• 제목/요약/키워드: model test

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표준 인장시험과 반복하중 C(T) 시험을 이용한 균열해석에서의 Chaboche 복합경화 모델 결정법 (Determination of Chaboche Cyclic Combined Hardening Model for Cracked Component Analysis Using Tensile and Cyclic C(T) Test Data)

  • 황진하;김훈태;류호완;김윤재;김진원;권형도
    • 한국압력기기공학회 논문집
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    • 제15권2호
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    • pp.31-39
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    • 2019
  • Cracked component analysis is needed for structural integrity analysis under seismic loading. Under large amplitude cyclic loading conditions, the change in material properties can be complex, depending on the magnitude of plastic strain. Therefore the cracked component analysis under cyclic loading should consider appropriate cyclic hardening model. This study introduces a procedure for determining an appropriate cyclic hardening model for cracked component analysis. The test material was nuclear-grade TP316 stainless steel. The material cyclic hardening was simulated using the Chaboche combined hardening model. The kinematic hardening model was determined from standard tensile test to cover the high and wide strain range. The isotropic hardening model was determined by simulating C(T) test under cyclic loading using ABAQUS debonding analysis. The suitability of the material hardening model was verified by comparing load-displacement curves of cyclic C(T) tests under different load ratios.

업데이트된 집중질량스틱모델과 진동대실험 지진응답 비교 (Comparison of Seismic Responses of Updated Lumped-Mass Stick Model and Shaking Table Test Results)

  • 선휘창;홍상현;노화성
    • 한국지진공학회논문집
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    • 제23권4호
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    • pp.231-238
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    • 2019
  • A conventional lumped-mass stick model is based on the tributary area method to determine the masses lumped at each node and used in earthquake engineering due to its simplicity in the modeling of structures. However the natural frequencies of the conventional model are normally not identical to those of the actual structure. To solve this problem, recently an updated lumped-mass stick model is developed to provide the natural frequencies identical to actual structure. The present study is to investigate the seismic response accuracy of the updated lumped-mass stick model, comparing with the response results of the shaking table test. For the test, a small size four-story steel frame structure is prepared and tested on shaking table applying five earthquake ground motions. From the comparison with shaking table test results, the updated model shows an average error of 3.65% in the peak displacement response and 9.68% in the peak acceleration response. On the other hand, the conventional model shows an average error of 5.15% and 27.41% for each response.

소프트웨어 시험 노력 추정 시그모이드 모델 (Sigmoid Curve Model for Software Test-Effort Estimation)

  • 이상운
    • 정보처리학회논문지D
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    • 제11D권4호
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    • pp.885-892
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    • 2004
  • 소프트웨어 시험단계에 투입되는 노력의 분포를 추정하는 대표적인 모델로 Weibull 분포(Rayleigh와 지수분포 포함)가 있다. 이 모델은 시험 시작시점에서 실제로 많은 노력이 투입되는 점을 표현하지 못한다. 또한 다양한 형태를 갖고 있는 실제 시험 노력의 분포를 적절히 표현하지 못하고 있다. 이러한 문제점을 해결하기 위해 본 논문은 시그모이드 모델을 제안하였다. 신경망 분야에서 적용되고 있는 시그모이드 함수로부터 소프트웨어 시험 노력을 적절히 표현할 수 있도록 함수 형태를 변형시켰다 제안된 모델은 다양한 분포 형태를 보이고 있는 실제 수행된 소프트웨어 프로젝트로부터 얻어진 6개의 시험 노력 데이터에 적용하여 적합성을 검증하였다. 제안된 시그모이드 모델은 기존의 Weibull 모델보다 성능이 우수하여 소프트웨어 시험노력을 추정하는데 있어 와이블 모델의 대안으로 채택될 수 있을 것이다.

원심모형실험을 통한 전석층이 존재하는 제방에서의 파이핑 현상 모사 (Reproduction of Piping Failure Due to the Permeable Layer Using Centrifuge Test)

  • 진석우;김남룡;김동수
    • 대한토목학회논문집
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    • 제31권1C호
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    • pp.1-10
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    • 2011
  • 본 논문에서는 제방 제체 하부지반에 투수계수 차이가 많이 나는 투수층(전석층)이 존재하는 김포제방에서 발생한 파이핑 현상을 모형실험 중 하나인 원심모형시험을 이용하여 모사하였다. 또한 원심모형실험과 동일 조건을 대상으로 수치해석을 수행하여 원심모형실험 결과와 비교하였다. 우선, 김포 제방을 바탕으로 원심모형실험을 수행할 단면을 결정하고, 간극수압계를 매설한 모형 제방에서 원심모형실험을 수행하였다. 실험을 통해 대부분의 물이 전석층으로 흐르는 것을 확인 하였으며 그로 인해 파이핑 현상이 발생하였다. 비디오 카메라 영상을 통해 기존의 연구 결과와 같이 전석층과 제내지 측 지표면과 거리가 가장 짧은 부분에서의 파이핑 현상을 확인하였다. 간극수압계를 통해 획득된 수압 분포 특성도 전석층으로의 물의 흐름으로 인해 파이핑 현상이 발생한 것임을 확인시켜주었다. 수치해석 결과 또한 원심모형실험 결과와 동일한 위치에서 파이핑 현상이 발생하는 것을 확인하였다. 원심모형시험을 통해 제방에서의 파이핑 현상을 모사하였으며 추후 제방 연구에서 원심모형시험을 이용하여 다양한 실험 및 현상을 평가, 예측 할 수 있을 것이라 판단된다.

