• 조명전기설비학회논문지
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• 제23권7호
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• pp.67-74
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• 2009

This paper describes the speed control functions of the typical steam turbine speed controllers and the test results of generator load rejection simulations. The goal of the test is to verify the speed controller's ability to limit the steam turbine's peak speed within a predetermined level in the event of generator load loss. During normal operations, the balance between the driving force of the steam turbine and the braking force of the generator load is maintained and the speed of the turbine-generator is constant. Upon the generator's load loss, in other word, the load rejection, the turbine speed would rapidly increase up to the peak speed at a fast acceleration rate. It is required that the speed controller has the ability to limit the peak speed below the overspeed trip point, which is typically 110[%] of rated speed. If an actual load rejection occurs, a substantial amount of stresses will be applied to the turbine as well as other equipments, In order to avoid this unwanted situation, not an actual test but the other method is necessary. We are currently developing the turbine control system for another nuclear power plant and have plan to do the simulation suggested in this paper.

• 드라이브 ㆍ 컨트롤
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• 제12권1호
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• pp.15-20
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• 2015

For testing a newly designed ship's steering gear, a steering gear test bench with a steering gear to be tested and a load generation part should be prepared. The load given to the steering gear has to be pertinent to the load generated in a targeted ship. In this study, the authors suggest a process of estimating the load given to steering gears in ships. At first, a test for measuring the load in the steering gear of a real ship was conducted. Then, a process was developed to compute rudder driving torque and force by using basic equations including some empirical equations on ship's steering. The test results and the computation results on the load in the steering gear were compared, As a result, the process suggested in this study for estimating load in ship's steering gears was verified.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.201-205
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• 2001

This paper presents the load modeling process and bus load models for KEPCO power system. At first, load devices commonly used in KEPCO power systems were selected, and tested for measuring the voltage and frequency sensitivity of active and reactive power. From this test, about 40 voltage and frequency dependent load models have been obtained. The bus load composition rate for KEPCO power system has been determined using the various recent surveys and papers in order to develop the load model for a power system bus. To verify the accuracy of developed bus load models, the field test for measuring active and reactive power according to artificial variation of the bus voltage was performed at 8 substations for spring summer, autumn, winter cases. With data of this seasonal field test, more reliable bus load models for KEPCO power systems were developed.

• 한국철도학회논문집
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• 제9권6호
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• pp.784-791
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• 2006

This paper presents the test results to evaluate the healthiness of the ballast in subway. The test includes the dynamic load test in servicing Line the screen classification test of aggregates and the wear test. From the results, the aspect and the property of the ballast are evaluated. The dynamic load tests explain the relationship between the deterioration of the ballast and the fluctuation of loads. The assessment of impact factor based on the field test results in a good property of test blocks is proposed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.484-493
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• 2006

This paper is presented the test results to evaluate the healthiness of the ballast in subway. The test includes the dynamic load test in servicing Line the screen classification test of aggregates and the wear test. From the results, the aspect and the property of the ballast are evaluated. The dynamic load tests the relationship between the deterioration of the ballast and the fluctuation of loads. The assesexplain sment of impact factor based on the field test results in a good property of test blocks is proposed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.993-1000
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• 2009

In general, a drilled shaft embedded in weathered rock has a large load bearing capacity. Therefore, most of the load tests are performed only up to the load level that confirms the pile design load capacity, and stopped much before the failure load of the pile is attained. If a reliable failure load value can be extracted from the premature load test data, it will be possible to greatly improve economic efficiency as well as pile design quality. The main purpose of this study is to propose a standard for judging the reliability of the failure load of piles that is obtained from extrapolated load test data. To this aim, eleven static load test data of load-displacement curves were obtained from testing of piles to their failures from 3 different field sites. For each load-displacement curve, loading was assumed as 25%, 50%, 60%, 70%, 80%, and 90% of the actual pile bearing capacity. The limited known data were then extrapolated using the hyperbolic function, and the failure load was re-determined for each extrapolated data by the ASCE 20-96 method (1997). Statistical analysis was performed on the reliability of the re-evaluated failure loads. The results showed that if the ratio of the maximum-available displacement to the failure-load displacement exceeds 0.6, the extrapolated failure load may be regarded as reliable, having less than a conservative 20% error on average. The applicability of the proposed standard of judgment was also verified with static load test data of driven piles.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1434-1441
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• 2005

