that is, pedalling, vertical and horizontal fatigue load, which occur constantly during riding a bicycle, were applied to the bicycle frames. The experimental results show that the horizontal fatigue load was the severest mode to pass EN standard. The pass ratio of horizontal fatigue load test was 45.2%, while the pass ratio of vertical fatigue load test was 100%. Most of cracks were found at the right side of bottom bracket shell and at the intersection area between head tube and down tube. It seems that the experimental results can be applied to improve the safety and performance of a bicycle frame.

HEV용 e-4WD 구동을 위한 매입형 영구자석 동기전동기의 특성해석 및 시험 (Characteristic Analysis and Test of IPMSM for e-4WD of the Hybrid Electric Vehicle)

  • 정수진;이주
    • 전기학회논문지
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    • v.65 no.5
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    • pp.777-784
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    • 2016
  • In this paper, the performance design and analysis for an Interior Permanent-Magnet Synchronous Motor (IPMSM) that will be used as a traction motor in the e-4WD system of hybrid SUV(Sports Utility Vehicle) and RV(Recreational Vehicle), are investigated using finite element method. In order to improve the accuracy of design, the tolerances of parts and assemblies as well as the material properties of permanent magnet, stator, rotor and winding etc. are considered under the conditions similar to real driving state of motor. Both no load performance test and maximum load performance test, in which real driving state and cooling condition have been considered, are also implemented via proto sample build to verify the validity of motor's performance design.

An experimental study on fire resistance of medical modular block

  • Kim, Hyung-Jun;Lee, Jae-Sung;Kim, Heung-Youl;Cho, Bong-Ho;Xi, Yunping;Kwon, Ki-Hyuck
    • Steel and Composite Structures
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    • v.15 no.1
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    • pp.103-130
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    • 2013
  • Fire performance and fire safety of high-rise buildings have become major concerns after the disasters of World Trade Center in the U.S. in 2001 and Windsor tower in Spain in 2005. Performance based design (PBD) approaches have been considered as a better method for fire resistance design of structures because it is capable of incorporating test results of most recent fire resistance technologies. However, there is a difficulty to evaluate fireproof performance of large structures, which have multiple structural members such as columns, slabs, and walls. The difficulty is mainly due to the limitation in the testing equipment, such as size of furnace that can be used to carry out fire tests with existing criteria like ISO 834, BS 476, and KS F 2257. In the present research, a large scale calorie meter (10 MW) was used to conduct three full scale fire tests on medical modular blocks. Average fire load of 13.99 $kg/m^2$ was used in the first test. In the second test, the weighting coefficient of 3.5 (the fire load of 50 $kg/m^2$) was used to simulate the worst fire scenario. The flashover of the medical modular block occurred at 62 minutes in the first test and 12 minutes in the second test. The heat resistance capacity of the external wall, the temperatures and deformations of the structural members satisfied the requirements of fire resistance performance of 90 minutes burning period. The total heat loads and the heat values for each test are calculated by theoretical equations. The duration of burning was predicted. The predicted results were compared with the test results, and they agree quite well.

시뮬레이터 컨버터에 의한 인버터 성능시험에 관한 연구 (A Study on the Inverter performance test by Simulated Converter)

  • 조정민;함년근;김대균;이상집;김성남;이훈구;한경희
    • 전력전자학회:학술대회논문집
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    • pp.765-768
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    • 2003
  • In the end of a production line a new built power converter has to undergo a series of stress tests. This can be achieved by connecting it to a dynamometer consisting of a three-phase machine joined by a rigid shaft to a DC load machine. The latter is controlled to create some specific load characteristic needed for the test. In this paper a test method is proposed, in which no mechanical equipment is needed. The suggested test stand consists only of a converter to be tested and a simulator converter. Both devices are connected back-to-back on the AC-side via smoothing reactors. The simulator operates in real-time as an equivalent load circuit, so that the device under test will only notice the behaviour of a three-phase machine under consideration of the load.

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판토그라프 접촉력 측정을 위한 스트레인 게이지 내장형 센서 개발 (Development of Load Cell to Measure Contact Force of Pantograph)

  • 박찬경;백진성;김영국;김기환
    • 한국철도학회:학술대회논문집
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    • pp.947-953
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    • 2010
  • The KTX-Sancheon has been commercially operating on the high-speed line since March. 2. In order to verify the performance of high-speed train and core equipments such as current collection system, sophisticated tests and evaluating procedures should have been considering. In this paper, the load cell with a built-in strain-gauge which developed to improve measuring method of contact force between the pantograph and catenary system is introduced. The static test results of the load cell shows that its design is very suitable and applicable for the dynamic test and on-line test. After the test and evaluation of load cell's dynamic calibration with pantograph, we will be applied to test interaction characteristics between the pantograph and catenary system on the high-speed line.

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Evaluation of Field Calibration Test on Rail for Train Wheel Force Measurement

  • Sim, Hyoung-Bo;Yeo, Inho
    • International Journal of Railway
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    • v.8 no.1
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    • pp.1-4
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    • 2015
  • An accurate measurement of the train-track interaction forces is important for track performance evaluation. In the field calibration test as a wheel load measurement process, the calibration system creates a different boundary condition in comparison with that in the train wheel passage. This study aims to evaluate a reliability of the field calibration test in the process of wheel load measurement. Finite element models were developed to compare the deformed shapes, bending moment and shear force profiles on the rail section. The analysis results revealed that the deformed shapes and their associated bending moment profiles on the rail are significantly different in two numerical simulations of the calibration test and the train wheel load passage. However, the shear stress profile on the rail section of the strain gauge installation in the field was almost identical, which may imply that the current calibration test is sufficiently reliable.