유압 저하시험 모델과 자동차 연료필터의 토설율 측정 실험 연구 (A Study on Hydraulic Drawdown Test Model and Experimental Estimation of Desorption Rate Ratios of Fuel Filters)

  • 이재천;계중읍
    • 한국정밀공학회지
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    • 제20권9호
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    • pp.205-213
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    • 2003
  • This study describes the mathematical equation of drawdown test model and introduces the experimental test apparatus and procedure to estimate the desorption rate ratio of a filter. The characteristics of a hydraulic filtration system of drawdown test were demonstrated by numerical simulation for various properties of filters and operation conditions. Experiments for three kinds of fuel filters were conducted according to the proposed test method. And the test results of desorption rate ratio were compared with those values anticipated in precedent multipass filtration tests. Experimental results revealed the validation of drawdown test method proposed in this study. Domestic fuel filter yielded high desorption rate ratio comparing with other foreign products, which means that the Beta ratio decreases a lot during the test. The results also showed that filtration system model could be developed including desorption rate ratio to estimate the variable Beta ratio in service life.

FAA AC120-40B Level D급 T-50 전술훈련 시뮬레이터 (Development of FAA AC120-40B Level D Flight Dynamics Model for T-50 Full Mission Trainer)

  • 전대근;이세원
    • 한국항공운항학회지
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    • 제14권2호
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    • pp.9-16
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    • 2006
  • FAA AC120-40B Level D flight dynamics model for T-50 Full Mission Trainer was successfully developed. Since AC120-40B Level D requires the quantitative validation tests for simulation model compared with flight test data, T-50 flight test data for each validation test item was gathered, and also automatic test environments which include AFT (Automatic Fidelity Tester) and STA (Simulation Test Analyzer) were developed. The final test results after the iterative test-tuning processes were all within the tolerances specified in AC120-40B Level D. Qualification Test Guide, QTG contains the detail test processes and results.

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댐 하류 만곡부 하천에 대한 수리학적 특성 연구 (A Study on Hydraulic Characteristics of the Curved Channel in the Downstream of Dam)

  • 최한규;백효선;이계윤
    • 산업기술연구
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    • 제25권A호
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    • pp.3-14
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    • 2005
  • In order to accurately analyze the detailed hydraulic characteristics of the curved channel in the downstream of dam with the hydraulic structures such as bridge piers, RMA2 model which is one of two-dimensional models is applied to ChunCheon dam downstream curved channel. A series of hydraulic model tests are carried out for comparison studies. HEC-RAS model is also applied to the same site. There are no errors when velocities and water levels resulted from HEC-RAS model RMA2 model are compared with those of hydraulic model test on the straight channel. But, it is found that results of RMA2 model have a better agreement with those of hydraulic model test than those of HEC-RAS model on the curved channel with bridge piers. Additionally, RMA2 model can be predicted the eddy phenomena around bridge piers of the curved channel.

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In vivo Supravital Staining Micronucleus Test에 의한 $\beta$-Carotene과 Galangin의 소핵생성억제효과 (Anticlastogenicity of $\beta$-Carotene and Galangin using in vivo Supravital Staining Micronucleus Test)

  • 허문영;김정한;류재천
    • 한국환경성돌연변이발암원학회지
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    • 제17권2호
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    • pp.92-96
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    • 1997
  • The micronucleus test using peripheral blood reticulocytes (RETs) was evaluated in ICR mice treated with N-methyI-N-nitrosourea (MNU) and benzo(a)pyrene [B(a)P] as model clastogens. The frequency of micronucleated reticulocytes (MNRETs) in both positive compounds was similar to other results which were reported previously. On the other hand, an anticlastogenic effect of the natural antioxidant, $\beta$-carotene and one of taroholds, galangin as model anticlastogens were investigated using simultaneous treatment. Mice were treated with a model clastogen alone, or with a model clastogen and a model anficlastogen simultaneously. Both $\beta$-carotene and galangin showed anticlastogenic effects against MNU- or B(a)P-induced micronuclei in mice. However, galangin has stronger activity than $\beta$-carotene. Results from our experiment suggest that the in vivo supravital staining micronucleus test using peripheral blood is useful in the evaluation of clastogenic and anticlastogenic effects.

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시뮬레이션과 모형시험을 통한 핀 안정기의 성능평가 (Performance Evaluation of Fin-Stabilizer by Model Test and Time-domain Simulation)

  • 홍사영;김현조;최윤락;신영균;유병석;이승준
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 추계학술대회 논문집
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    • pp.86-90
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    • 2001
  • Demand of good seakeeping perfomace is increasing for sea going vessels such as cruisers, naval ships and container ships. Especillay roll motion is one of major concerns in evaluation of seakeeping performance due to its large resonace motion. Since large roll resonance motion is mainly arised from inherent small damping. use of additional mechnism to provide roll damping can significantly reduce roll motion. In this paper, a reliable performace evaluation method of fin stabilizer, which is very useful for stabilizing roll motion of mid and high speed vessls, is described. Model test and time domain simulation methods are adopted for performance evaluation in which real operating situation of fin stabilizer can be exactly modelled. Model test and simulation results show good correlations between model test and simulation results.

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철도터널내 압력변동 및 터널 미기압파 저감 시험장치개발에 관한 연구 (Development of a new test facility for the study of pressure transients in tunnel and micro-pressure waves radiated from the tunnel exit on the railroad)

  • 김동현;오일근
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.611-618
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    • 2000
  • The test facility of the 1/60-scale models for the train-tunnel interactions was recently developed to investigate the effects of entry portal shapes, hood shapes and air-shafts for reducing the micro-pressure waves radiating to the surroundings of the tunnel exits by KRRI in Korea. The launching system of train model was chosen as air-gun type. In present test rig, after train model is launched, the blast wave by the driver did not enter to inside of the tunnel model. The train model is guided on the one-wire system from air-gun driver to the brake parts of test facility end. Some cases of the experiments were compared with numerical simulations to prove the test facility.

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