• Title/Summary/Keyword: Major Element

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Design Technique for Improving the Durability of Top Coating for Thermal Barrier of Gas Turbine (가스터빈의 열차폐용 탑코팅의 내구성 향상 설계기술)

  • Koo, Jae-Mean;Seok, Chang-Sung
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.1
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    • pp.15-20
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    • 2014
  • Thermal barrier coating (TBC) is used to protect the substrate and extend the operating life of the gas turbine for a power plant and an aircraft. The major cause of failure of such a coating is the spallation of coating, and it results from the thermal stress between top coating and bond coating. To improve the durability of TBC system, the dense vertical cracked (DVC) coating method to insert vertical cracks is applied to a gas turbine blade. In this study, a criterion for the design of vertical crack in the DVC coating was presented using the finite element analysis.

A Study on Preference for telecommuting Center design Criteria (텔레커뮤팅 센터의 실내공간계획요소에 대한 선호 조사 연구)

  • 하미경;권미연
    • Korean Institute of Interior Design Journal
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    • no.20
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    • pp.91-97
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    • 1999
  • Telecommuting becomes a new form of work according to the development of information technology. Therefore, the purpose of this study is to provide basic data for the interior space planning of telecommuting centers by means of surveying office workers' opinions. The major findings of this research are as follows. The opinion about whether to use telecommuting center if provided is showed highly positively. In the matter of space type of telecommuting center, 'mixing type I (open plan office but division with high partition)' is the most preferred, the next, is 'closed type'. The most preferred type of workstation is 'independent type', the next is 'X type' and the third is 'link type'. Preferred partition height is '1,300-1,500mm'. When planning telecommuting center, the most important element of space plan is 'size and layout of workstation' and the second is 'private space for confidential work'. In public workplace, the most important element 'refreshment space', and the second one is 'mailing system'.

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A Study on the Finite Element Modeling Methods of Large Navy Shipboard Equipment Attached to the Top and Bottom Foundations for DDAM (상.하 받침대를 갖는 대형 함정 탑재장비의 DDAM 해석을 위한 유한요소 모델링 기법에 관한 연구)

  • Song, Oh-Seop;Kim, Yong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.4 s.121
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    • pp.317-323
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    • 2007
  • Non-contact underwater explosions against surface ships could cause extensive equipment damage and render the ship inoperative. As an analytical method, DDAM(dynamic design and analysis method) is used for ship shock design. In this paper, in order to verify the finite element model of large shipboard equipment, modal test of equipment was performed. Major objective of this paper is to describe shock analysis methodology for large shipboard equipment attacked to the top and bottom foundations.

A Study on the Thermal deformation during Heat-Treatment (열처리시의 열변형에 관한 연구)

  • Jang J. W.;Kim D. J.;Kang J. H.;Kang S. S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.161-166
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    • 2001
  • The distortion and fracture of heat treated components is a major industrial problem, which may considerably increase the costs of operations that involve high cooling rates. And also, thermal deformation would be generated during Heat Treatment. In this paper, the purpose is to check out the thermally deformed components during heat treatment and to analyze thermal deformation and thermal stress by two dimensional Finite Element Method. And two dimensional FEM program is evaluated for heat transfer and thermal deformation.

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An Engine Structure-Borne Noise Analysis by Finite Element Method (유한요소법에 의한엔진 구조소음 해석)

  • 안상호;김주연;김규철
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.1
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    • pp.122-133
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    • 1998
  • This paper presents the static analysis, the modal analysis and the forced vibration analysis on engine structures to find out the structure-borne noise sources by finite element method. The deformation of engine structures under the maximum combu- stion gas force was calculated through the static analysis, and the resonance possibilities were predicted by the modal analysis which ascertains mode shapes and the corresponding frequencies of engine global and its major noise sources in engine surfaces were investigated with the forced vibration analysis by means of finding the transfer mobilities on engine surfaces due to the piston impact and the velocity levels due to the combustion in consideration of oil film stiffness and damping coefficients. Finally, the direction of engine structure-borne noise reduction can be estabilished by the above-mentioned analysis procedure and the reduction effect of cost on proto-type engine build-up is expected.

