• Title/Summary/Keyword: Test Load

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A study on case analysis for loading capacity standard establishment of bi-directional pile load test (BD PLT) (양방향말뚝재하시험의 재하용량 기준 설정을 위한 사례분석 연구)

  • Choi, Yong-Kyu;Seo, Jeong-Hae;Kim, Sang-Il
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.377-384
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    • 2008
  • In the bi-directional pile load test (BD PLT) for pile load test of Mega foundation, loading capacity specification were not specified exactly. Therefore there are so many confusions and variations of maximum 2 times in loading capacity are come out. In this study, specifications of bi-directional pile load test (BD PLT) were considered. Based on cases of the bi-directional pile load test performed in domestic areas, maximum equivalent test load, test load increasing ratio and sufficiency ratio of design load were analyzed. It can be known that the loading capacity specification of bi-directional pile load test must be defined as 1-directional test load that is established as more than 2 times of design load.

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New Inspection Skill for Load-test of Hydraulic Elevator without Actual Loads (엘리베이터 하중시험 대체 검사기법 개발)

  • Heo, Yun-Seop;Eom, Yong-Gi
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.3
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    • pp.127-132
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    • 2013
  • In order to check traction of the elevator, the load-test is positively necessary on the inspection of elevator in Korea. So actual loads are used in the elevator car for the load-test. However, some of advanced countries in Europe, for example Germany, are using the alternative method with no load test instead of traditional load-test. Commonly hydraulic elevator, compared to passenger elevator is mainly used for loading heavy weights. It requires a great deal of labor to carry out load-test. The reason is why we developed a new inspection skill for the load-test of hydraulic elevator without actual loads. The results of studies show that the new method of the load-test can be replace the traditional load-test.

Transformation of Flight Load to Test Load for the Static Load Test of External Fuel Tank for Aircraft (항공기용 외부연료탱크 정하중시험을 위한 비행하중의 시험하중으로의 변환)

  • Kim, Hyun-gi;Kim, Sung Chan;Park, Sung Hwan;Ha, Byoung Geun;An, Su Hong;Kim, Jun Tae
    • Journal of Aerospace System Engineering
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    • v.15 no.1
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    • pp.80-85
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    • 2021
  • In this study, for conducting a static load test of an external fuel tank used for an aircraft, the flight load acting on the external fuel tank was converted to the test load and the suitability of the converted test loads was confirmed. In order to calculate the test load from the flight load, the external fuel tank was divided into several sections. Shear load, moment by unit shear load, and unit moment were calculated for each section. Test loads for each section were then calculated by computing the shear load, the moment of each section, and flight load condition. In actual static load tests, it might not be possible to impose the test load in the calculated position due to physical constraints. Therefore, after determining positions in which the load could be imposed in the actual test, the test load calculated for each section was redistributed to selected positions. Finally, a test load plan was established by applying a whiffle tree to enhance the efficiency of the test performance while making it easier to operate the actuator. The reliability of the test load plan was verified by comparing it with flight load conditions.

A Study on the Loading Capacity Standard of Bi-directional Pile Load Test (BD PLT) (양방향말뚝재하시험의 재하용량 기준에 관한 연구)

  • Choi, Yongkyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6C
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    • pp.379-388
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    • 2008
  • In the bi-directional pile load test (BD PLT) for pile load tests of Mega pile foundations, loading capacity standard is not specified exactly. Therefore there are so many confusions in performing the BD PLT and variations up to maximum 2 times in loading capacity are come out. In this study, standards of bi-directional pile load test (BD PLT) were considered. Based on cases of the bi-directional pile load test performed in domestic areas, maximum equivalent test load, test load increasing ratio, loading capacity increasing ratio and sufficiency ratio of design load were analyzed. It could be known that the loading capacity standard of bi-directional pile load test must be defined as 1-directional loading capacity and also must be established as more than 2 times of design load.

A Comparative Study on the Bearing Capacity of Dynamic Load Test and Static Load Test of PHC Bored Pile (PHC 매입말뚝의 동재하시험과 정재하시험의 지지력 비교·분석 연구)

  • Park, Jongbae
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.9
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    • pp.19-31
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    • 2017
  • In case of USA, the drilled shaft and the driven pile in the field showed a good correlation in the analysis of the bearing capacity between the dynamic load test and the static load test. However, in Korea, we mainly install the bored pile, which is not widely used overseas and we tried to confirm the reliability of the dynamic load test on the bored pile, because many people questioned the reliability of it. In this study, load tests were carried out on PHC bored piles in LH field (Cheonan, Incheon, Uijeongbu), and the bearing capacity of the dynamic load test (EOID 7times, Restrike 7times) and the static load test (7times) were compared and analyzed. As a result, the average of the bearing capacity of the static load test was 27% higher than that of the dynamic load test (reliability : 0.73, coefficient of variation : 0.3). And the average of the bearing capacity of the static load test (Davisson) was 27% higher than that of the bearing capacity of the dynamic load test (Davisson) (reliability : 0.73, coefficient of variation : 0.2). To reduce the difference between the bearing capacity of the dynamic load test and the static load test, we proposed modified bearing capacity of dynamic load test (base bearing capacity of EOID + skin frictional force of restrike) and difference between the bearing capacities was reduced to 9% (reliability : 0.91, coefficient of variation : 0.2). And the coefficient of variation was reduced to 0.2 and the consistency of analysis increased.