For anchored system applications, each ground anchor is tested after installation and prior to being put into service to loads that exceed the design. This load testing methodology, combined with specific acceptance criteria, is used to verify that the ground anchor can carry the design load without excessive deformations and that the assumed load transfer mechanisms have been properly developed behind the assumed critical failure surface. After acceptance, the ground anchor is stressed to a specified load and the load is locked-off. The two types of load tests conducted during the research program included performance test and creep test which were carried out in accordance with testing procedures by AASHTO(AASHTO 1990) and FHWA(Weatherby 1998) at Samsung-Dong 00 Site. Form the measurements, ultimate load and creep rate of anchors are proposed for straight shaft pressured grouted anchors in waste landfill. The load distribution on the grout was obtained from the measured strain data at each fraction of the ultimate load during the load tests.

• 항공우주기술
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• 제10권2호
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• pp.146-153
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• 2011

복합재 항공기의 설계하중 데이터로부터 전기체 구조시험 중에 하중부가용 스트랩에 부가될 시험하중의 크기를 산출하는 몇 가지 방법에 대하여 비교 분석하였다. 이 방법들을 KC-100 복합재 항공기 좌측 주익의 시험하중 산출과정에 적용해보고 산출된 결과의 특성 및 차이를 분석하였다. 항공기 전기체 구조시험에 부가되는 시험하중은 각 항공기의 설계 하중의 특성 및 하중부가용 스트랩의 위치 등에 따라 그 크기가 다르게 결정되므로 본 연구에서 소개하는 시험하중 산출방법을 모두 적용하여 결과를 비교해보고 최종적으로 적합한 방법을 선정하는 과정이 필요하다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.539-545
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• 2010

The field plate test has a good potential for determining since it measures both plate pressure and settlement. The deformation modulus of rock mass is differently measured for status of structures. The values of deformation modulus are obtained from laboratory test (uniaxial and triaxial test) and field test (pressuremeter test). Plate load test should be conducted by different loading plate sizes for geological structure of rock mass and scale of structures. In this paper, large plate load tests were performed to predict of structure's behavior and evaluate the ultimate bearing capacity of the foundation on soft rock. Simultaneously, deformation modulus of rock mass was estimated by back analysis of stresses measured in field test under rock mass. Finally, we verified the validation of deformation modulus of rock mass through result of large plate load test and numerical simulation.

• 한국항공우주학회지
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• 제42권1호
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• pp.67-75
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• 2014

항우연에서는 복합재 소형항공기(KC-100)에 대하여 15가지 전기체 시험조건과 7개의 국부적 시험조건들에 대한 전기체 정적구조시험을 수행하였다. 시험요구도, 시험일정, 시험체 및 더미구조, 시험하중산출, 시험장치, 시험장비 등을 소개하였다. 수십개의 제어채널을 사용하는 전기체 구조시험의 하중제어의 정확도를 살펴보기 위하여 U1의 시험데이터를 분석하였다. 분석결과 각 채널별 데이터 획득된 하중값은 허용오차인 SNPE(Static null pacing error)값 이내에서 잘 유지하고 있음을 보였고 본 논문의 저자가 제안한 시험의 하중제어오차 크기 정의방법을 적용한 결과 U1 시험의 하중제어 오차값이 8.6N 이었고 나머지 전기체 시험조건들에 대한 시험데이터를 분석한 결과도 보였다. 마지막으로 U1시험에서 자세제어장치에서 측정된 반력들이 시험하중 증가와 함께 변하는 것을 보였고 전기체 구조시험에서 반력변화 발생의 요인들에 대하여 기술하였다.