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A Test Verified Model Development Study for Seismic Qualification(Safety) (내진검증(안전)을 위한 실험적 고찰을 이용한 해석 모델 개발연구)

  • Uk-Hwan Sur
    • Journal of the Korean Society of Safety
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    • v.13 no.4
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    • pp.286-291
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    • 1998
  • This paper includes discussion on developing the test verified finite element model for one of the seismic qualification(safety) approaches. It presents a test verified finite element model of a UPS(Uninterruptible Power Supply System) to be used at KMRR, KAERI. The test verified model predicts natural frequencies within 5 percent error for all major modes below 50Hz. This model accurately represents the dynamic characteristics of the actual hardware and is qualified for its use in the final stress analysis for seismic verification.

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The Prediction of Dynamic Recrystallization and Grain Size of 304 Stainless Steel during Hot Deformation (스테인레스 304의 열간동적재결정과 미세조직 예측)

  • Kwon Y. P.;Cho J. R.;Lee S. Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.10a
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    • pp.25-28
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    • 2000
  • The flow stress of 304 stainless steel during high during hot forming process were determined by conducting hot compression tests at the range of 1273 K-1423 K and 0.05 /s-2.0 /s as these are typical temperature and strain rate in hot forging operation. Based on the observed phenomena, a constitutive model of flow stress was assumed as a function of strain, strain rate, temperature. Dynamic recrystallization was found to be the major softening mechanism with this conditions as previous studies. A finite element analysis was performed to predict the recrystallized volume fraction and the mean grain size in hot compression of 304 stainless steel.

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The Prediction of Dynamic Recrystallization and Grain Size of 304 Stainless Steel during Hot Deformation (304 스테인리스강의 열간동적재결정과 미세조직 예측)

  • 권영표;조종래;이성열;이정환
    • Transactions of Materials Processing
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    • v.10 no.7
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    • pp.573-578
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    • 2001
  • The flow stress of 304 stainless steel during hot forming process were determined by conducting hot compression tests at the range of 1273 K∼1423 K and 0.05 /s∼2.0 /s as these are typical temperature and strain rate in hot forging operation. In this material, Dynamic recrystallization was found to be the major softening mechanism with this conditions as Previous studies. Based on the observed phenomena, a constitutive model of flow stress was assumed as a function of strain, strain rate, temperature. In the constitutive model, the effects of strain hardening and dynamic recrystallization were taken into consideration. A finite element method connected to constitutive model was performed to predict the dynamic recrystallization behaviors and also stress-strain curves in hot compression of 304 stainless steel.

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Dynamic Analysis of Plate Girder Bridge Using Object-Oriented Technique (객체지향기법을 이용한 플레이트 거더교의 동해석)

  • Cho, Jeong-Rae;Kwark, Jong-Won;Chin, Won-Jong;Choi, Eun-Suk;Kang, Jae-Yoon;Lee, Jung-Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.486-489
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    • 2006
  • This paper presents a newly proposed object-oriented finite element framework and its applications on dynamic analysis of plate girder bridge. The developed framework supports various types of finite elements, materials, constraints, loads, and solution methods. One major feature different from other object-oriented finite element programs is that static model and dynamic state can be easily read from or written to a file. In addition, the framework supports efficient DOF pattern handling for a node connecting elements with different DOF patterns, new multi-point constraint handling, and various scripting languages for easy use of the library. In order to show the applicability to dynamic analysis, dynamic moving load analysis on plate girder bridge is performed.

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RepWeb: A Web-Based Search Tool for Repeat-Related Literatures

  • Woo, Tae-Ha;Kim, Young-Uk;Kwon, Je-Keun;Seo, Jung-Min
    • Genomics & Informatics
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    • v.5 no.2
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    • pp.88-91
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    • 2007
  • Repetitive sequences such as SINE, LINE, and LTR elements form a major part of eukaryotic genomes. A literature search tool that summarizes the information contained within repeat elements would provide biologists in the field of genomics with a useful tool for analyzing genomic sequence features. We developed a java program designed to make literature access easier by using two search engines simultaneously. RepWeb is a web-based search system that provides a user friendly interface for searching the reference data and journals for information related to repeat elements by using the search engines, Google Scholar and PubMed, simultaneously. It provides an interface that displays the repeat element- related biological information, and includes useful functions such as the production of a repeat tree, clickable links to PubMed and Google Scholar, exporting, and sorting a field into date, author, journal and title.