Behavior of Geogrid-Reinforced Soil with Cyclic plate Load Test (반복 평판재하시험을 통한 지오그리드 보강지반의 거동 특성)

  • 신은철;김두환;이상조;이규진
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.285-292
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    • 1999
  • The cyclic plate load test were peformed to determine the behavior of reinforced soft ground with multiple layers of geogrid. Five series of test were conducted with varying the soil profile conditions which including the ground level, type of soil, and the thickness of each soil layer. The plate load test equipment was slightly modified to apply the cyclic load. Based on the cyclic plate load test results, the bearing capacity ratio(BCR), subbase modules, shear modules, the elastic rebound ratio, and reinforcing parameters are presented.

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Evaluation of Bridge Load Carrying Capacity of PSC Girder Bridge using Pseudo-Static Load Test (의사정적재하시험을 이용한 PSC 거더교의 공용 내하력평가)

  • Yoon, Sang-Gwi;Shin, Soobong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.4
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    • pp.53-60
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    • 2019
  • In this study, a method for updating the finite element model of bridges with genetic algorithm using static displacement were presented, and verified this method using field test data for PSC girder bridge. As a field test, static load test and pseudo-static load test were conducted, and updated the finite element model of test bridge using each test data. Finally, evaluated the bridge load carrying capacity with updated model using pseudo-static load test's displacement data. To evaluate the bridge load carrying capacity, KHBDC-LSD, KHBDC and AASHTO LRFD's live load model were used, and compared the each results.

Development of accelerated life test method for the wind turbine Gearbox using cumulative damage theory (누적손상이론을 이용한 풍력증속기의 가속수명시험법 개발)

  • Son, Ki-Su;Kwak, Hee-Sung;Kang, Change-Hoon;Cho, Jun-Haeng
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.11a
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    • pp.693-697
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    • 2005
  • This study was performed to develop accelerated life test method of the wind-turbine gearbox using accumulated damage theory that used to model the fatigue of parts that receive variable load. The accumulated damage theory was introduced, and the estimation of life and calculation of accelerated life test time was illustrated. As the actual application example, accelerated life test method of the gearbox was described. Life distribution of the wind-turbine gearbox was supposed to follow Weibull distribution and life test time was calculated under the conditions of average life (MTBF) 140,600 hours and 99% reliability for one test sample According to the accumulated damage theory, because test time can shorten in case increase test load, test time could be reduced by 1.2 years when we put the load 1.2 times of rated load than 0.93 times of rated load that is equivalent load calculated by load spectrum of the wind turbine. This time, acceleration coefficient was 21.3. This accelerated test method was used to develop accelerated test method of gear reducer, gear and bearing as well as the industrial gearbox and it is considered to be applied comprehensively to mechanical parts the fatigue of which is happened by load or pressure etc.

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Development of Accelerated Life Test Method for Machanical Parts Using Cumulative Damage Theory (누적손상이론을 이용한 기계류부품의 가속수명시험법 개발)

  • Kim, Dae-Cheol;Lee, Geun-Ho;Kim, Hyeong-Ui
    • 연구논문집
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    • s.32
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    • pp.35-43
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    • 2002
  • This study was performed to develop accelerated life test method of machanical parts using cumulative damage theory that used to model the fatigue of parts that receive variable load. The cumulative damage theory was introduced, and the estimation of life and calculation of accelerated life test time was illustrated. As the actual application example, accelerated life test method of agricultural tractor transmission was described. Life distribution of agricultural tractor transmission was supposed to follow Weibull distribution and life test time was calculated under the conditions of average life (MTBF) 3,000 hours and 90% reliability for one test sample. According to the cumulative damage theory, because test time can shorten in case increase test load, test time could be reduced by 482 hours when we put the load 1.1 times of rated load than 0.73 times of rated load that is equivalent load calculated by load spectrum of the agricultural tractor. This time, acceleration coefficient was 11.7. This accelerated test method was used to develop accelerated test method of gear reducer, hydraulic hose and bearing as well as agricultural tractor transmission and it is considered to be applied comprehensively to machanical parts the fatigue of which is happened by load or pressure etc.

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Comparison and Evaluation of Load Test Methods for Aluminum Car Body (알루미늄 차체 하중 시험 방법에 관한 비교 평가)

  • 서승일;박춘수;신병천
    • Journal of the Korean Society for Railway
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    • v.7 no.1
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    • pp.32-36
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    • 2004
  • Aluminum carbody for rolling stocks is light and perfectly recycled, but includes severe defects which are very dangerous to fatigue strength. Static load test has been performed up to date to assess structural safety of the carbody. However, static load test is not sufficient to evaluate fatigue strength of the carbody, because fatigue failure is caused by dynamic load. In this study, the established load test methods for carbody are described and the characteristics of the methods are discussed. Also, a testing method to simulate dynamic loading condition is proposed for evaluation of fatigue strength of the carbody. The results by the proposed testing method are compared with the results by the static load test and new findings are discussed.