• Title/Summary/Keyword: 재료 모사

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A Study of MD Constitutive Model Calibration for Coarse-grained Soils (조립재료에 대한 MD 구성모델 캘리브레이션 연구)

  • Choi, Changho;Shin, Dong-Hoon
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.1
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    • pp.63-72
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    • 2013
  • The structural stability of fill dam largely depends on the engineering behavior of rock materials used as main zone for dam construction and it is necessary to understand well the stress-strain characteristics of fill materials as well as shear strength property. In addition, the numerical analysis of fill dam requires a thorough study for calibrating material properties and parameters of a coarse-grained soil constitutive model. In this paper, large triaxial test results for Buhang-dam fill materials are analyzed and constitutive model parameters are calibrated based on the test results. It is shown that MD constitutive model is capable to predict the stress-strain behavior of dense and loose coarse-grained soils used for Buhang-dam construction based on the comparison study between the experimental test result and numerical simulation.

Eddy Current simulation according as laminating form of magnetic material (자성재료 적층 형태에 따른 Eddy Current 전산모사)

  • Park, Seung-Hyuk;Kim, Cheon-Ho;Hwang, Sun-Mook;Choi, Jin-Su
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1211-1212
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    • 2015
  • 일반적으로 마그네틱 코어(magnetic core)가 삽입되어 있는 구조의 변압기의 에너지 효율을 높이고 적절한 주파수 대역에서 작동시키기 위해서는서 자성체를 이용하여 eddy current를 줄여야 한다. 본 논문에서는 자성체의 적층 형태에 따라 어떻게 eddy current가 영향을 받는지에 대한 전자기적 전산모사를 실시하였다.

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Friction and wear properties of carbon fiber reinforced epoxy composite for the artificial hip joint application (인공고관절 모사조건하에서의 탄소섬유 복합재료의 마찰 및 마모 특성)

  • 송영석;윤재륜
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 1999.11a
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    • pp.239-241
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    • 1999
  • Recently, the friction and wear behaviors of UHMWPE, ceramic and metal is being researched actively for the use as an artificial hip-joint. In this study, because of good wear properties of carbon fiber, we made experiments about the friction and wear of carbon fiber reinforced epoxy composite under the lubricative and the dry condition. The possibilities of carbon-carbon composite for the artificial hip joint application was studied from this results.

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End-Terminal Capping Effect on Mechanical Property of Transthyretin (TTR105-115) Amyloid Fibril (End-terminal Capping 효과가 아밀로이드 섬유의 기계적 특성에 미치는 영향 연구)

  • Choi, Hyunsung;Lee, Myeongsang;Na, Sungsoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.7
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    • pp.621-627
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    • 2017
  • The understanding of the mechanical properties of amyloid fibers, which induce various neurodegenerative diseases, is directly related to the amyloid growth mechanism. Diverse studies have been performed on amyloid fibers from the viewpoint of disease epidemiology. Recently, attempts have been made to use amyloid fibers as new materials because of their notable mechanical properties and self-aggregation abilities. In this study, the mechanical properties of transthyretin (TTR105-115), which induces cardiovascular disease, were evaluated using a molecular dynamics (MD) simulation. In particular, the effect of the end-terminal capping on the structural stability of TTR105-115 was evaluated. The mechanical behavior and properties of TTR105-115 were measured by steered molecular dynamics (SMD). We clarified the factors affecting the mechanical properties of these materials and suggested the possibility of utilizing them as nature inspired materials.

A Study on the Resin Flow through Fibrous Preforms in the Resin Transfer Molding Process (수지이동 성형공정에서 섬유직조망내의 수지유동에 관한 연구)

  • 김성우;이종훈;이미혜;남재도;이기준
    • Composites Research
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    • v.12 no.2
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    • pp.70-81
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    • 1999
  • Resin transfer molding(RTM) as a composite manufacturing process is currently of great interest in the aerospace industry requiring high performance composite parts. In this study, an analysis of mold filling in the RTM process was carried out by numerical simulation using finite element/control volume technique. Experimental work for the visualization of resin flow through fibrous preform was also conducted in order to quantitatively measure the permeabilities of the fiber mats and to evaluate the validity of the developed numerical code. The different types of fiber mats and silicon oils were selected as reinforcements and resin materials, respectively. The effects of fibrous preform structure, mold geometry, and preplaced insert on the flow front patterns during mold filling were examined by integrating the model predictions and experimental results. The flow fronts predicted by numerical simulation were in good agreement with those observed experimentally. However, according to the regions of the mold, some deviations between predicted and observed flow fronts could be found because of non-uniform fiber volume fraction. Weldline locations for the resin flow through round insert preplaced in the mold could be qualitatively deduced based on predicted flow fronts.

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Performance Parameter of Tissue Mimicking Material measuring Ultrasonic Thermal Index (초음파 열지수 측정용 조직모사 물질의 성능계수)

  • Kim Yong Tae;Jho Moon Jae;Yun Yong Hyeon;Kim Ho Chul
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.369-370
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    • 2004
  • 초음파의 조차에 의한 인체내부의 온도상승의 측도로 열지수(thermal index)가 사용되고 있으며, 이는 주파수 및 음향파워에 의존한다. 초음파 조사에 의한 인체내부의 온도상승을 평가하는데 사용되는 재료를 조직 모사 물질이라 한다. 본 논문아사는 단위 음향파워에 대한 온도 변화인 열 감도(thermal sensitivity)를 새로이 정의하였으며, 이 물리량으로 조직모사물질의 성능을 평가 할 수 있다는 것을 제안하고자 한다.

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Facture Simulation using Molecular Dynamics on a PC Cluster (PC 클러스터 상에서 분자동역학을 이용한 파괴 모사)

  • Choi, Deok-Kee;Ryu, Han-Kyu
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.252-257
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    • 2001
  • With the help of newly arrived technology such as PC clustering, molecular dynamics (MD) seems to be promising for large-scale materials simulations. A cost-effective cluster is set up using commodity PCs connected over Ethernet with fast switching devices and free software Linux. Executing MD simulations in the parallel sessions makes it possible to carry out large-scale materials simulations at acceptable computation time and costs. In this study, the MD computer code for fracture simulation is modified to comply with MPI (Message Passing Interface) specification, and runs on the PC cluster in parallel mode flawlessly. It is noted that PC clusters can provide a rather inexpensive high-performance computing environment comparing to supercomputers, if properly arranged.

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